bluuebunny/crossref_metadata_2025 huggingface dataset:
Management and Outcomes of 65 Quadruplet Pregnancies: Sixteen Years' Experience in France
Authors: Pons J.C. , Nekhlyudov L. , Dephot N. , Moal S. Le , Papiernik E.
Published: July 2016

Objective: data on the prognosis and management of multifetal pregnancies are of vital importance, particularly when the option of selective termination is considered. The present study details the obstetric management, neonatal outcome, and follow-up data of 65 quadruplet pregnancies in France.

Methods: to conduct the study, a questionnaire was sent to families registered with the National Association Helping Parents of Multiple Births (Association National d'Entraide des Parents de Naissance Multiples, A.N.E.P.N.M.).

Results: of 116 questionnaires sent to families of quadruplets born between 1972 and 1988, 65 were received. Of these pregnancies, 58 were obtained with ovulation induction agents, 2 with IVF (in vitro fertilization) and GIFT (gamete intrafallopian transfer) and 5 were spontaneous. Diagnosis was made prior to 13 weeks gestation in 87.2% of cases. Most mothers were hospitalized prior to delivery – mean duration of 47 days. The mean gestational age at delivery was 31.2 ± 3 weeks with a prematurity rate of 97%. Cesarean sections were performed in 51 cases and vaginal deliveries in 14. Neonatal and perinatal mortality rates were 68 and 104 per 1000, respectively. Birthweights of quadruplets ranged from 760 to 2455g with a mean of 1615 g.

Conclusion: management of quadruplet pregnancies in France consists of early diagnosis, echographical and clinical monitoring, early reduction of maternal activity and cesarean deliveries. Our management of such pregnancies is of high quality as reflected by our obstetrical results. Lack of adequate management, as perceived by families of quadruplets, exists at two levels: a psychological (lack of psychological support) and a financial (lack of specific help).
Parental Imprinting on Mouse Chromosome 7
Authors: Ferguson-Smith A.C.
Published: July 2016

Genetic studies have shown that both a maternally and paternally inherited copy of mouse chromosome 7 are essential for normal embryogenesis. When the parental dosage is altered, such as in maternal or paternal uniparental disomy for chromosome 7 (UPD7), the resulting embryos die. This is due to the altered dosage of imprinted genes which are normally expressed only from the paternally or maternally inherited chromosome homologue. Several genes on mouse chromosome 7 are subject to parental imprinting. Mutant phenotypes seen in UPD7 embryos and chimaeras can be explained by the altered dosage of some of these genes.

The mechanism(s) that causes genes to be expressed in a parental origin specific manner has not yet been determined but is believed to involve germline specific modifications to DNA and/or chromatin which are acted upon after fertilisation to affect the activity of imprinted genes. Two genes, H19 and Igf2, are located 90kb apart on the distal end of chromosome 7 and are imprinted reciprocally with the maternally inherited allele of HI9 and paternally inherited allele of Igf2 being expressed. We have used UPD7 embryos to identify epigenetic modifications that distinguish the two parental alleles in the H19 and Igf2 domain by comparing DNA and chromatin from normal and maternal UPD cobceptuses. Clear cut differences in DNA methylation and chromatin compaction were observed for the H19 gene with the paternal allele exhibiting promoter methylation and nuclease insensitivity. These were not found in sperm. In addition, no major differences were noted for the Igf2 gene, although subtle parental origin specific modifications were found. These studies suggest that the two genes may share a common regulatory mechanism which controls their reciprocal imprinting.
An Introduction to Genomic Imprinting and Parent of Origin Effects
Authors: Hall J.G. , Lopez-Rangel E.
Published: July 2016

Recent developments in molecular genetics and cytogenetics have allowed for better understanding of the inheritance and expression of genes. Many newly recognized mechanisms such as genomic imprinting, mosaicism, allelic expansion, cytoplasmic inheritance and uniparental disomy have been recognized to play an important role in human heredity.

Genomic imprinting refers to differences in the phenotype which are observed depending on whether the gene was inherited from the father or from the mother. Genomic imprinting is a difficult concept to understand because imprinting has been used loosely to refer to a number of different mechanisms including psychological development, endocrinological actions of cells and protein-protein interactions. Genomic imprinting produces parent-of-origin effects. Parent-of-origin effects is a term that encompasses many of the non-traditional types of inheritance and other genetic and non-genetic mechanisms which show an effect depending on whether they were paternally or maternally derived.
Why is There No Diploid Overdose Effect in Prader-Willi Syndrome Due to Uniparental Disomy?
Authors: Smith A.
Published: July 2016

Due to DNA technology, it is now apparent that the mechanisms of genetic disease are more complex than the model of a gene with biallelic expression in the diploid state. If a gene is imprinted, monoallelic expression is the norm when the chromosomes of a pair are inherited normally from each parent. Uniparental disomy (UPD) is the abnormal situation where both chromosomes of a pair come from the same parent. When the chromosome contains an imprinted gene, UPD may result in nullisomy or disomy for a functional copy of that gene. If there are two imprinted loci on the same chromosome, UPD for that chromosome results in nullisomy for one imprinted gene but functional disomy for the other a “diploid overdose” (DO). This situation has been well demonstrated in the Prader-Willi syndrome (PWS) which is the nullisomic phenotype for the PWS gene(s) on chromosome 15q 11-13. Chromosome 15q11-13 also contains the gene for Angelman syndrome (AS) which has a phenotype distinct from PWS. Both loci are subject to imprinting – in PWS, the imprint is on the maternal chromosome 15, in AS it is on the paternal chromosome 15. All individuals with PWS due to maternal UPD, while functionally nullisomic for the PWS locus, are functionally disomic for the AS locus – a DO situation. Assuming that biallelic expression of an imprinted gene is harmful, one would expect DO for an imprinted gene to produce a phenotypic effect. Cases of PWS due to UPD do not appear to differ from those due to deletion (hypopigmentation in deletional cases can be explained by loss of D15S12 downstream from the critical region). There is no good evidence of DO for the AS locus in PWS due to UPD. Why then was it ‘necessary’ in evolutionary terms to imprint the AS locus and maintain the imprint faithfully for life. A similar situation of two imprinted genes on the same chromosome occurs with IGF2 and H19 on chromosome 11p15. Maternal imprinting for IGF2 and paternal imprinting for H19 is the norm. Paternal UPD in this situation does lead to a DO effect, namely Beckwith-Wiedemann syndrome. The possibility of a DO effect needs to be considered when assessing the phenotypic spectrum of UPD for other chromosomes currently under investigation.
Asynchronous Replication Patterns of Imprinted Genes in Triploid Cells
Authors: Argyriou-Tirita A. , Romanakis K. , Kroisel P. , Haas O. A.
Published: July 2016

Several unique features distinguish imprinted from nonimprinted genes, including the unusual replication behavior the unequal methylation and the differential expression of imprinted alleles [1]. The replication timing in S phase of the two homologous alleles of a normal, nonimprinted gene is highly synchronous [2, 3]. Housekeeping genes replicate early, constitutive heterochromatic regions replicate late and tissue-specific genes replicate earlier when they are expressed than when they are not [2-4]. In contrast, imprinted genes which, by definition, display allele-specific expression replicate asynchronously [2-5].

The relative order of replication of homologous alleles as well as that of different loci can be elegantly compared with fluorescence in situ hybridization (FISH) on interphase nuclei [2-5]. Unreplicated DNA segments give singlet hybridization signals in normal diploid cells, while replicated loci are characterized by doublets. The distribution of these two patterns can be used to determine the S phase replication time of any DNA sequence. Moreover, determination of the singlet/doublet ratio allows a good estimation of the degree of replication asynchrony of two homologous alleles [2-5].

Using cell lines with deletions, disomies or associated FISH-detectable centromeric satellite polymorphisms, Kitsberg et al. [4] found that the paternal allele was the early replicating one in all the imprinted genes which they had analyzed. Subsequently, however, Knoll et al. [5] detected genes in the imprinted Prader-Willi region on chromosome 15, which also displayed other patterns. Therefore, it seems necessary to specify the relative timing of maternally and paternally derived alleles for each individual asynchronously replicating gene. Unfortunately, this is so far only feasible with a very restricted number of sequences.
Preferential Loss of Heterozygosity of Chromosome 7 Loci in Simian Virus 40 t/T Antigen-Induced Mouse Hepatocellular Carcinomas Does Not Involve H-ras Muatations
Authors: Casola S. , Vernucci M. , Ungaro P. , Bruni C.B. , Riccio A.
Published: July 2016

Genetic complementation experiments have indicated that both a maternal and a paternal copy of the distal region of mouse chromosome 7 are essential for normal development [1]. This suggested the presence of genes whose expression is dependent on the gamete of origin in this chromosomal region. Two such imprinted genes, namely insulin-like growth factor II (Igf2) and H19, have been identified so far [2, 3]. The first encodes a peptide with mitotic activity towards several cell types, that contributes significantly to prenatal growth of mammals, whereas the second has, as yet, no defined role and seems not to encode any protein, but works as RNA. (Igf2) and H19 are located 90 kb apart, have similar expression patterns during development and are reciprocally imprinted, since the maternal Igf2 and the paternal H19 alleles are inactive in most fetal tissues [4, 5].
Influence of Mouse-Strain-Specific Factors on Position-Dependent Transgene DNA Methylation Patterns
Authors: Koetsier P.A. , Doerfler W.
Published: July 2016

In previous work from this laboratory, an inverse dependence was established for the adenovirus type 2 E2A late promoter between sequence-specific DNA methylation and promoter activity [1-5; for reviews see ref. 6, 7]. The effect of DNA methylation on promoter activity was also assessed in the transgenic mice, which were obtained from microinjections of unmethylated or in vitroHpaII-premethylated pAd2E2AL-CAT DNA [1] into F2zygotes from B6D2F, (C57BL/6 × DBA/2) hybrid mice. In CAT assays carried out on organ extracts from the pAd2E2AL-CAT mice, the inverse relationship was confirmed [2].

We studied the stability of the pAd2E2AL-CAT DNA methylation patterns in up to eight mouse generations and assessed the influence of the strain-specific genetic background. Three pAd2E2AL-CAT mouse lines were crossed with inbred DBA/2, C57BL/6 or B6D2F, mice. Parent-of-origin effects were controlled by exclusive hemizygous transgene transmission either via females or males. The founder animal of line 7-1 carried two groups of transgenes (A and B) on separate chromosomes. The transgene methylation patterns of the 7-1B transgenes and those of the lines 5-8 and 8-1 were stably transmitted.

Southern blot hybridization experiments [8, 9] revealed that the 7-1A transgene methylation pattern was a cellular mosaic. In mixed-genetic-background offspring from 7-1A animals, 10% carried transgenes withHpaII-DNA methylation levels that were reduced from 40 to 10-15%. This finding suggested that in this background the factors that supported high methylation levels were dominant. When inbred DBA/2 mice were the mates, 40% of the siblings carried demethylated transgenes, whereas this ratio amounted to only 10% in C57BL/6 offspring (comparable to B6D2F1crossings). Transgene methylation patterns were not detectably influenced by the parent-of-origin.
Unusual Clinical Findings in Prader-Willi Syndrome Patients with Uniparental Disomy
Authors: Schulze A. , Petersen M.B. , Horn N. , Kastrup K.W. , Brøndum-Nielsen K.
Published: July 2016

Eight patients with Prader-Willi syndrome (PWS), 3 males and 5 females, who were shown to have uniparental maternal disomy after investigation with polymorphic DNA marker spanning chromosome 15, were investigated clinically.

Four patients displayed in addition to the clinical signs, some unusual clinical feature: two patients showed a hairshaft anomaly, one of whom, a female, suggested a Menkes'-like condition-an investigation of copper uptake showed slightly increased values. Further investigations are in progress. One patient died unexpectedly at the age of 1 year 4 months and adenovirus was isolated postmortem in the airway secretion. Two patients presented a seizure disorder.

The mean birth weight was 2,122 (1,195-3,170) g and the gestational age was 37.1 (32-42) weeks for this group, lower than expected for PWS. Mean maternal age was elevated [31.9 (25-39) year].

Since the recent report [1] of a case of Bloom syndrome in a PWS patient led to the mapping of the Bloom syndrome gene to chromosome 15, it has been suggested that isodisomy could lead to homozygosity for recessive genes. This opens up the possibility of mapping genes in a new way. We suggest that uniparental disomy PWS patients should be investigated for unusual features to identify other monogenic disorders with a locus on chromosome 15. Isodisomy defined by multiple DNA markers indicates potential regions of candidate genes.
Absence of Genomic Imprinting at the DiGeorge Locus
Authors: Theophile D. , Bérubé D. , Augé J. , Vekemans M.
Published: July 2016

Fluorescence in situ hybridization (FISH) has been used to visualize specific genomic DNA sequences in interphase nuclei. Timing of replication can be measured by FISH to interphase nuclei: nuclei with a sequence that has not replicated reveal two single signals (G1), whereas those in which the sequence has replicated show two signal doublets (G2). Asynchronous nuclei show a single signal on one allele and a double hybridization dot on the other homologue. In general, most sequences replicate synchronously on the two homologues, with only 10% of nuclei showing an asynchronous hybridization pattern. However, for the sequences known about to be imprinted, approximately 30% of nuclei reveal asynchronous replication. Little is known whether or not the proximal region of chromosome 22, involved in the DiGeorge syndrome [1], is imprinted. We have, therefore, examined the replication timing pattern of the DiGeorge critical region (DGCR).
Fingernail, as an Alternative Source of DNA for Forensic Investigations and Medical Diagnostics A new technique to obtain template DNA in critical situations
Authors: Ricci U. , Uzielli M.L. Giovannucci
Published: July 2016

The use of PCR (polymerase chain reaction) is having a profound impact on forensic science and medical diagnostics.

Limited amounts of biological material and/or degraded low molecular weight DNA can be anticipated for forensic identification and often also for diagnostic investigations in fetuses, stillbirths and children with birth defects.

In vitro amplification of DNA, via PCR, represents an important tool for overcoming some of the limitations. Nevertheless, the problem of availability of biological samples as DNA source is often critic.

In order to obtain a useful and rapid procedure of DNA analysis in such difficult situations, we have recently developed a simple DNA extraction method using Chelex 100 and a PCR based amplification technique, and using fingernail as an alternative source of DNA.

Chelex 100 procedures result in denaturated DNA samples, not suitable for RFLPS analysis. Nevertheless we demonstrated that no differences are detectable between the genotypes obtained by PCR amplification using the conventional phenol-chlorophorm or saline extraction and the Chelex based procedure.

A DNA sample of 3-5 micrograms weight was easily obtained from fingernail clippings, and enabled us to perform several tests by using DNA typing methodologies, both for personal identification (in various forensic, medical and social situations) and in disputed parentage.

Our laboratory uses as polymorphic markers a set of several VNTRs (variable number of tandem repeats) and, more recently, a series of unlinked STRs (short tandem repeats). The use of DNA typing with STR loci provides an accurate, highly sensitive and rapid assay for parentage testing, forensic identification and medical applications.
Slow Twin Conception at First Birth and Subsequent Maternal Twin Proneness in a Natural Fertility Population
Authors: Nonaka K. , Desjardins B. , Charbonneau H. , Légaré J. , Miura T.
Published: July 2016

To study whether apparently more fecund women having delivered twins at first birth have traits of higher twin-proneness, we performed a retrospective cohort study on population-based historical vital records of the 17-18th century French Canadian immigrants and their descendants under natural fertility conditions. Among 24896 mothers who had at least one child, 248 had twin maternities at their first birth (twinning rate = 1.0%). Among 21508 mothers with a valid marriage-first birth interval, twinning rate was 0.97% among prompt conceptions (7.0-11.0 months), with a particularly high rate at the interval of 7.0-8.0 months (2.2%). Marriages in August-October resulted in a higher twinning rate particularly for the slow conceptions than those in the other seasons. Promptly-conceived mothers of twins at the first delivery may seem to have higher fecundity, but subsequent births from these mothers (n = 88) show a lower twinning rate (1.7%) particularly at younger maternal age than from the other mothers who had slowly conceived twins at their first birth (n = 112). The latter show a 4.5% twinning rate as a whole among their second or later births. So-called twin-proneness of a mother, whether genetic or acquired, was not connected to higher conception rate of twin's mothers immediately after marriage. Reduced fecundity, which may have been imposed by some environmental factors, could raise the chance of twinning.
Use of Single- and Multi-Locus and Polymerase Chain Reaction Systems for Zygosity Determination - Clinical Application in Twins with Clefts of the Lip and Palate
Authors: Eufinger H. , Rand S.P. , Schütte U.
Published: July 2016

Precision of zygosity determination in twins can be improved by the use of modern methods of DNA analysis. The clinical application of 4 single- (SLS) and 2 multi-locus (MLS), and 6 PCR (polymerase chain reaction) systems for zygosity determination in 12 twin pairs with oral clefts was compared with regard to the quality and quantity of sample material required and the probability of error in monozygosity determination. PCR systems proved to be superior to SLS or MLS, as DNA sampling is much more convenient, while its level of accuracy still fulfils clinical requirements. For this reason, PCR systems should be considered a basic method in modern clinical twin research.
Analysis of the Effect of Hormones on Opposite-Sex Twin Attitudes
Authors: Miller E.M. , Martin N.
Published: July 2016

Numerous reports in the literature suggest that hormones may transfer from one fetus to another, in humans as in animals. In a large sample of over seven thousand Australian adult twins, it was found that opposite-sex females showed a statistically significant tendency to hold more masculine attitudes than did same-sex female twins. This may be due to post-natal social interaction, but could also be caused by the transfer of testosterone from the male to the female fetus in opposite-sex twins.
Discordant Twin Pairs: The Relation Between Gestational Age and Neonatal Temperament Differences in Cotwins
Authors: Riese M.L.
Published: July 2016

Temperament differences between cotwins at least 15% discordant for birth-weight were compared for a group of 66 preterm twin pairs and a group of 70 fullterm twin pairs, assessed in the neonatal period. The assessment focused on irritability, resistance to soothing, activity, reactivity, and reinforcement value. For the most part, significant differences were not obtained between discordant preterm cotwins. Previous research [10] had demonstrated that the larger fullterm twin of discordant pairs was more irritable, more difficult to soothe, more active while awake and during sleep, less reactive to visual and auditory stimuli, and less reinforcing to the examiner than the smaller cotwin. It was concluded that, for the behavioral variables measured, the fullterm group is at higher risk than the preterm group, and that both the lighter and the heavier discordant twins displayed signs of early behavioral risk. The findings suggested that the continued gestation for cotwins discordant in weight may be a risk period for early temperament development of the twins.
The Epidemiology of Genetic Epidemiology
Authors: Hopper J.L.
Published: July 2016

Familial aggregation for disease is important; strong familial risk factors must exist even if the increased risk to a relative of an affected individual is modest. It is in practice difficult, however, to conduct studies in genetic epidemiology which conform to strict epidemiological principles. For twin studies there are two major questions: Are twins ‘no different’ from the population on which inference is to be made? Are study twins ‘no different’ to twins in the population? The importance of each question of bias depends on the scientific question, the trait(s) studied, and sampling issues. The strength of the twin design is its ability to refute the null hypothesis that genetic factors do not explain variation in a trait. Following the Popperian paradigm, alternate hypotheses should be considered in depth (both theoretically and empirically), with a design and sample size sufficient to exclude not just naive explanations. More sophisticated statistical techniques are now being applied, so the philosophy, assumptions, and limitations of statistical modelling must be appreciated. The concept of ‘heritability’ has, in the past, been misunderstood and misused. New advances in DNA technology promise to revolutionise epidemiological thinking, and so case-control-pedigree designs may well become standard tools. The strengths and limitations of studies based on related individuals as the sampling unit are discussed.
The Effects of Two EFL (English as a Foreign Language) Teaching Approaches Studied by the Cotwin Control Method: A Comparative Study of the Communicative and the Grammatical Approaches
Authors: Ando J.
Published: July 2016

The present study compared two different types of English-language teaching approaches, the grammatical approach (GA) and the communicative approach (CA), by the cotwin control method. This study has two purposes: to study the effects of teaching approaches and to estimate genetic influences upon learning aptitudes. Seven pairs of identical twins (MZ) and 4 pairs of fraternal twins (DZ) participated in the experiment along with 68 other nontwin fifth graders. Each cotwin was assigned to the GA and CA respectively and received 20 hours of lessons over a 10-day period. The behavioral similarities between MZ cotwins were statistically and descriptively depicted. No major effect of either teaching approach was noted, but the genetic influence upon individual differences of learning achievement was obvious. Furthermore, an interesting interaction between the teaching approaches and intelligence was found, that is, that the GA capitalises on and CA compensates for intelligence. This interactional pattern could be interpreted as an example of genotype-environment interaction. The relationship between genetic factors and learning aptitudes is discussed.
A Study of Maternity Provision in the UK in Response to the Needs of Families Who Have a Multiple Birth
Authors: Spillman J.R.
Published: July 2016

Multiple pregnancy is NEVER planned. A few years ago one could categorically make such a statement. Perhaps nowadays one cannot be so sure. Although parents are still unlikely to be able to plan such an event, it does seem that current infertility treatments may allow or even encourage practitioners to use methods which predispose to a multiple pregnancy. The practice of returning several fertilised embryos to the uterus in the hope of achieving a successful result has meant that many parents who longed for a baby have had to adjust to the realisation of a multiple pregnancy with all the effects such an occurrence has on family physical, social and emotional resources.

The Study of Triplets and Higher Order Births by the Office of Population Censuses and Surveys [1] highlighted the striking increase in Multiple Births in recent years. This was particularly evident in the case of triplets and higher order births. (Fig. 1) Care of these high-risk infants is costly in resources and no increased funding has been given to the National Health Service or Social Services budgets to provide care and support for the families.

This study endeavours to ascertain the needs of such families preconceptually, antenatally, intra-partum, postnatally and in the early months following the birth. It also tries to assess how appropriate current practice is in meeting these needs.
Delayed Interval Delivery of Two Remaining Fetuses in Quintuplet Pregnancy After Embryo Reduction: Report and Review of the Literature
Authors: de Jong M.W. , van Lingen R.A. , Wildschut J. , van Eijck J.
Published: July 2016

A case report is presented with a prolonged interval between delivery of 25 days. A quintuplet pregnancy resulted from hormonal stimulation of ovulation. Two fetuses remained after an embryo reduction was performed at 11 weeks gestation. At 22.5 weeks gestation the first twin (310 g) was delivered after spontaneous rupture of membranes. Using tocolytic agents, the second twin (710 g) was born at 26 weeks of gestation. This case is discussed and a review of the literature is given.
Influence of Clinical Variables on Triplet Birth Weight
Authors: Newman R.B. , Jones J.S. , Miller M.C.
Published: July 2016

The small size of most reported triplet series has resulted in conflicting statements about the influence of several clinical variables on triplet birth weight. Therefore, obstetrical and neonatal data were collected on 196 mothers and their 580 infants (8 stillbirths excluded). Gestational age was based on the date of fertilization in 13 IVF triplets and on the date of ovulation in 90 medically induced triplets. Obstetrical and ultrasonic criteria were used to estimate the date of confinement in 93 spontaneous triplets. Birth weight appeared to be higher in males and with higher maternal parity, independent of gestational age. The apparent effect of medical technologies such as ovulation induction or IVF on combined triplet birth weight disappeared when maternal parity and fetal gender were controlled. Preeclampsia, maternal race and zygosity were not significantly associated with birth weight. While birth order did not significantly effect ultimate birth weight, the heaviest triplet did present first more often than would be expected by chance alone. Future evaluation of neonatal outcome data in multifetal gestations should control for gestational age, fetal gender and maternal parity. It appears that triplet birth weight is not affected by etiology, which is important given the significant impact of medical technologies.
Time Trends in Characteristics and Outcome of Twin Pregnancies
Authors: Moreault L. , Marcoux S. , Fabia J. , Tennina S.
Published: July 2016

This study describes the evolution in fetal and neonatal mortality rates among twin pairs born in 22 hospitals located in the eastern regions of the province of Quebec in 1976-1978 (n = 776 pairs) and 1982-1985 (n = 712 pairs). It also assesses the contribution of maternal factors, obstetrical care and characteristics of twins in the variation of the risk of death over time. The fetal mortality rate did not improve from 1976-1978 (22.6 per 1000) to 1982-1985 (28.1 per 1000). However, the neonatal mortality rate declined from 44.7 to 34.7 per 1000 liveborn first twins and from 56.8 to 36.1 per 1000 liveborn second twins. For first twins as for second twins, birthweight-specific neonatal mortality rates decreased within birth weight categories under 2500 g. In the second period, 96.9% of twin pregnancies were detected before confinement compared to 59.6% in the earlier period. The proportion of twins delivered by obstetricians, the percentage of twin births occurring in ultraspecialized perinatal units and the frequency of caesarean sections increased markedly. The proportion of preterm births increased over time (34.5% vs 43.1%) whereas the percentage of low birthweight twins decreased but not significantly (54.3% 51.6%). In this study, changes in maternal age, parity, educational level, sex of pairs, qualification of the physician, and level of care available at the hospital of birth, did not account for the decrease in neonatal mortality rates among twins. The increase in the frequency of caesarean sections seemed to explain only a small proportion of the decrease in the neonatal mortality rate among second twins. In the second as well as in the first period, the neonatal mortality rate for twins was six times higher than that for singletons.
Factors Associated with Neonatal Problems in Twin Gestations
Authors: Fraser D. , Picard R. , Picard E.
Published: July 2016

We examined the neonatal outcome of 644 twins weighing 500 g or more and 656 singletons, born in the years 1984-1986 in the Soroka Medical Center, Beer-Sheva, Israel. There was nearly a four-fold risk of antepartum death in twins vs singletons, which disappeared when birth weight was controlled for. The risks for intrapartum and early neonatal mortality were not raised in this population. A statistically significant relative risk for congenital heart malformations in twins vs singletons remained (RR = 5.0, 95% CI = 1.5-16.3), after controlling for maternal age. Significantly higher rates of hyalin membrane disease, hypoglycemia, hyperbilirubinemia, anemia and septicemia were found in twins. Controlling for the confounding of the association between twinning and mortality or morbidity caused by differences in distributions of mode of delivery or gestational age between twins and singletons, was not as efficient as the controlling for birth weight. Thus, adjustment for birth weight removed all the excess risks detected except in hypoglycemia. Our findings suggest that the-lower birth weight of twins, which is so intimately associated with multiple gestations, is probably the single most important factor associated with neonatal problems found in twin births.
Recurrent Spontaneous Twinning
Authors: Blickstein I. , Borenstein R.
Published: July 2016

The perinatal outcome of seven recurrent twin deliveries after 28 weeks gestation, was compared to the first twin delivery and to randomly selected controls matched for parity, maternal age and gestational age. The outcome of the recurrent twin gestation was associated with significantly increased gestational age (P < 0.04) and mean twin birth weight (P < 0.05) compared to the first twin pregnancy. When compared to controls matched for maternal age and gestational age they were of significantly higher parity (P < 0.005) but had otherwise similar obstetric characteristics as when compared to controls matched for parity. These data suggest a better outcome for the recurrent compared to the first twin gestation. The frequencies of repeat twinning (0.0165% of all deliveries) and the calculated probability of having by chance a recurrent twin delivery were significantly different (P < 10−6) suggesting that both deliveries may be stochastically dependent events.
Congenital Anomalies in Twins in Northern Ireland. II: Neural Tube Defects, 1974-1979
Authors: Little J. , Nevin N.C.
Published: July 2016

In a large population-based study in Northern Ireland during the period 1974-1979, the rate of anencephalus in twins (9.1/10,000) was found to be less than that in singletons (24.3/10,000). This finding is in contrast with most other studies and the possibility of underascertainment of twin cases is considered, but it is concluded that chance is the likeliest explanation. The rate of spina bifida in twins (36.4/10,000) was similar to that in singletons (31.9/10,000). All of the twins with anencephalus were female and from pairs of like sex. Rates of spina bifida in twins from pairs of the two sex types were similar but, unusually, there was a male preponderance. As in previous studies, the great majority of twins with NTDs had unaffected cotwins.
Maternal Alcohol and Pentazocine Abuse: Neonatal Behavior and Morphology in an Opposite-Sex Twin Pair
Authors: Riese Marilyn L.
Published: July 2016

A pair of preterm, opposite-sex twins were examined during the lying-in period for behavioral and morphological effects of maternal alcohol and pentazocine abuse during pregnancy. A few morphological features typical of fetal alcohol syndrome were observed in each infant, and the male infant only was above the standardized mean in minor physical anomalies. The male's behavioral scores were more likely to be deviant from the standardized mean than the female's. Specifically, the male was more irritable, both spontaneously and in response to specific stimuli; highly active while awake and handled for the presentation of stimuli; more active than average during sleep; and low on ratings that reflect the attitude of the examiner toward the infant. These findings imply individual and gender differences in behavioral susceptibility to teratogens.
Structural Congenital Defects in Multiple Births
Authors: Mastroiacovo P. , Botto L.
Published: July 2016

The prevalence of twinning and higher order multiple births is high and is increasing in many countries, due at least in part to fertility-enhancing medical therapies. About 1 in 40-45 births is a twin; it is thus important to investigate whether the twinning status confers a higher risk for morbidity and mortality, particularly early in life. Birth defects are a major cause of morbidity and mortality in the pediatric age-group. The purpose of this review is to consider the evidence for an increased risk of some birth defects associated with twinning, using data from the literature and the Italian Multicentre Birth Defects Registry (IPIMC), to illustrate some of the challenging aspects of the study of birth defects in twins, and to suggest some guidelines for future investigations.

Twins are a heterogeneous group. They may differ in origin and genetic similarity, as for monozygotic (MZ) and dizygotic (DZ) twins; and in placentation (monochorial monoamniotic, monochorial diamniotic, dichorial with separate or fused placentae). Likewise, birth defects are known to be heterogeneous in presentation, pathogenesis, and etiology. Thus, the question raised here is not whether or not birth defects ‘in general’ are more common in twins, but rather whether or not there are any specific types of defects that are more frequent among specific types of twins. To maintain the generality of the discussion, this review will focus on those structural defects which are not unique to twins; conjoined twins and arcadia, defects which are unique to the twinning process, will not be discussed.
Studio Epidemiologico del Nato da Gravidanza Plurima
Authors: Cianciulli D. , Pezzati M. , Carbone C. , Mainardi G. , Panero C. , Biagioli-Cosenza E. , Biadaioli R. , La Torre A.
Published: July 2016

La gravidanza gemellare è stata sempre considerata «a rischio» come dimostrato dalla elevata incidenza di mortalità e morbosità. L'entità del rischio è stata valutata con una indagine statistica condotta sui nati nel periodo 1987-1993 nella U.O. di Neonatologia annessa alla Clinica Ostetrico-Ginecologica dell'Università di Firenze. Vengono riferiti i risultati di uno studio relativo all'incidenza di patologia in 463 gemelli confrontata con quella osservata in 15,658 nati da parto singolo. L'incidenza della gemellarità è stata del 2.87% (la media nazionale si aggira intorno al 2%). L'età gestazionale media dei gemelli oscilla intorno alle 35 settimane. Il 38% dei gemelli presenta un peso alla nascita ≥ 2,500g. rispetto al 94% dei singoli; il 12% dei gemelli è nato con peso < 1,500g. rispetto all'1.5% dei singoli. Il basso peso dei gemelli alla nascita è il risultato della prematurità e del ritardo di accrescimento. L'evento malformativp nella nostra U.O. è stato del 2.98% nelle gravidanze singole e del 5.61% nelle gravidanze plurime. La mortalità neonatale precoce è stata del 4.89% nei gemelli contro lo 0.46% nei singoli. La mortalità perinatale è stata del 7.77% nei gemelli contro l'1.15% nei singoli. La patologia respiratoria ha inciso nel parto singolo per il 2.31% e nel parto plurimo per il 4.96%. I risultati della nostra indagine sono stati discussi e confrontati con quelli della letteratura.
Indagine Parallels Familiare e Gemellare nella Psoriasi
Authors: Cavalieri R.
Published: July 2016

La Psoriasi è una dermatosi nota e chiara da diagnosticare con incidenza in ogni popolo e in molte famiglie molto elevata, pur con variabilità clinica notevole. La sua ereditarietà è incontestabile, pur tuttavia profonda è l'incertezza per quanto riguarda i vari parametri della sua ereditabilità. Le cause di ciò possono essere giustificate dalla totale variabilità di chnicizzazione in ogni soggetto psoriasico che va dai primi giorni di vita a oltre gli 80 anni.

Inoltre trattandosi di malattia dell'uomo ogni sperimentazione è inibita. Solo l'indagine gemellare può figurare come una sperimentazione in natura. Per rendere più veritiera possibile l'indagine su questo argomento, occorrono quindi osservazioni dirette su cifre molto elevate di questi malati.

A questo scopo abbiamo portato la nostra osservazione su:

– 8,000 casi di psoriasi

– 655 alberi genealogici di famiglie con almeno un caso di psoriasi, studiate almeno per tre generazioni.

In parallelo si è svolta l'osservazione su coppie gemellari consultando 10,000 coppie di gemelli (gemelloteca dell'Istituto Mendel). Sono state recepite 2,000 risposte dalle quali si evince che coppie di gemelli con psoriasi risultano almeno n. 26. Da notare che le coppie da noi esaminate erano sempre molto giovani. L'indagine popolazionistica nota in tutto il mondo varia da 1% a 2%. Da notare che ogni popolo anche di colore ne è colpito, ma in modo molto differenziato. Dalla nostra casistica evinta da un Centro di ampia consultazione, risulta che in Italia la dermatosi incide nello 0.9% fra tutta la popolazione. Tra i dermopazienti l'incidenza raggiunge 1'8%.
“Silent” Patent Ductus Arteriosus and Bronchopulmonary Dysplasia in Low-Birthweight Twins
Authors: Zanardo V. , Trevisanuto D. , Dani C. , Milanesi O. , Guglielmi A. , Cantarutti F.
Published: July 2016

During a screening protocol of early echocardiographic diagnosis (ATL MK 600) and treatment of “silent” PDA in RDS preterms with BW ≤ 1.750 kg, clinical data on premature twins were collected, including diagnosis of both PDA and BPD, to investigate whether twin birth influences PDA incidence and BPD development. Out of the 290 RDS preterms evaluated, 96 (33%) showed evidence of PDA, and a total of 79 (27%) developed BPD, 47 (16%) with associated PDA and 32 (11%) without PDA. Out of 238 singletons, 74 (31%) presented “silent” PDA and a total of 75 (31%) developed BPD, 44 (18%) with associated PDA, and 31 (13%) without PDA. In 52 other twins (18% of the total number of babies studied), 22 (42% of this subgroup) presented evidence of “silent” PDA, and 4 (8% of the subgroup), developed BPD, 3 with associated PDA (6% of the subgroup), and 1 without PDA (2% of the subgroup). From these data, it is inferred that that low-birthweight twins are at high risk for PDA hemodynamic complications during RDS, and may benefit from early induced ductal closure. Instead, in RDS twins, BPD was statistically less frequent (at the 99% C.L.) probably because twinning enhances fetal lung maturity, influencing enzymatic and nonenzymatic protective systems of lung defence.
An Italian Army Twin Register
Authors: Gedda L. , Messinetti S. , Brenci G. , Ronzani G.
Published: July 2016

Since military service in Italy is obligatory for all 20-year olds (“conscripts”) who do not choose to perform alternative civilian service, we thought of utilizing the data derived from the examinations all conscripts undergo, and selecting information relative to twins. The material we have gathered from the country's Draft Boards concerns the period from October 1987 to December 1988, and this information allows to determine: 1) the twin status of a conscript and the identification of his cotwin; 2) aptitude for military service; 3) occupation; 4) presence of twins in the father's or mother's lineage; 5) home address and telephone number.

The twin material collected concerns 2,739 male pairs and 1,433 pairs of both sexes, classified with respect to:

1) Aptitude for military service;

2) Choice of occupation;

3) Presence of twins in the family.
Genetic Variance and Heritability of Temperament Among Chinese Twin Infants
Authors: Chen C.J. , Yu M.W. , Wang C.J. , Tong S.L. , Tien M. , Lee T.Y. , Lue H.C. , Huang F.Y. , Lan C.C. , Yang K.H. , Wang H.C. , Shih H.Y. , Liu C.Y. , Chen J.S.
Published: July 2016

In order to examine the genetic variance and heritability of temperament among Chinese infants in Taiwan, a total of 62 pairs of same-sexed twin infants given birth in four major general teaching hospitals in Taipei City were studied. Based on placentation and 12 red blood cell antigens, 44 MZ and 18 DZ pairs were identified. Temperament was assessed at the age of six months by the Chinese edition of Carey's Temperament scale. Significant genetic variance was observed for activity level, approach or withdrawal, intensity of reaction, quality of mood, and threshold of responsiveness, with a heritability of 0.64, 0.56, 0.74, 0.39, and 0.45, respectively. There was no significant intrapair difference in temperamental characteristics between monochorionic and dichorionic MZ twins.
An Examination of the Psychological and Behavioural Factors in the Development of Language Retardation in Twins
Authors: Sandbank A.C. , Brown G.A.
Published: July 2016

Using therapeutic intervention, the psychological and behavioural factors in the development of language retardation in two pairs of 4-year-old MZ twins have been examined. Although some factors are common to those found in singletons with language retardation, the factors peculiar to the twin situation are highlighted.
Raising Twin Babies and Problems in the Family
Authors: Chang C.
Published: July 2016

Out of 296 mothers of twins interviewed about difficulties encountered while rearing twins, 49% mentioned inadequate sleep, 18% financial strain, 39% emotional disturbance, 22% disturbance in the marital relationship, and 43% lack of time to take care of other children. With the growth of twins, the problems gradually decreased, except for emotional disturbance, the most difficult period being the first year. Only 15% reported leaving the babies in the care of relatives during the day time. Overall, 68.2% felt the support from the father, but 39% of them felt the support was useless; 49% felt support from the mother-in-law, but 43% of them regarded the mother-in-law to be of no help; 36% were supported by their own mothers, but 54% mentioned that they had received little help. One must conclude that social support from relatives was inadequate. Public policy should take this fact into account and provide public health nurses and social workers to help the mothers of twins, especially during the first year.
Temperament and Neonatal Risk in Full-Term and Preterm Combined Vaginal/Cesarean Section Twin Pairs
Authors: Riese M.L.
Published: July 2016

Ten pairs of full-term and 8 pairs of preterm twins from combined vaginal and Cesarean section deliveries were evaluated on measures of neonatal temperament, developmental status, and integrity to determine if the Cesarean-delivered infant was compromised relative to its vaginally-delivered twin. There were no significant differences, within groups, between the vaginal and Cesarean section infants on measures of risk and developmental status. Analyses of variance of paired comparisons performed on the temperament measures indicated that, for the full-term group, there were no significant differences in ratings between vaginally and Cesarean-delivered infants. In contrast, preterm infants delivered by Cesarean section were more active during sleep than their vaginally-delivered cotwins. This finding, together with previous findings demonstrating a relation between this measure and temperament at 9, 18, and 24 months of age, suggested that the preterm Cesarean-delivered infant may be at risk in this area when compared with its twin. In the main, however, the results demonstrated that infants born by Cesarean section following vaginal delivery of their twins were not more compromised than their twin siblings.
Frequency of Triplets and Triplet Zygosity Types among U.S. Births, 1964
Authors: Allen Gordon
Published: July 2016

The frequency of triplets in the U.S. white population may have reached an all-time low around 1964, at 78 sets per million deliveries. One-fourth of those were monozygotic as estimated by the difference method, or 18% by Bulmer's theoretical model. By 1983 the frequency of triplets had nearly doubled, the increase presumably occurring in dizygotic and trizygotic types. In Belgium most triplet pregnancies now result from artificial induction of ovulation, which is expected to occur mainly in older mothers. In the U.S., however, triplets have increased as much in young mothers as in older mothers, proportionally. This age distribution of the increase may be partly explained by a decrease in parity in older mothers since 1964.
Fertility, Fecundity and Twinning: A Comparison of the Trends in Births and Twinning in Australia from 1854 to 1982
Authors: Doherty John D.H.
Published: July 2016

The trends in births and in twinning in Australia are compared from 1854 to 1982. Until about 1930 the twinning rate increased as births fell. The two rates then became concordant. The relationship of fecundity to twinning is discussed. Comparison with other countries is made. The period embraces the demographic transition when changing contraceptive practices would have had a variable effect on twinning.
The Validity of Weinberg's Rule in the East Flanders Prospective Twin Survey (EFPTS)
Authors: Vlietinck R. , Derom C. , Derom R. , den Berghe H. Van , Thiery M.
Published: July 2016

Most population studies of twins estimate the number of monozygotic (MZ) and dizygotic (DZ) pairs by Weinberg's differential rule. This rule assumes that within the DZ twins the numbers of unlike-sexed (U) and like-sexed (L) twins are equal. The literature on the validity of Weinberg's rule is still controversial. In this prospective population-based study (EFPTS) of 2,589 twin pairs, of whom 2,577 were of known zygosity and placentation, the estimates of Weinberg's rule agree well with the results of direct zygosity determination.
Maternal Recognition of Twin Pregnancy
Authors: Malmstrom P.E.M. , Malmstrom E.J.
Published: July 2016

In a retrospective survey of 336 mothers of recently born multiples, 71% reported suspicions of twin pregnancy prior to medical confirmation. Primiparous and multiparous reports of symptoms may be utilized to significantly increase the early diagnosis of the presence of multiples.