Gestational carrier pregnancy outcomes from frozen embryo transfer depending on the number of embryos transferred and preimplantation genetic testing: a retrospective analysis


      To compare gestational age, birth weight (BW), and live birth rates in gestational carriers (GC) after the transfer of 1 or 2 frozen embryo(s) with or without preimplantation genetic testing for aneuploidy (PGT-A), with the understanding that several social and economic factors may motivate intended parents to request the transfer of 2 embryos and/or PGT-A when using a GC.


      Retrospective cohort study


      An assisted reproductive technology practice.


      All frozen blastocyst transfers with GCs from 2009–2018.


      One or 2 embryo frozen embryo transfers with and without PGT-A.

      Main Outcome Measure(s)

      Live birth, preterm birth, and low BW.


      A total of 583 frozen embryo transfer cycles with vitrified high-grade blastocysts (grade BB or higher) to GCs were analyzed. Although the live birth rate was significantly greater in frozen embryo transfers with 2 embryos, after single embryo transfer (SET), the mean gestational age and BW of live births were statistically significantly greater than those of double embryo transfer (DET). The rate of multiple births was 1.9% for SET compared to 20.0% for DET per transfer. Only 3.8% of live births from SET experienced low BW and 0.6% had very low or extremely low BW. By comparison, 12.5% of DET live births were low BW and 5% were very low BW. After SET, 13.4% of live births were preterm, compared with 40% in DET. The analysis also included a total of 194 transfers with PGT-A compared to 389 cycles without. Overall, live births per transfer were not significantly different between these latter 2 subgroups.


      Frozen embryo transfer cycles in GCs with DET were associated with more preterm births and lower birth weights compared with those of SET. Intended parents and GCs should be counseled that DET is associated with greater risks of adverse pregnancy and perinatal outcomes, which mitigates higher live birth rates. The use of PGT-A did not appear to improve the live birth rate.
      Resultados en gestación subrrogada con transferencias de embriones congelados, dependiendo del número de embriones transferidos y del estudio genético preimplantacional: un estudio retrospectivo.


      Comparar la edad gestacional, el peso al nacimiento (BW) y las tasas de nacido vivo en gestación subrogada (GC) tras la transferencia de uno o dos embriones congelados con o sin estudio genético preimplantacional para aneuploidías (PGT-A), sabiendo que varios factores sociales y económicos pueden motivar a los padres pretendientes a solicitar la transferencia de dos embriones y/o a realizar PGT-A para una GC.


      Estudio de cohorte retrospectiva.


      Un centro médico de técnicas de reproducción asistida.


      Todas las transferencias de blastocistos congelados con y sin PGT-A, en gestación subrogada.


      Transferencia de uno o de dos embriones congelados con y sin PGT-A.

      Medida(s) principal(es) de resultado

      Nacimiento vivo, nacimiento pretérmino y bajo BW.


      Se analizaron un total de 583 ciclos de transferencia de embriones congelados con blastocitos vitrificados de alto grado (BB o mayor) en GCs. Aunque la tasa de nacimiento vivo fue significativamente mayor en las transferencias de dos embriones congelados, tras la transferencia de un único embrión (SET) la edad gestacional media y el BW de los nacidos vivos fueron estadísiticamente significativamente mayores que aquellas en las transferencias de dos embriones (DET). La tasa de nacimientos múltiples fue de 1.9% en SET, comparada con el 20.0% en DET, por transferencia. Sólo el 3.8% de los nacimientos vivos en SET sufrieron bajo BW y el 0.6% tuvieron muy bajo o extremadamente bajo BW. Comparativamente, el 12.5% de los nacimientos vivos en DET fueron bajo BW y el 5% fueron muy bajo BW. Tras el SET, el 13.4% de los nacimientos vivos fue pretérmino, comparado con el 40% en DET. El análisis también incluyó a un total de 194 transferencias con PGT-A comparadas con 389 ciclos sin él. En general, los nacimientos vivos por transferencia no fueron significativamente diferentes entre estos dos últimos subgrupos.


      Los ciclos de transferencia de embriones congelados en GCs con DET se asociaron con más nacimientos pretérminos y con pesos menores al nacer, comparados con aquellos con SET. Se debe asesorar a los padres pretendientes y a las GCs que el DET se asocia con mayores riesgos de resultados gestacionales y perinatales adversos, lo que impide mayores tasas de nacimiento vivo. El uso de PGT-A no pareció mejorar la tasa de nacido vivo.

      Key Words

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        • Perkins K.M.
        • Boulet S.L.
        • Jamieson D.J.
        • Kissin D.M.
        National Assisted Reproductive Technology Surveillance System (NASS) Group. Trends and outcomes of gestational surrogacy in the United States.
        Fertil Steril. 2016; 106: 435-442.e2
        • Jadva V.
        • Imrie S.
        • Golombok S.
        Surrogate mothers 10 years on: a longitudinal study of psychological well-being and relationships with the parents and child.
        Hum Reprod. 2015; 30: 373-379
        • Dar S.
        • Lazer T.
        • Swanson S.
        • Silverman J.
        • Wasser C.
        • Moskovtsev S.I.
        • et al.
        Assisted reproduction involving gestational surrogacy: an analysis of the medical, psychosocial and legal issues: experience from a large surrogacy program.
        Hum Reprod. 2015; 30: 345-352
        • Woo I.
        • Hindoyan R.
        • Landay M.
        • Ho J.
        • Ingles S.A.
        • McGinnis L.K.
        • et al.
        Perinatal outcomes after natural conception versus in vitro fertilization (IVF) in gestational surrogates: a model to evaluate IVF treatment versus maternal effects.
        Fertil Steril. 2017; 108: 993-998
        • Brinsden P.R.
        Gestational surrogacy.
        Hum Reprod Update. 2003; 9: 483-491
        • Pavlovic Z.
        • Hammer K.C.
        • Raff M.
        • Patel P.
        • Kunze K.N.
        • Kaplan B.
        • et al.
        Comparison of perinatal outcomes between spontaneous vs. commissioned cycles in gestational carriers for single and same-sex male intended parents.
        J Assist Reprod Genet. 2020; 37: 953-962
        • Peters H.E.
        • Schats R.
        • Verhoeven M.O.
        • Mijatovic V.
        • de Groot C.J.M.
        • Sandberg J.L.
        • et al.
        Gestational surrogacy: results of 10 years of experience in the Netherlands.
        Reprod Biomed Online. 2018; 37: 725-731
        • Devine K.
        • Connell M.T.
        • Richter K.S.
        • Ramirez C.I.
        • Levens E.D.
        • DeCherney A.H.
        • et al.
        Single vitrified blastocyst transfer maximizes liveborn children per embryo while minimizing preterm birth.
        Fertil Steril. 2015; 103: 1454-1460.e1
        • Segal T.R.
        • Kim K.
        • Mumford S.L.
        • Goldfarb J.M.
        • Weinerman R.S.
        How much does the uterus matter? Perinatal outcomes are improved when donor oocyte embryos are transferred to gestational carriers compared to intended parent recipients.
        Fertil Steril. 2018; 110: 888-895
        • Coates A.
        • Bankowski B.J.
        • Kung A.
        • Griffin D.K.
        • Munne S.
        Differences in pregnancy outcomes in donor egg frozen embryo transfer (FET) cycles following preimplantation genetic screening (PGS): a single center retrospective study.
        J Assist Reprod Genet. 2017; 34: 71-78
        • Wang A.Y.
        • Dill S.K.
        • Bowman M.
        • Sullivan E.A.
        Gestational surrogacy in Australia 2004-2011: treatment, pregnancy and birth outcomes.
        Aust NZ J Obstet Gynaecol. 2016; 56: 255-259
        • De Sutter P.
        • Delbaere I.
        • Gerris J.
        • Verstraelen H.
        • Goetgeluk S.
        • Van der Elst J.
        • et al.
        Birthweight of singletons after assisted reproduction is higher after single- than after double-embryo transfer.
        Hum Reprod. 2006; 21: 2633-2637
        • Stillman R.J.
        • Richter K.S.
        • Jones H.W.
        Refuting a misguided campaign against the goal of single-embryo transfer and singleton birth in assisted reproduction.
        Hum Reprod. 2013; 28: 2599-2607
        • Richter K.S.
        • Ginsburg D.K.
        • Shipley S.K.
        • Lim J.
        • Tucker M.J.
        • Graham J.R.
        • et al.
        Factors associated with birth outcomes from cryopreserved blastocysts: experience from 4,597 autologous transfers of 7,597 cryopreserved blastocysts.
        Fertil Steril. 2016; 106: 354-362.e2
        • Gardner D.K.
        • Schoolcraft W.B.
        Culture and transfer of human blastocysts.
        Curr Opin Obstet Gynecol. 1999; 11: 307-311
        • Devine K.
        • Richter K.S.
        • Widra E.A.
        • McKeeby J.L.
        Vitrified blastocyst transfer cycles with the use of only vaginal progesterone replacement with Endometrin have inferior ongoing pregnancy rates: results from the planned interim analysis of a three-arm randomized controlled noninferiority trial.
        Fertil Steril. 2018; 109: 266-275
        • Blencowe H.
        • Cousens S.
        • Oestergaard M.Z.
        • Chou D.
        • Moller A.B.
        • Narwal R.
        • et al.
        National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: a systematic analysis and implications.
        Lancet. 2012; 379: 2162-2172
        • Schieve L.A.
        • Meikle S.F.
        • Ferre C.
        • Peterson H.B.
        • Jeng G.
        • Wilcox L.S.
        Low and very low birth weight in infants conceived with use of assisted reproductive technology.
        N Engl J Med. 2002; 346: 731-737
        • Hamilton B.E.
        • Martin J.A.
        • Ventura S.J.
        Births: preliminary data for 2012.
        Natl Vital Stat Rep. 2013; 62: 1-20
        • De Neubourg D.
        • Gerris J.
        • Mangelschots K.
        • Van Royen E.
        • Vercruyssen M.
        • Steylemans A.
        • et al.
        The obstetrical and neonatal outcome of babies born after single-embryo transfer in IVF/ICSI compares favourably to spontaneously conceived babies.
        Hum Reprod. 2006; 21: 1041-1046
        • Gibbons W.E.
        • Cedars M.
        • Ness R.B.
        • Society for Assisted Reproductive Technologies Writing Group
        Toward understanding obstetrical outcome in advanced assisted reproduction: varying sperm, oocyte, and uterine source and diagnosis.
        Fertil Steril. 2011; 95: 1645-1649.e1
        • White P.M.
        “One for Sorrow, Two for Joy?”: American embryo transfer guideline recommendations, practices, and outcomes for gestational surrogate patients.
        J Assist Reprod Genet. 2017; 34: 431-443
        • Center for Disease Control and Prevention, American Society for Reproductive Medicine, Society for Assisted Reproductive Technology.
        2017 Assisted Reproductive Technology Success Rates: National Summary and Fertility Clinic Reports.
        U.S. Dept. of Health and Human Services, Washington, D.C.2017
        • Farquhar C.
        Avoiding multiple pregnancies in assisted reproductive technologies: transferring one embryo at a time should be the norm.
        Fertil Steril. 2020; 114: 671-672
        • Russell R.B.
        • Green N.S.
        • Steiner C.A.
        • Meikle S.
        • Howse J.L.
        • Poschman K.
        • et al.
        Cost of hospitalization for preterm and low birth weight infants in the United States.
        Pediatrics. 2007; 120: e1-e9
        • Makhijani R.B.
        • Coulter M.
        • Thorne J.
        • Bartels C.
        • Nulsen J.
        • Engmann L.
        • et al.
        Impact of preimplantation genetic testing for aneuploidy (PGT-A) on gestational carrier (GC) cycles in the United States.
        Fertil Steril. 2019; 112: e227
        • Tilstra A.M.
        • Masters R.K.
        Worth the Weight? Recent trends in obstetric practices, gestational age, and birth weight in the United States.
        Demography. 2020; 57: 99-121