bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of sonographic estimates of fetal weight in very small infants
Authors: Kaaij M. W. , Struijk P. C. , Lotgering F. K.
Published: March 2003

Objective

Fetal outcome is inversely related to gestational age and birth weight. Therefore, in very small fetuses, estimated weight may play an important role in clinical management. Our aim was to determine the accuracy of sonographic estimates of fetal weight in very small infants.

Design

Retrospective chart review.

Subjects

We retrospectively studied 100 consecutive infants with a birth weight of < 1000 g, at a gestational age between 24.0 and 34.0 weeks, in which biometric data < 2 weeks prior to delivery were available for analysis.

Methods

We estimated fetal weight with the use of two methods ‐ by those of Hadlock and colleagues3 and Scott and colleagues4 ‐ and compared the estimated values with measured birth weights.

Results

The infants had a mean birth weight of 742 ± 173 (SD) g, at a gestational age of 28.1 ± 2.0 (SD) weeks. With Hadlock's method, the mean estimated fetal weight (EFW) was 736 ± 186 (SD) g, which was not significantly different from birth weight; the mean EFW error was 0.8 ± 12.7 (SD) %. With Scott's method, the mean EFW was 780 ± 185 (SD) g, which was significantly increased above birth weight; the mean EFW error was 5.7 ± 12.5 (SD) %. The accuracy of the weight estimates was not significantly affected by the period between ultrasound examination and delivery if < 2 weeks, or by fetal growth restriction.

Conclusion

In our population of small fetuses, Hadlock's estimates of fetal weight correlated well with measured birth weight, whereas Scott's method tended to overestimate. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Maternal age‐ and gestation‐specific risk for trisomy 21
Authors: Snijders R. J. M. , Sundberg K. , Holzgreve W. , Henry G. , Nicolaides K. H.
Published: March 2003

Objective

To provide estimates of maternal age‐ and gestational age‐related risks for trisomy 21.

Methods

The prevalence of trisomy 21 was examined in 57 614 women who had fetal karyotyping at 9–16 weeks of gestation for the sole indication of maternal age of 35 years or more. On the basis of the maternal age distribution and the reported maternal age‐related risk for trisomy 21 at birth, the expected number of trisomy 21 cases was calculated for each gestational age subgroup (9–10 weeks, 11–14 weeks and 15–16 weeks). The ratio of the observed to expected number of cases of trisomy 21 was then calculated and regression analysis was applied to derive a smoothened curve. The formula for maternal age‐ and gestational age‐related risk was then applied to a population of 96 127 pregnancies that were examined at 10–14 weeks to calculate the expected number of trisomy 21 pregnancies, and this number was compared to the observed number of 326.

Results

In the 57 614 pregnancies there were 538 cases of trisomy 21. The relative prevalences of trisomy 21, compared to a prevalence of 1.0 at 40 weeks, was 10 exp(0.2718 × log10(gestation)2 − 1.023 × log10(gestation) + 0.9425). On the basis of the estimated maternal age‐ and gestational age‐related risks, the expected number of trisomy 21 cases at 10–14 weeks of gestation in the 96 127 pregnancies was 329 (95% confidence interval 291–361), which was not significantly different from the observed number of 326 cases (χ2 = 0.02).

Conclusion

The risk for trisomy 21 increases with maternal age and decreases with gestation. The prevalence of trisomy 21 at 12 and 16 weeks of gestation is higher than the prevalence at 40 weeks by 30% and 21%, respectively. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
The ‘Mickey Mouse’ sign and the diagnosis of anencephaly in early pregnancy
Authors: Chatzipapas I. K. , Whitlow B. J. , Economides D. L.
Published: March 2003

Objectives

To assess the sonographic screening for anencephaly in the first trimester in a low‐risk obstetric population.

Methods

Since 1994, 5388 women attended our clinic for a first‐trimester scan (11–14 weeks of gestation) and screening for structural and chromosomal abnormalities. The patients underwent transabdominal scanning, and transvaginal scanning if necessary.

Results

The ultrasonographic appearances of anencephaly in the first trimester are different from the familiar second‐trimester signs. The cerebral hemispheres are present and exposed to the surrounding amniotic fluid. The ultrasound appearances in the coronal section of the head are best described as ‘Mickey Mouse face’. There were six cases of anencephaly (incidence 1.1 : 1000). All cases were diagnosed in the first trimester and five demonstrated this sign. There were no false‐positive diagnoses. The crown‐rump length was significantly reduced in all affected fetuses.

Conclusion

First‐trimester ultrasonographic diagnosis of anencephaly is accurate, but sonographers should be familiar with the ultrasound appearances that are different from those in the second trimester. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal sonographic features of embryonal rhabdomyosarcoma
Authors: Önderoğlu L. S. , Yücel A. , Yüce K.
Published: March 2003

We describe a case of fetal rhabdomyosarcoma detected during the third trimester of pregnancy by prenatal sonography. At 33 weeks' gestation, sonography performed because of suspected polyhydramnios showed a solid mass of 120 × 54 mm arising from the anterior wall of the fetal thoracic cage. Another mass within the left maxillary area which originated from the left orbital floor was also detected. In the abdomen, there were multiple round masses in and around the liver. As the previous scan at 28 weeks had appeared normal, the multiple masses which became visible and enlarged rapidly in different locations led us to believe that there was fetal cancer. The most likely diagnosis was rhabdomyosarcoma (which was later con‐firmed), because it is the most prevalent soft‐tissue tumor in children and may develop within or outside muscle anywhere in the body and at any age. Two other reported cases which were detected by prenatal ultrasound examination are also discussed. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
First‐trimester determination of fetal gender by ultrasound
Authors: Efrat Z. , Akinfenwa O. O. , Nicolaides K. H.
Published: March 2003

Objective

To assess the accuracy of fetal sex determination at 11–14 weeks of gestation.

Methods

Fetal gender assessment by ultrasound was prospectively carried out in 172 singleton pregnancies at 11–14 weeks of gestation immediately before chorionic villus sampling for karyotyping. The genital region was examined in a midsagittal plane and the fetal gender was assigned as male if the angle of the genital tubercle to a horizontal line through the lumbosacral skin surface was greater than 30° and female when the genital tubercle was parallel or convergent (less than 30°) to the horizontal line.

Results

The accuracy of sex determination increased with gestation from 70.3% at 11 weeks, to 98.7% at 12 weeks and 100% at 13 weeks. In the male fetuses, there was a significant increase in the angle of the genital tubercle from the horizontal with crown‐rump length. Male fetuses were wrongly assigned as female in 56% of cases at 11 weeks, 3% at 12 weeks and 0% at 13 weeks. In contrast, only 5% of the female fetuses at 11 weeks were incorrectly assigned as male and this false‐positive rate was 0% at 12 and 13 weeks.

Conclusion

The clinical value of determination of fetal sex by ultrasound is in deciding whether to carry out prenatal invasive testing in pregnancies at risk of sex‐linked genetic abnormalities, because invasive testing would be necessary only in pregnancies with male fetuses. Our results suggest that a final decision on invasive testing for sex‐linked conditions should be undertaken only after 12 weeks of gestation. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Sonographic evaluation of antepartum development of fetal gastric motility
Authors: Sase M. , Tamura H. , Ueda K. , Kato H.
Published: March 2003

Objective

Little is known about the development of fetal gastric motility and emptying. The aim of this study was to evaluate the development of gastric motility sonographically in the human fetus.

Methods

The motility and peristalsis of the fetal stomach were sonographically studied in 76 normal fetuses at 12–39 weeks of gestation. Fetal gastric motility was assessed by videotaping real‐time ultrasonic images of the stomach for periods of 60 or more minutes.

Results

Gastric peristalsis appeared as early as 14 weeks of gestation, and was detected in all fetuses by 23 weeks. The frequency of peristaltic waves was constant, and was 2.2–3 times per minute at 14–39 weeks of gestation. The onset of fetal gastric peristalsis was sporadic and the period with no peristaltic waves was dominant before 24 weeks of gestation. Fetal gastric peristalsis increased and consolidated into long‐term clusters from 24 weeks of gestation. The mean duration of peristalsis increased from 4.1 ± 1.2 min (n = 6) at 20–23 weeks to 14.1 ± 3.2 min (n = 14) at 32–35 weeks of gestation, and remained constant thereafter.

Conclusions

Fetal gastric motility was quantified and its development during pregnancy was assessed in this study. There was a critical point of development at around 24–25 weeks of gestation when grouped peristalsis was observed in all fetuses. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
First‐trimester ultrasound diagnosis of holoprosencephaly: three case reports
Authors: Wong H. S. , Lam Y. H. , Tang M. H. Y. , Cheung L. W. K. , Ng L. K. L. , Yan K. W.
Published: March 2003

We present three cases of fetal holoprosencephaly diagnosed by transabdominal and transvaginal ultrasound examinations at 10 and 13 weeks' gestation. The diagnosis was based on two sonographic criteria: first, the intracranial finding of a single ventricle with a cerebral mantle and no visible midline structures but fusion of the thalami and corpus striatum; and, second, facial abnormalities, including hypotelorism. The ultrasound findings were confirmed by embryoscopy before abortion in one case and by pathological examination after abortion in two cases. Chromosome study of the three fetuses showed trisomy 18, triploidy and mosaic 18p deletion and duplication. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Sonographic features of fetal trisomy 18 at 13 and 14 weeks: four case reports
Authors: Lam Y. H. , Tang M. H. Y.
Published: March 2003

Fetal trisomy 18 is the second most common multiple malformation syndrome. We present four cases of trisomy 18 with multiple sonographic abnormalities at 13 and 14 weeks of gestation. These cases demonstrated that fetal hand deformities can be a tell‐tale sign of trisomy 18 with or without increased nuchal translucency at this gestation. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal assessment of Wharton's jelly in umbilical cords with single artery
Authors: Raio L. , Ghezzi F. , Di Naro E. , Franchi M. , Brühwiler H. , Lüscher K. P.
Published: March 2003

Objective

To investigate whether the amount of Wharton's jelly in non‐malformed fetuses with a single umbilical artery is different from that of fetuses with a normal umbilical cord.

Methods

We evaluated patients with singleton pregnancies, non‐malformed fetuses and single umbilical artery undergoing sonographic evaluation at a gestational age ranging from 19 to 41 weeks' gestation. The cross‐sectional areas of the umbilical cord and of the umbilical vessels were measured. The amount of Wharton's jelly was calculated by subtracting from the total cross‐sectional area of the umbilical cord the areas of the artery and of the vein. The umbilical cord cross‐sectional area, the umbilical artery and vein areas as well as the amount of Wharton's jelly were plotted on previously published nomograms.

Results

Twenty‐two patients met the inclusion criteria. The umbilical cord cross‐sectional area was within the normal range in 20 (90.1%) cases. The umbilical artery and vein areas were above 2 standard deviations from the mean in 20 cases and in 11 cases (50%), respectively. The amount of Wharton's jelly was below 2 standard deviations from the mean in all cases. An abnormal insertion of the umbilical cord (marginal, velamentous) was present in five cases (22.7%).

Conclusions

A reduction of Wharton's jelly is frequently present in cases of single umbilical artery. The increased perinatal morbidity and mortality observed in cases of single umbilical artery, even in the absence of congenital or chromosomal abnormalities, could be in part the consequence of a reduced amount of Wharton's jelly. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Evaluation of cerebral perfusion pressure changes in laboring women: effects of epidural anesthesia
Authors: Williams K. P. , Wilson S.
Published: March 2003

Objective

To compare the effect of epidural anesthesia on cerebral perfusion pressure in laboring women.

Study

design Maternal cerebral blood flow velocity was assessed in seven laboring patients with continuous epidural anesthesia and 15 without, using transcranial Doppler. Maternal cerebral blood flow velocity was assessed during the first stage at the trough of a contraction, at the peak of a contraction and at the second stage during pushing over the course of four contractions. Calculated estimated cerebral perfusion pressure: eCPP = Vmean /(Vmean − Vdiastolic ) × (mean BP − diastolic BP), where V is velocity and BP is blood pressure; modified from Aaslid and colleagues. An index of cerebrovascular resistance, the resistance area product, was calculated: RAP = mean BP/mean velocity. We calculated an index of cerebral blood flow (cerebral blood flow index): CBF index = eCPP/RAP.

Results

In non‐epidural patients, the eCPP fell significantly at the peak of a contraction and during pushing. Cerebrovascular resistance, RAP, rose significantly during the peak of a contraction, although cerebral blood flow did not change. In patients undergoing epidural anesthesia, the stages of labor had no significant effect on eCPP or RAP; however, these values were lower than those in patients without epidural anesthesia.

Conclusions

The epidural group had a lower eCPP and RAP and cerebral blood flow index compared to the non‐epidural group. In the non‐epidural group, the mean arterial pressure was higher in all stages of labor with a trend towards an increase in eCPP and cerebral blood flow index. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
WS02: Prenatal diagnosis WS02‐01Sonographic measurement of fetal subcutaneous tissue of gestational diabetic mothers: a new criteria for therapy
Authors: Ferrazzi E. , Cetin I. , Rigano S. , Radaelli T. , Taricco E. , Bozzo M. , Lanzani C. , Pardi G.
Published: March 2003

Objective

The aim of this study was to compare sonographic measurements of subcutaneous tissue (SQ) in fetuses of gestational diabetic mothers (GDM), and in normal fetuses.

Methods

SQ was measured as the subcutaneous tissue area of mid upper arm (FMA), mid‐thigh (FMT) (cross sectional area minus bone and muscle area), abdominal (FA) and subscapular fat (FS), thickness. Fifty‐six GDM were enrolled in the study. Normal values were obtained from fetuses of normal pregnancies (BMI 21.3 ± 0.64 Kg/m2; one hour glucose test < 140 mg/dL) (30 patients). Treatment was based on diet alone, or diet plus insulin according to postprandial glicemia. Longitudinal ultrasound examinations were performed every four weeks, in normal pregnancies, and in GDM pregnancies.

Results

Fetal SQ measurements were significantly correlated to gestational age both in normal and GDM fetuses (P < 0.05). At the time of diagnosis GDM fetuses had significantly higher values for all SQ measurements compared to AGA fetuses; these differences were not found during therapy.

26–32 weeks diagnosis
32–36 weeks therapy

normal
GDM

normal
GDM
p

FA
0.32 ± 0.01
0.38 ± 0.01
Ns
0.45 ± 0.02
0.47 ± 0.02
0.001

FS
0.28 ± 0.01
0.36 ± 0.17
Ns
0.41 ± 0.36
0.44 ± 0.02
0.001

FMA
1.97 ± 0.12
2.55 ± 0.19
Ns
3.83 ± 0.33
4.24 ± 0.21
0.01

FMT
3.12 ± 0.20
4.10 ± 0.37
Ns
5.91 ± 0.42
6.94 ± 0.43
0.01

Conclusions

GDM is associated with increases in fetal SQ from the second trimester. A strict glycemic control can reduce these differences to negligible values. These new measurements can be adopted to monitor the efficacy of therapy in GDM pregnancies.
Fetal compensatory renal hypertrophy with a unilateral functioning kidney
Authors: Hill L.M. , Nowak A. , Hartle R. , Tush B.
Published: March 2003

Objective To evaluate the possibility of fetal compensatory renal hypertrophy with a unilateral functioning kidney.

Methods A nomogram of renal length was established from 254 normal fetuses. Renal length was also obtained in 14 fetuses with unilateral renal agenesis and 22 fetuses with a unilateral multicystic kidney.

Results Compensatory renal hypertrophy, defined as a renal length > 95th percentile for gestational age, occurred in 16 of 36 cases (44.4%).

Conclusions Compensatory renal hypertrophy is detectable in utero and may occur as early as 22 weeks' gestation.
Prenatal depiction of angioarchitecture of an aneurysm of the vein of Galen with three‐dimensional color power angiography
Authors: Lee T.‐H. , Shih J.‐C. , Peng S.S.‐F. , Lee C.‐N. , Shyu M.‐K. , Hsieh F.‐J.
Published: March 2003

A fetus with a large supratentorial cyst and cardiomegaly was encountered at 33 weeks of gestation. The cyst appeared as an aneurysmal, fluid‐filled structure extending posteriorly with a finger‐like appendage. Using color flow mapping, we disclosed rapid in‐and‐out blood flow with marked turbulence within the cyst. For evaluation of its blood supply and venous drainage of the vascular malformation, a three‐dimensional reconstruction of the power Doppler image was conducted. The results revealed that the vascular malformation was supplied by a small contralateral aneurysm from the branches of Willis' circle, draining posteriorly into an abnormal falcine sinus and then into the superior sagittal sinus. No other fetal abnormality such as hydrocephalus or hydrops was discovered. The prenatal diagnosis of an aneurysm of the vein of Galen was made on the basis of the gray‐scale, color Doppler findings, and also the angioarchitecture obtained by three‐dimensional power Doppler imaging. The woman was admitted at 37 weeks of gestation due to labor onset and delivered the baby via the vaginal route without complication. Postnatal angiography and magnetic resonance imaging confirmed the diagnosis of an aneurysm of the vein of Galen, and the angioarchitecture depicted it before birth. We suggest that three‐dimensional power Doppler ultrasonography may assist in the diagnosis of an aneurysm of the vein of Galen, and precisely delineate the complicated corresponding vasculature. This may guide postnatal management and predict the prognosis more accurately. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Blood flow velocity waveforms of the fetal pulmonary artery and the ductus arteriosus: reference ranges from 13 weeks to term
Authors: Mielke G. , Benda N.
Published: March 2003

Objective To establish reference ranges for blood flow velocity waveforms of the fetal main pulmonary artery and the ductus arteriosus during the second and third trimesters of pregnancy.

Methods A prospective cross‐sectional echocardiographic study was performed in 222 normal fetuses from 13 to 41 weeks of gestation using high resolution/color Doppler ultrasound equipment.

Results Gestational age‐specific reference ranges are given for peak velocity across the pulmonary valve, velocities in the ductus arteriosus, peak systolic velocity in the ductus arteriosus‐to‐peak velocity across the pulmonary valve ratio, ductal systolic velocity‐to‐diastolic velocity ratio, ductal resistance index and ductal pulsatility index. In the ductus arteriosus, increasing fetal heart rate was significantly associated with increasing end‐diastolic velocity and decreasing systolic‐to‐diastolic ratio, decreasing resistance index, and decreasing pulsatility index.

Conclusions Based on a prospective study in more than 200 normal fetuses, the data provide gestational age specific reference ranges for blood flow velocity waveforms of the fetal pulmonary artery and the ductus arteriosus. The reference ranges may be helpful in prenatal diagnosis of cardiac malformations and ductal obstruction from 13 to 41 weeks of gestation.
Cervical assessment at the routine 23‐weeks' scan: problems with transabdominal sonography
Authors: To M.S. , Skentou C. , Cicero S. , Nicolaides K.H.
Published: March 2003

Objectives

To compare transabdominal and transvaginal sonographic measurements of cervical length in pregnancy and examine the factors that may influence these measurements.

Methods

The study population consisted of 149 women with singleton pregnancies attending for routine ultrasound examination at 23 weeks of gestation. In all women the cervix was successfully visualized by transvaginal sonography and cervical length was measured after emptying of the bladder. This measurement was compared to that obtained by transabdominal sonography. In addition the ability to visualize the cervix transabdominally was examined in relation to body mass index (BMI), bladder volume and cervical length.

Results

The percentage of cases in which the cervix could be seen transabdominally increased from 42% for bladder volume of < 50 ml to 73% for volumes > 150 ml, and 13% for cervical length < 20 mm to 51% for lengths > 40 mm. The ability to visualize the cervix was unrelated to BMI. Although there was a significant association between measurements taken transabdominally with those made transvaginally, measurements taken with a full bladder were significantly longer than those with an empty bladder.

Conclusion

The aim of cervical assessment in pregnancy is to identify women with a short cervix because they are at high risk of preterm delivery. This aim can not be fulfilled by transabdominal sonography. Such a scan fails to visualize the cervix in a high proportion of cases and in particular those with a short cervix. Furthermore, successful visualization requires a full bladder which falsely increases cervical length. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal diagnosis of a subdural hematoma associated with reverse flow in the middle cerebral artery: case report and literature review
Authors: De Spirlet M. , Goffinet F. , Philippe H. J. , Bailly M. , Couderc S. , Nisand I.
Published: March 2003

To our knowledge this is the first reported case of a subdural hematoma, related to fetal autoimmune thrombocytopenia, diagnosed prenatally by ultrasound. The underlying etiology was hidden maternal autoimmune thrombocytopenia. This disease, which is as serious as alloimmune thrombocytopenia, causes severe fetal thrombocytopenia, which carries with it a high risk of intracranial hemorrhage and recurrence in subsequent pregnancies. Only 14 cases of fetal subdural hematomas have been reported in the literature. The etiologies of these cases were principally traumatic, or due to disorders of hemostasis. Their prognoses were generally poor, with 50% resulting in fetal death in utero and the remaining 50% demonstrating post‐natal sequelae. The presence of reverse flow in the middle cerebral artery is rare and its association with a subdural hematoma unusual. Abnormalities found on cerebral Doppler studies indicate an adaptive response to a fetal condition for which the prognosis is then very poor. Monitoring fetuses at risk for hemorrhage by ultrasound imaging and Doppler studies enables us to detect indicators of a worsening prognosis before the ultrasound appearance of morphological hemorrhage. The development of intracranial hemorrhage raises difficult management issues during the index pregnancy and in subsequent pregnancies. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Transabdominal sonography of the cavum septum pellucidum in normal fetuses in the second and third trimesters of pregnancy
Authors: Falco P. , Gabrielli S. , Visentin A. , Perolo A. , Pilu G. , Bovicelli L.
Published: March 2003

Objectives

To assess the visualization rate and size of the cavum septum pellucidum (CSP) by transabdominal sonography in normal fetuses throughout pregnancy.

Methods

The CSP was prospectively researched and measured using an axial transventricular plane in 286 consecutive uncomplicated singleton pregnancies between 15 and 41 weeks of gestation.

Results

The CSP was seen in 40% of cases at 15 weeks, 82% at 16–17 weeks, 100% at 18–37 weeks and 79% at 38–41 weeks. Compared to biparietal diameter (BPD), the visualization rate was 33% between 31 and 32 mm, 45% between 33 and 34 mm, 84% between 35 and 43 mm, 100% between 44 and 88 mm and 86% between 89 and 99 mm. Mean CSP width was 5.3 ± 1.7 mm (range 2–9 mm). The CSP width increased with gestational age and BPD but with a slight decrease around term.

Conclusions

In normal fetuses the CSP should always be visualized between 18 and 37 weeks, or with a BPD of 44–88 mm. Failure to observe the CSP in this interval, or possibly the presence of a large CSP, may indicate abnormal cerebral development and warrant further investigation. Conversely, absence of the CSP prior to 18 weeks, or later than 37 weeks, is a normal finding. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Early screening for fetal cardiac anomalies by transvaginal echocardiography in an unselected population: the role of operator experience
Authors: Rustico M. A. , Benettoni A. , D'Ottavio G. , Fischer‐Tamaro L. , Conoscenti G. C. , Meir Y. , Natale R. , Bussani R. , Mandruzzato G. P.
Published: March 2003

Objective

To examine the accuracy of early transvaginal fetal echocardiography performed in an unselected population by operators with different levels of experience and to compare the results with those obtained from a referral population.

Design

Prospective study.

Methods

A series of 4785 unselected fetuses and 221 referred fetuses were screened at 13–15 weeks' gestational age by transvaginal echocardiography. For each fetus, visualization of the four‐chamber view plus the origin of the great arteries was attempted. Color Doppler imaging was only performed in cases of cardiac malformations already identified by two‐dimensional echocardiography. The scans were performed by seven operators with different levels of experience. Reliability was assessed by conventional transabdominal echocardiography at 20–22 weeks, by postnatal follow‐up in the first 3 months of life, and/or by autopsy in all cases of termination or fetal death.

Results

The rate of complete visualization (four‐chamber view plus great arteries) was 47.5% in the unselected population, and 76.9% in the referral population. There were four (0.08%) true positives among the unselected fetuses, and five (2.3%) among referrals, mostly with enlarged nuchal translucency or other malformations. Among the unselected fetuses, nine false negatives were detected by transabdominal echocardiography. Improvement in the operators' ability to recognize cardiac anomalies in unselected population was disappointing and was influenced more by individual approach than by the number of examinations performed.

Conclusions

Early screening for cardiac anomalies among unselected fetuses is ill‐advisable. The usefulness of an early approach is confirmed in high risk fetuses or in the presence of enlarged nuchal translucency when performed by expert operators. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Cervical length at 23 weeks in triplets: prediction of spontaneous preterm delivery
Authors: To M.S. , Skentou C. , Cicero S. , Liao A.W. , Nicolaides K.H.
Published: March 2003

Objectives

To establish the distribution of cervical length at 23 weeks of gestation in triplet pregnancies and to examine the relation to preterm delivery before 33 weeks.

Methods

Cervical length was measured by transvaginal sonography at 23 (range 22–24) weeks of gestation in 43 triplet pregnancies. The distribution of cervical length was determined and the relationship between cervical length and the rate of spontaneous preterm delivery before 33 weeks was calculated.

Results

The cervical length distribution was skewed to the left with a median of 34 mm. The rate of spontaneous labor and delivery before 33 weeks increased exponentially with decreasing cervical length at 23 weeks from 8% at 36–48 mm, to 11% at 26–35 mm, 33% at 16–25 mm and 67% at 15 mm or less. Cervical length was ≤30 mm, ≤25 mm and ≤15 mm in 37%, 16% and 8% of cases, respectively, and the corresponding sensitivities in the prediction of spontaneous delivery before 33 weeks were 67%, 50% and 33%.

Conclusions

In triplet pregnancies, measurement of cervical length provides a useful prediction of risk for spontaneous early preterm delivery. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Color Doppler imaging of placental masses: differential diagnosis and fetal outcome
Authors: Prapas N. , Liang R.‐I. , Hunter D. , Copel J. A. , Lu L.‐C. , Pazkash V. , Mari G.
Published: March 2003

Objectives

To evaluate the application of Doppler imaging in the differential diagnosis of placental masses and perinatal outcome.

Methods

A retrospective study of all cases referred for suspicion of placental chorioangioma over a nine and a half year period. Only cases in which color flow mapping and pulsed Doppler examination were performed were considered.

Results

Fourteen cases fulfillled the criteria and included seven cases of chorioangioma, two cases of placental hemorrhage and five cases of a placental mass which resolved during pregnancy. All cases of chorioangioma could be distinguished by increased blood flow within the mass. Polyhydramnios was associated with six cases of chorioangioma. Rapid tumor growth, premature labor and neonatal death occurred in one case. Premature labor occurred in six cases of chorioangioma and both cases of placental hemorrhage. IUGR was associated with two cases of chorioangioma and both cases of placental hemorrhage. All cases of resolving placental mass delivered uneventfully at term.

Conclusions

Color Doppler is a useful tool in the differentiation of placental masses. Such masses should be followed up regularly because their growth rate is variable and unpredictable. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Fetal urine production and accuracy when estimating fetal urinary bladder volume
Authors: Fägerquist M. , Fägerquist U. , Odén A. , Blomberg S. G.
Published: March 2003

Objectives

The volume of the fetal urinary bladder can be estimated by measuring bladder diameters on an ultrasound image. The calculated urine production rate might reflect the fetal status in compromised pregnancies. The aim of this study was to assess the fetal urine production rate and the accuracy of measurements of diameters and volumes of the bladder.

Design

Urine production rate and the variability in volume measurement error were assessed by ultrasound examinations of fetal bladder images documented on videotapes. In material comprising 101 longitudinal and 90 transverse bladder images, the variability (SD) in distance measurement error was estimated for the bladder diameters. Using this SD, the variability in volume measurement error in the selected bladder image was also calculated.

Results

The urine production rate for fetuses of 20, 25, 30, 35 and 40 weeks is 4.2, 12.1, 22.7, 36.1 and 52.2 mL/h, respectively. The SD for volume measurement error when selecting bladder images with a volume of 5, 10, 20, 30 and 40 mL is 17.3%, 13.6%, 11.8%, 11.2% and 10.9% of the actual volume, respectively. The corresponding SD when measuring the volume of selected bladder images accounted for 3.7–2.0%.

Conclusions

The urine production rate presented here is in parity with recent previous reports. We distinguish between different kinds of measurement error. The variability was mostly related to the selection of appropriate bladder image, whereas measurement of the selected bladder image accounted for only a minor part of the resulting variability. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Congenital absence of portal vein in the fetus: a case report
Authors: Venkat‐Raman N. , Murphy K. W. , Ghaus K. , Teoh T.‐G. , Higham J. M. , Carvalho J. S.
Published: March 2003

Congenital absence of portal vein (CAPV) is a rare abnormality, which may be associated with other abnormalities. We report a case of prenatal diagnosis of absent portal vein confirmed on postnatal ultrasonography and computed tomography scan. The ultrasound features of CAPV include dilated intra‐abdominal segment of umbilical vein, dilated inferior vena cava and the presence of hyperechogenic areas in the liver. Blood coming from the umbilical vein directly drains into the inferior vena cava. The dilated intra‐abdominal segment of the umbilical vein shows high velocity pulsatile flow, resembling that of ductus venosus. These findings should prompt a careful search for the portal vein and any associated anomalies. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Ultrasound asessment of the fetal foramen ovale
Authors: Kiserud T. , Rasmussen S.
Published: March 2003

Objectives

Based on the assumption that the horizontal area between the fetal foramen ovale valve and the atrial septum (the outlet) represents the limiting structure for the foramen ovale flow, our objective was to determine the normal size of this section during the second half of pregnancy.

Methods

One hundred and thirty‐eight women with low‐risk singleton pregnancies were examined in a cross‐sectional study between 18 and 42 weeks of gestation. Using ultrasound imaging and M‐mode, the area and diameter between the foramen ovale valve and the atrial septum were determined in a four‐chamber view of the fetal heart above the foramen ovale limbus. The inferior vena cava cross section and right atrial width were also determined.

Results

The mean foramen ovale width increased from 3 mm at 18 weeks to 6 mm at term. Correspondingly, the horizontal area grew from 15 to 50 mm2. The mean ratio between this area and the area of the inferior vena cava fell from 1 at 18 weeks to 0.5 at term. The ratio between the transverse width of the foramen ovale and the right atrium remained at average 0.45–0.50 until 32 weeks, when a slight reduction was observed towards term.

Conclusions

Normal values for the horizontal cross section and transverse diameter of the foramen ovale outlet were established for the second half of pregnancy. In particular, the horizontal transverse diameter and its ratio to the right atrial width are easy to determine, and use of these measurements is thus suggested for the assessment of the fetal foramen ovale. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Cervical length at 22–24 weeks of gestation: comparison of transvaginal and transperineal‐translabial ultrasonography
Authors: Cicero S. , Skentou C. , Souka A. , To M. S. , Nicolaides K. H.
Published: March 2003

Objectives

To investigate the feasibility of measuring cervical length by transperineal or translabial sonography and compare the measurements obtained by this approach with those obtained transvaginally.

Methods

In 500 women measurement of cervical length by translabial‐transperineal sonography was attempted immediately before transvaginal scanning at 22–24 (median 23) weeks of gestation. In the first phase of the study, considered to be the learning period, 200 patients were examined and their results reviewed, before carrying out the second phase in which 300 patients were examined. A comparison was made of the patient acceptability of both techniques.

Results

Cervical length was successfully measured transvaginally in all cases. In the first phase of the study cervical length was measured by translabial‐transperineal sonography in 84% of the 200 patients but there was poor agreement with measurements obtained transvaginally and the 95% tolerance interval for paired observations was −11.0 mm to 16.1 mm. After audit of results it became apparent that the translabially‐transperineally derived images were inadequate in more than half of the cases but in those with adequate paired measurements there was a very good agreement between the two and the 95% tolerance interval for paired observations was −5.8 mm to 5.2 mm. In the second phase of the study special attention was paid towards recording measurements of cervical length only in cases where both the internal and external os were adequately visualized. Successful measurements by translabial‐transperineal sonography were obtained in 78% of cases and the 95% tolerance interval for paired observations was −5.8 mm to 6.1 mm. The degree of patient acceptability of the two methods was similar.

Conclusions

The findings of this study suggest that at 22–24 weeks of gestation the cervix can be visualized adequately by translabial‐transperineal sonography in about 80% of patients and the measurements of cervical length obtained by this approach are very similar to those obtained by transvaginal sonography. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Prediction of preterm delivery in twins by cervical assessment at 23 weeks
Authors: Skentou C. , Souka A. P. , To M. S. , Liao A. W. , Nicolaides K. H.
Published: March 2003

Objective

To establish the relation between cervical length at 23 weeks of gestation in twin pregnancies and risk of spontaneous delivery before 33 weeks.

Methods

Cervical length was measured by transvaginal sonography at 23 (range 22–24) weeks of gestation in 464 twin pregnancies attending for routine antenatal care. In the patients who were managed expectantly the relation between cervical length and the rate of spontaneous delivery before 33 weeks was determined.

Results

The cervical length distribution was skewed to the left and the median value was 36 mm. The rate of spontaneous delivery before 33 weeks was inversely related to cervical length at 23 weeks. It increased gradually from about 2.5% at 60 mm, to 5% at 40 mm and 12% at 25 mm, and exponentially below this length to 17% at 20 mm and 80% at 8 mm. Cervical length of 20 mm or less is found in about 8% of the population and this group contained about 40% of women delivering spontaneously before 33 weeks.

Conclusions

In twin pregnancies measurement of cervical length provides useful prediction of risk for spontaneous early preterm delivery. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Assessment of endothelial function in normal twin pregnancy
Authors: Savvidou M. D. , Donald A. E. , Nicolaides K. H.
Published: March 2003

Objective

To assess the maternal endothelial function in normal twin pregnancy.

Design

Cross‐sectional study.

Subjects

Endothelial function was investigated in 74 women with normal twin pregnancy at 11–30 weeks of gestation and the results were compared to previous reported findings in 98 women with normal singleton pregnancy and 19 non‐pregnant controls.

Methods

Endothelial function was assessed by measuring the changes of the brachial artery diameter in response to reactive hyperemia (flow‐mediated dilatation) using external high resolution ultrasound.

Results

Flow‐mediated dilatation of the brachial artery in both twin and singleton pregnancies was significantly higher than in non‐pregnant women (P = 0.002 and P = 0.02, respectively). However, there was no significant difference in flow‐mediated dilatation between women with twin and singleton pregnancy (9.61 ± 4.36 vs. 8.84 ± 3.18, P = 0.38). Resting vessel size, baseline flow and reactive hyperemia did not change significantly with gestation in twin pregnancy and were similar to values in singleton pregnancies and controls.

Conclusion

Our findings indicate that although in pregnancy endothelial function is enhanced, this change may not be affected by the number of fetoplacental units present. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
First‐trimester prenatal diagnosis of a familial subtelomeric translocation
Authors: Kilby M. D. , Brackley K. J. , Walters J. J. , Morton J. , Roberts E. , Davison E. V.
Published: March 2003

A new fluorescent in situ hybridization (FISH) technique utilizes a complete set of telomeric probes to screen for deletions or rearrangements within the subtelomeric regions of all chromosomes on a single slide. Such cryptic chromosome rearrangements would otherwise remain undetected by standard cytogenetic analysis.

In this case report, we describe the first‐trimester prenatal diagnosis of an unbalanced rearrangement in a family where such a cryptic subtelomeric rearrangement is segregating. Interestingly the fetus was also noted to have an increased nuchal translucency at the time first‐trimester chorionic villus sampling was performed and a FISH diagnosis made. The result was subsequently confirmed on fetal material obtained after elective termination of the pregnancy.

We believe this to be the first report in the literature (as by Medline, December 1999) of a first‐trimester prenatal diagnosis using such subtelomeric probes where confirmation by conventional cytogenetic analysis was not possible. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Improved early prediction of pre‐eclampsia by combining second‐trimester maternal serum inhibin‐A and uterine artery Doppler
Authors: Aquilina J. , Thompson O. , Thilaganathan B. , Harrington K.
Published: March 2003

Objective

To evaluate the screening efficacy of second‐trimester maternal serum inhibin‐A combined with uterine artery Doppler studies performed at 20 weeks' gestation for the prediction of pre‐eclampsia.

Methods

Six hundred and eighty‐nine consecutive unselected women who had inhibin‐A levels measured between 15 and 19 weeks' gestation subsequently had color flow pulsed Doppler of both uterine arteries at the time of the anomaly scan (mean 20.5, range 18–22 weeks' gestation). The main outcome measures were pre‐eclampsia and pre‐eclampsia requiring delivery before 37 weeks' gestation. The presence or absence of notches in the flow velocity waveform was noted, and the resistance index measured. Receiver operator curves were created for inhibin‐A and uterine artery Dopplers alone and in combination. Sensitivities for each method were compared at false‐positive rates of 3% and 7%.

Results

Thirty‐five women developed pre‐eclampsia, of whom 15 required delivery before 37 weeks' gestation. For a false‐positive rate of 7%, the sensitivity using bilateral notches/mean resistance index ≥ 0.65 was 60% with a positive likelihood ratio of 8.6 (confidence interval 5.7–12.6). For the same false‐positive rate, when bilateral notches/mean resistance index ≥ 0.55 and unilateral notches/mean resistance index ≥ 0.65 were combined with inhibin‐A ≥ 1.0 multiples of the median, the sensitivity improved to 71% and the positive likelihood ratio to 10.8 (confidence interval 7.4–15.4). For pre‐eclampsia requiring delivery before 37 weeks for a false‐positive rate of 3%, the sensitivity for bilateral notches improved from 27% to 60% and the positive likelihood ratio improved from 9.2 to 20.8 when uterine artery notch data was combined with inhibin‐A. The improvement in sensitivity for the combined method, compared to either inhibin‐A or uterine artery Dopplers alone, was statistically significant for both pre‐eclampsia (P < 0.05) and preterm pre‐eclampsia (P < 0.02).

Conclusion

Combination of second‐trimester serum inhibin‐A and uterine artery Doppler at 20 weeks improves the screening efficacy for the prediction of pre‐eclampsia especially when this necessitates early delivery. This combination might form the basis of an effective and practical early screening test for the condition. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Hemorrhage in rat fetuses from exposure to pulsed ultrasound
Authors: Dulovic Stanica , Davies A. S. , Birtles M. J. , Hessel G. R. , Ward R. N. , Mellor D. J.
Published: March 2003

Morphological effects of diagnostic pulsed Doppler ultrasound on fetal tissues, particularly lung, in rat fetuses from 16 to 22 days gestation were investigated in this study. A clinical ultrasound machine with two types of focused transducers (3.5, 5 MHz) was used with an adjustment for a small experimental animal. Three levels of exposures were represented by a mechanical index (MI) of 0.5, 0.6 and 1.0. Subpleural uni‐ or multifocal hemorrhage was found in exposed fetal lung. Fetal lungs were microscopically investigated by sectioning through the whole fetal body, which facilitated the discovery of hemorrhage at other sites. The percentage of exposed fetuses with hemorrhage is significant. A threshold for fetal hemorrhage could not be determined, because a significant variation due to age within each exposure group affected the results. Fetuses with lung in the canalicular stage of development (18–19 days) showed the greatest degree of lung hemorrhage. Following laparotomy of the dam to achieve a precise and uniform exposure, a small number of fetuses within each exposure group were exposed directly. There was no higher degree of hemorrhage in these fetuses, than in others indirectly exposed through the dam's abdominal wall.
Selective photocoagulation of communicating vessels in monochorionic twins with selective growth retardation
Authors: Quintero R. A. , Bornick P. W. , Allen M. , Morales W. J.
Published: March 2003

Objective:  The purpose of this study was to assess the outcome of monochorionic (MC) twins with selective intrauterine growth retardation (SIUGR) treated with selective laser photocoagulation of the communicating vessels (SLPCV).

Study design:  Patients at less than 26 weeks with MC SIUGR pregnancies were eligible for the study. SIUGR was defined as <10th percentile for gestational age. Absent or reverse end‐diastolic velocity in the umbilical artery of the SIUGR twin was required for eligibility after January 2000.

Results:  Thirty patients met criteria for the study: 17 were managed expectantly (group I), two underwent umbilical‐cord ligation of the SIUGR twin, and 11 underwent SLPCV (group II). Survival rates for at least one fetus were no different between groups I and II (14/17 or 82.3% vs. 8/11 or 72.3%, P = 0.4). However, concomitant demise of the co‐twin occurred in 4/7 patients and iatrogenic premature delivery for deterioration of the SIUGR twin was necessary in two patients in group, resulting in significant neonatal morbidity. Of the live‐born babies, neurological handicap was present in 3/22 (13.6%) vs. 0/12 in groups I and II, respectively (P < 0.0001).

Conclusions:  SIUGR in MC twins can be effectively treated with SLPCV. By unlinking the circulations between the fetuses, the pregnancy is rendered ‘functionally’ dichorionic, improving pregnancy management and resulting in decreased neonatal morbidity. This approach constitutes a new valuable alternative in the management of MC twin pregnancies with SIUGR and an extension of the use of SLPCV from TTTS to MC SIUGR. A randomized clinical trial of expectant management vs. SLPCV for MC SIUGR can be considered.