PGT for Aneuploidy Does Not Enhance Live Birth in Young Patients (≤35 Years): a Randomized Controlled Trial of Single Blastocyst Frozen Embryo Transfers (ClinicalTrials.Gov ID: NCT03095053)
Phase: NA
Conditions: Pregnancy
Sponsor: Antalya IVF

Document date updated before downloading to ClinicalTrials.gov: 5 March 2018 
 
Final title: PGT for aneuploidy does not enhance live birth in young patients (≤ 35 years): a 
randomized controlled trial of single blastocyst frozen embryo transfers (ClinicalTrials.gov 
ID: NCT03095053) 
Short title: PGT-A versus morphological score blastocyst selection 
Authors: 1Kemal Ozgur MD, 1Murat Berkkanoglu MD, 1Hasan Bulut MD, 2Gonul Didem Akay 
Yoruk MD PhD, 2Nevrah Nal Candurmaz, MSc PhD, 1Kevin Coetzee PhD. 
1Antalya IVF, Antalya, 07080, Turkey. 
2BiyoGenom, Genetic Diagnostic Center, Antalya, 07040, Turkey 
 
Registered Title: Conventional blastocyst morphology versus comprehensive chromosome 
screening selection: a randomized control superiority trial 
Short title: CCS versus blastocyst morphology selection 
Secondary identifiers: Optimizing implantation in FET 
Sponsor: Antalya IVF 
Principal Investigator: Kevin Coetzee 
Official Title: Scientific Advisor 
Affiliation: Antalya IVF 
Collaborators: Kemal Ozgur, Hasan Bulut, Murat Berkkanoglu  
 
Human Subjects Review: Board Status: Approved 
Board Name: Akdeniz University Medical Faculty Clinical Research Ethics Committee 
Board Affiliation: Turkish Health Ministry Ethics Committee 
Phone: +90 (242) 249 6954 
Email: etik@akdeniz.edu.tr 
Address: Akdeniz Universitesi Rektorlugu, Etik Kurulu, PK: 10 Dumlupinar Bulvari, 
07058, Konyaalti, Antalya, Turkey 
 
Changes to original registration: 
Primary outcome measure: the primary outcome measure was changed from ongoing pregnancy 
(i.e., clinical pregnancy at >14 weeks of gestation) to the preferred outcome of live birth (LB, a 
delivery at >20 weeks, with a live infant). 
 

The AFC cut-off was changed to ≥5 (changed from ≥10) to be in line with the definition of 
decreased ovarian reserve and increase the eligible population. 
 
Trial registration: ClinicalTrials.gov ID: NCT03095053 
Protocol submission: 23 March 2017 
Protocol revised submission: 28 March 2017 
Randomized Controlled Trial registered and posted: 29 March 2017 
Data collection start: 21 February 2018  
Data collection was commenced at >20 weeks from the date of last patient randomized had 
undergone FET 
Data analysis start: 25 April 2018 
 
 

Description 
Brief description 
Introduction 
Embryo aneuploidy is likely the leading cause of implantation failure in IVF cycles. Since the 
inception of IVF, non-invasive morphology based scoring has been the most widely used embryo 
selection method, resulting in relatively low embryo implantation rates. Our understanding of the 
optimal conditions required for in vitro embryo culture in IVF has advanced significantly over the 
past two decades. The implementation of improved in vitro embryo culture technologies (i.e., 
culture media and incubators) has resulted in an increase in the number of good quality embryos 
and consequently in increased numbers of blastocysts. While blastocyst transfers have seemingly 
improved the reproductive outcomes of IVF, they still remain suboptimal. The main objective of 
this randomized controlled trial (RCT) will be to investigate whether preimplantation genetic testing 
(i.e., PGT with comprehensive chromosome screening (CCS)) for aneuploidy is a superior embryo 
selection method, with the live birth outcomes of euploid blastocyst frozen embryo transfers (FET) 
compared with the LB outcomes of unknown-ploidy blastocyst FET, with blastocysts selected on 
(standard) morphological score. 
Methods 
This RCT will be conducted at a single private IVF centre performing routine segmented-IVF, with 
intracytoplasmic sperm injection (ICSI), blastocyst freeze-all, and artificial frozen embryo transfer 
(art-FET). Normo-ovulatory infertile patients, with maternal age ≤35 years and at least two 
blastocysts with a morphology score of 2BB cryopreserved, will be randomized by computer-
generated randomized allocation to either the PGT or morphology arm of the trial. All transfers will 
be single embryo transfers (SET), with only the first FET cycles following freeze-all to be analyzed.  
Consent and Ethics 
Akdeniz University Medical Faculty Clinical Research Ethics Committee has approved the trial 
(reference number: 2015/399), with anonymized results to be released in ClinicalTrials.gov. All 
patients will provide informed consent, which included an agreement for the use of anonymised 
data for research and SET. 
 
 

Full description 
Introduction 
Embryo aneuploidy is likely the leading cause of implantation failure in IVF cycles. Since the 
inception of IVF, non-invasive morphology based scoring has been the most widely used embryo 
selection method, resulting in relatively low embryo implantation rates. Embryo morphology 
assessment methods have significant limitations (i.e., the assessments are subjective and the method 
uses fixed time-point assessments to define dynamic embryo development) and shortcomings (i.e., 
exposes embryos to sub-optimal conditions during assessment). Notwithstanding the limitations and 
shortcomings of this method its use worldwide has continued, because it is a relatively simple and 
non-invasive method and its scores have been shown to be (moderately) positively correlated to 
embryo euploidy, ongoing pregnancy, and live birth (Van Royen et al., 1999, Ahlstrom et al., 2011, 
Forman et al., 2013, Capalbo et al., 2014, Oron et al., 2014, Rhenman et al., 2015). 
 
However multiple gestations still represents one of the most significant complications in IVF, 
which are mainly the result of multiple-embryo embryo transfers, with multiple-embryo transfers 
used to overcome the relatively low embryo implantation rates in IVF. Our understanding of the 
optimal conditions required for in vitro embryo culture in IVF has advanced significantly in the past 
two decades. The implementation of improved in vitro embryo culture technologies (i.e., culture 
media and incubators) has resulted in an increase in the number of good quality embryos and 
consequently in the numbers of blastocysts. While blastocyst transfers have seemingly improved the 
reproductive outcomes in IVF, the use of SET and PGT technologies have revealed embryo 
implantation still to be sub-optimal (Schoolcraft et al., 2013). New CCS platforms are a major 
breakthrough in PGT, allowing 24-chromosome screening to be performed with high degree of 
accuracy from single cells (Harper and Harton, 2010). The evidence that morphology scores were 
only moderately associated with euploidy and that the transfer of PGT predicted euploid embryos 
resulted in higher implantation rates (Dahdouh et al., 2015), has seen the continued use of 
morphology based scoring methods increasingly being challenged. 
 
In addition to all the other advances in IVF, significant improvements have also been made in 
cryopreservation technologies. These improvements have resulted in significant improvements in 
frozen-thawed embryo survival (i.e. minimizing of risks), post-thaw developmental competence 
(Cobo et al., 2012; Balaban et al., 2008), and in the reproductive outcomes of FET (Evans et al., 
2014; Ozgur et al., 2015). The benefits of FET include; the transfer of embryos to a more 
physiologic endometrium (i.e., early luteal phase), the ability to time transfers more accurately, and 

the ability to use patient specific endometrial preparations (Casper and Yanushpolsky, 2016, 
Franasiak et al., 2016; Groenewoud et al., 2013, Yarali et al., 2016).  
 
Moreover, the hypotheses of PGT require to be confirmed in further robust RCT before its 
implementation in routine IVF. 
 
Objectives 
The primary objective of this RCT will be to investigate whether PGT for aneuploidy as a 
blastocyst selection method is superior to standard morphology scoring blastocyst selection, 
comparing the reproductive outcomes in FET cycles. The decision to transfer all blastocysts in FET 
will eliminate any potential impact of ovarian stimulation confounding on endometrial receptivity 
and to use freeze-all cycles will allow the use of the primary blastocysts of blastocyst cohorts. The 
primary outcome measure of this trial will be LB, with a LB defined as a pregnancy cycle 
delivering at >20 weeks of gestation. 
 
Secondary objectives 
The secondary objective of the RCT will be to investigate whether euploid blastocyst transfer 
results in reduced miscarriage, with a miscarriage defined as a clinical pregnancy lost at <20 weeks 
of gestation. 
 
Keywords: blastocyst; comprehensive chromosome screening; euploidy; frozen embryo transfer 
 
Funding: This RCT will not receive any specific grant from funding agencies in the public, 
commercial, or not-for-profit sectors, and therefore will be wholly funded by centre running the 
trial. 
 
Declaration of Interests: The authors declare no conflicts of interest. 
 
References 
Ahlstrom A, Westin C, Reismer E, Wikland M, Hardarson T. Trophectoderm morphology: an 
important parameter for predicting live birth after single blastocyst transfer. Hum Reprod 2011; 26: 
3289–3296. 
 
Balaban B, Urman B, Ata B, Isiklar A, Larman MG, Hamilton R, et al. A randomized controlled 
study of human day 3 embryo cryopreservation by slow freezing or vitrification: vitrification is 

associated with higher survival, metabolism and blastocyst formation. Hum Reprod 2008; 23: 
1976–1982. 
 
Capalbo A, Rienzi L, Cimadomo D, Maggiulli R, Elliott T, Wright G, Nagy ZP, Ubaldi FM. 
Correlation between standard blastocyst morphology, euploidy and implantation: an observational 
study in two centers involving 956 screened blastocysts. Hum Reprod. 2014; 29: 1173-1181. 
 
Casper RF, Yanushpolsky EH. Optimal endometrial preparation for frozen embryo transfer cycles: 
window of implantation and progesterone support. Fertil Steril 2016; 105: 867–872. 
 
Cobo A, de los Santos MJ, Castello D, Gamiz P, Campos P, Remohí J. Outcomes of vitrified early 
cleavage-stage and blastocyst-stage embryos in a cryopreservation program: evaluation of 3,150 
warming cycles Fertil Steril 2012; 98: 1138–1146. 
 
Dahdouh EM, Balayla J, Garcia-Velasco JA. Comprehensive chromosome screening improves 
embryo selection: a meta-analysis. Fertil Steril 2015; 104:1503–12. 
 
Evans J, Hannan NJ, Edgell TA, Vollenhoven BJ, Lutjen PJ, Osianlis T, Salamonsen LA, Rombauts 
LJF. Fresh versus frozen embryo transfer: backing clinical decFET isions with scientific and 
clinical evidence. Hum Reprod Update 2014; 20: 808–821. 
 
Forman EJ, Upham KM, Cheng M, Zhao T, Hong KH, Treff NR, Scott Jr. RT. Comprehensive 
chromosome screening alters traditional morphology-based embryo selection: a prospective study 
of 100 consecutive cycles of planned fresh euploid blastocyst transfer. Fertil Steril 2013; 100: 718-
724. 
 
Franasiak JM, Ruiz-Alonso M, Scott RT, Simon C. Both slowly developing embryos and a variable 
pace of luteal endometrial progression may conspire to prevent normal birth in spite of a capable 
embryo Fertil Steril 2016; 105: 861–866. 
 
Groenewoud ER, Cantineau AEP, Kollen BJ, Macklon NS, Cohlen BJ. What is the optimal means 
of preparing the endometrium in frozen–thawed embryo transfer cycles? A systematic review and 
meta-analysis. Hum Reprod Update 2013; 19: 458–470. 
 
Harper JC, Harton G. The use of arrays in PGD/PGS. Fertil Steril 2010; 94:1173–1177. 

 
Oron G, Son WY, Buckett W, Tulandi T, Holzer H. The association between embryo quality and 
perinatal outcome of singletons born after single embryo transfers: a pilot study. Hum Reprod 2014; 
29: 1444-1451. 
 
Ozgur K, Berkkanoglu M, Bulut H, Isikli A, Coetzee K. Higher clinical pregnancy rates from 
frozen-thawed blastocyst transfers compared to fresh blastocyst transfers: a retrospective matched-
cohort study. J Assist Reprod Genet 2015; 32:1 483-1490. 
 
Rhenman A, Berglund L, Brodin T, Olovsson M, Milton K, Hadziosmanovic N, Holte J. Which set 
of embryo variables is most predictive for live birth? A prospective study in 6252 single embryo 
transfers to construct an embryo score for the ranking and selection of embryos. Hum Reprod 2015; 
30: 28-36. 
 
Schoolcraft WB, Katz-Jaffe MG. Comprehensive chromosome screening of trophectoderm with 
vitrification facilitates elective single-embryo transfer for infertile women with advanced maternal 
age. Fertil Steril 2013;100: 615–9. 
 
Van Royen E, Mangelschots K, De Neubourg D, Valkenburg M, Van de Meerssche M, Ryckaert G, 
Eestermans W, Gerris J. Characterization of a top quality embryo, a step towards single-embryo 
transfer. Hum Reprod 1999; 14: 2345–2349. 
 
Yarali H, Polat M, Mumusoglu S, Yarali I, Bozdag G. Preparation of endometrium for frozen 
embryo replacement cycles: a systematic review and meta-analysis. J Assist Reprod Genet. 2016; in 
print. 
 
Materials and methods 
Study design 
The RCT will be performed as a single private IVF center trial. The patient population of the trial 
will include young patients undergoing autologous blastocyst freeze-all IVF cycles from March 
2017. In this trial, a patient will undergo a blastocyst-freeze-all cycle after ICSI and only the 
reproductive outcomes of the first FET following the freeze-all will be analyzed. Currently at the 
trial centre more than 95% of cycles are extended culture cycles and more than 80% of these cycles 
result in freeze-all cycles, with a live birth rate after the first FET of >45% per oocyte retrieval. 
 

Setting 
Antalya IVF is located in Antalya, Turkey.  
Antalya IVF, Halide Edip Cd. No. 7 Kanal Mh., Antalya, 07080, Turkey  
Telephone: +90 242 3454700 
Facsimile: +90 242 3454747 
www.antalyatupbebek.com.tr 
 
Study population/Participants and recruitment 
The trial participants will consist of infertile patient-couples attending Antalya IVF for autologous 
segmented-IVF treatment. Patients will be informed of the trial at their clinical consultation before 
commencing treatment, at which the trial procedures and the likely reproductive outcomes will be 
discussed. All patients who consent to participation and who satisfy the inclusion criteria will 
undergo the same standard IVF procedures; ovarian stimulation (OS), oocyte retrieval, ICSI, 
extended embryo culture, blastocyst vitrification, and artificial FET. 
 
Eligibility criteria 
Patient-couples eligible for inclusion in the trial must satisfy the following criteria; female age of 
≤35 years, female body mass index (BMI) of ≥18 or ≤35 kg/m2, antral follicle count (AFC) of ≥5 
(changed from ≥10), normo-ovulatory, intend to use autologous oocytes, and have ≥2 blastocysts 
with a morphological score of 2BB on day 5 of embryo development. 
 
Exclusion criteria 
Patient couples will be excluded from the trial for the following reasons, patients with drug 
contraindications, patients with pathophysiology unrelated to reproduction, patients with 
intrauterine pathophysiologies, patients with no blastocysts, patients with <2 blastocysts with a 
morphological score of 2BB.  
 
Randomisation 
Patient couples who satisfy the inclusion criteria and who completed an informed consent will 
randomized by computer generated number in a 1:1 ratio on day 5 of in vitro embryo culture to the 
two arms, with the FET drug prescription indicating allocation to the the PGT group, in which all 
blastocysts will be assessed according to standard morphological parameters, with the best scoring 
blastocyst to undergo biopsy and PGT for aneuploidy or the morphology group, in which all 
blastocysts will be assessed according to standard morphological parameters, with the best scoring 
blastocyst selected for transfer (figure 1). Patient couples in the PGT group will be subgrouped 

according to whether the blastocyst biopsied is predicted to be euploid (the euploid subgroup) or 
aneuploid (the aneuploid subgroup). In the aneuploid group the next best morphology scoring 
blastocyst will be transferred. 
 
Interventions 
Controlled ovarian stimulation, oocyte pickup, and embryo culture 
All patients will have an ultrasound examination on cycle day 2 or 3 to assess the state of the 
patients ovaries and uterus, and perform an antral follicle count (follicles >2≤10 mm), before 
commencing flexible start gonadotropin-releasing (GnRH) antagonist (0.25mg, Cetrotide, Merck 
Serono, Istanbul, Turkey) co-treatment OS protocols. Follicular development will be stimulated 
using a combination of rFSH (150-375 IU, Gonal-F, Merck Serono, Istanbul, Turkey) and hMG 
(75-150 IU, Menopur, Ferring Pharmaceuticals, Mumbai, India). The gonadotropin doses will be 
based on maternal age, BMI, AFC, and previous OS outcome. Final oocyte maturation will be 
triggered when three or more follicles reach ≥17 mm, with GnRHa (0.2 mg, Gonapeptyl®, Ferring 
Pharmaceuticals, India). 
 
Oocyte retrievals will be performed 36 hours after triggering using transvaginal ultrasound (TVS) 
guided follicle aspiration (follicular aspiration needle, 461230LF, Rheinbach, Germany) 
procedures. Oocyte collection and manipulation will be performed using Cook Medical media 
(Sydney IVF, Brisbane, Australia) and embryo culture will be performed using SAGE 1-Step™ 
medium (67010010A, SAGE, Origio, Malov, Denmark), with no change of media during culture. 
Incubation conditions were set at 6% CO2, 5% O2 and 37.0oC (G185 Long Term Flat Bed 
Incubators, K-Systems, Kivex Biotec ltd, Birkerod, Denmark). All oocyte inseminations will be 
performed using ICSI, with daily embryo development assessments, thereafter. 
 
Blastocyst assessment 
Blastocysts will be graded according to the 3-part grading system (Gardner et al., 2000), with a 
blastocyst grade including an assessment of blastocyst expansion (grade 1 to 6), inner cell mass 
morphology (ICM, A to C, according to the number and degree of compaction of the cells), and 
trophectoderm morphology (TE, A to C, according to the number, size and contiguous arrangement 
of the trophectoderm cells). Blastocysts with a grade of ≥2BB were regarded as usable. 
Gardner DK, Lane M, Stevens J, Schlenker T, Schoolcraft WB. Blastocyst score affects 
implantation and pregnancy outcome: towards a single blastocyst transfer. Fertil Steril 2000; 
73: 1155-1158. 
 

Biopsy 
Blastocysts with morphological grades of ≥2BB will be biopsied on day 5 of in vitro embryo 
culture. Biopsies will be performed using using a Hamilton Thorne Zilos laser (Hamilton Thorne, 
MA, USA), with 3-10 trophectoderm cells removed from the blastocysts.  
 
Comprehensive chromosome screening 
All trophectoderm biopsies will be processed for analysis by Next-Generation Sequencing (NGS, 
illumina, California, USA).  
 
Blastocyst cryopreservation 
Vitrification and warming of blastocysts will be performed using ultra-rapid technologies (Cryotop, Kitazato 
BioPharma Co. Ltd, Fuji-city, Japan), according to the manufacturer’s guidelines. Blastocysts were warmed 
and transferred on the same day; after warming the blastocysts were placed in incubation for approximately 2 
hours and then morphologically reassessed. 
 
Cycle programming and endometrial preparation 
All patients will undergo a standard endometrial preparation protocol, using GnRHa to programme 
the start of the endometrial preparation (Ozgur et al., 2016).  
Ozgur K, Berkkanoglu M, Bulut H, Humaidan P, Coetzee K. Agonist depot versus OCP 
programming of frozen embryo transfer: a retrospective analysis of freeze-all cycles. J Assist Reprod 
Genet 2016; 33: 207-214. 
 
Frozen embryo transfer art-FET  
All transfers will be SET and performed in art-FET. Embryo transfers will be performed with glass 
syringes (50µL, Hamilton, Giarmata, Romania) attached to embryo replacement catheters (Wallace, 
Smiths Medical, Kent, UK), with trans-abdominal ultrasound guidance. All blastocyst FET will be 
scheduled to be performed on the 6th day of progesterone administration (90 mg, twice-a-day, 
Crinone® 8%, Merck Serono, Turkey) to time the day of transfer, with progesterone administration 
commencing on day 15 of endometrial preparation. 
 
Outcome measures 
Patient variables recorded will be maternal age, infertility duration and etiology, BMI, AFC, and 
endometrial thickness. The treatment cycle variables recorded were oocyte number, mature oocyte 
number, blastocyst number (i.e., the number usable blastocysts, with grade ≥2BB), oocyte maturity, 
oocyte fertilization, blastocyst rate (i.e., the ratio of the number of blastocysts to the number of 2PN 
zygotes). The primary outcome measure recorded will be LB (changed from ongoing pregnancy), 

with clinical pregnancy and miscarriage as secondary outcomes. A LB cycle will be defined as a 
pregnancy cycle that delivered at >20 weeks of gestation, resulting in a live infant. A clinical 
pregnancy will be defined as a cycle with a fetal sac observed on ultrasound after 5 weeks of 
gestation. A biochemical pregnancy will be defined as a cycle with an arbitrary serum βhCG 
concentration of >29 IU/L. Pregnancy tests will be performed 9 days after the FET. 
 
Statistics 
Statistical Package for Social Science 11.5 (SPSS version 11.5) was used for the statistical analysis 
of characteristics and outcome measures (i.e., p values and Risk Ratios (RR)). Continuous data were 
analyzed either with the student’s t-test or Mann-Whitney-U test, depending on outcome of 
normality testing (Shapiro-Wilk). Categorical data were analyzed using either the chi-square test or 
Fisher’s Exact-test (i.e., for low sample numbers). A p < 0.05 indicated outcomes of significant 
difference. 
 
Sample size calculation 
At the trial centre the overall ongoing pregnancy rate was 66% for the transfer CCS euploid 
blastocysts, while the overall ongoing pregnancy rate was 52% for blastocysts selected for transfer 
by morphology only. The sample sizes required to have 80% chance of detecting a difference of 
20% at a significance level of 0.05 was calculated to be 74. 
 
Ethics 
Akdeniz University Medical Faculty Clinical Research Ethics Committee has approved the trial 
(reference number: 2015/399), with anonymized results to be released in ClinicalTrials.gov. All 
patient will be provided with trial information, with all patients wishing to participate in the trial 
providing informed consent, which included an agreement for the use of anonymised data for 
research, before commencing treatment.  
 
All treatment procedures and medical devices used in treatments have been approved by the Turkish 
Health Ministry and the management and quality control of the procedures performed accredited by 
TÜV Rheinland Cert GmbH (Assisted Reproductive Technologies; ISO 9001:2008; Cert No. 01 
100 062424). 
 
Data 
All data pertaining to the trial and required for anlysis will be collected by the principal investigator 
from the IVF database of Antalya IVF at >20 weeks after the last patient randomized had 

undergone FET. A LB cycle will defined as a pregnancy cycle delivered at >20 weeks of gestation. 
A clinical pregnancy will defined as a pregnancy cycle with a fetal sac observed on ultrasound at >5 
weeks of gestation. A miscarriage will be defined as a clinical pregnancy lost at <20 weeks of 
gestation. 
 

Figure 1: Study design 
 
 
  
Enrollment 
Inclusion criteria: 
Own oocytes; normo-ovulatory; ≤35 
years of age; ≤3 embryo transfers; ≥18-
≤35 kg/m2 BMI; ≥5 AFC. 
Informed consent 
 
  
 
 
 
 
  
Eligible patients 
 
 
 
  
 
 
 
 
 
 
OS, oocyte retrieval, ICSI, 
extended in vitro embryo 
culture 
Exclusion: 
No oocytes retrieved; <2 blastocysts with 
morphological grade of ≥2BB 
 
  
 
 
 
  
≥2 blastocysts with 
morphological grade of ≥2BB 
Assessment: 
All blastocysts assessed morphologically 
 
  
 
 
 
  
Randomization 
 
 
 
 PGT group  
1 blastocysts with 
morphological grade 
of ≥2BB biopsied 
and assessed by 
NGS 
 
Morphology 
group 
 
 
 
All blastocysts with 
morphological grade 
of ≥2BB 
cryopreserved 
 
All blastocysts with 
morphological grade 
of ≥2BB 
cryopreserved 
 
 
 
 
 
 
 
aneuploid blastocyst 
 
euploid blastocyst 
 
 
 
 
  
 
 
Aneuploid 
subgroup: transfer 
of morpholoically 
assessed blastocyst 
 Euploid 
subgroup: transfer 
of a euploid 
blastocyst 
 
Morphology 
group: transfer of a 
morpholoically 
assessed blastocyst 
 
 
 
 
Positive βhCG 9 
days of transfer 
 
Positive βhCG 9 
days of transfer 
 
Positive βhCG 9 
days of transfer 
 
 
 
 
 
 
 

Fetal sac on 
ultrasound >5 
weeks 
 Fetal sac on 
ultrasound >5 
weeks 
Secondary outcome 
measure 
Fetal sac on 
ultrasound >5 
weeks 
 
 
  
 
 
 
Live birth: 
Delivery at >20 
weeks 
 Live birth: 
Delivery at >20 
weeks 
Primary outcome 
measure 
Live birth: 
Delivery at >20 
weeks