Effect Of Different Endometrial Preparation Regimens On Pregnancy And Neonatal Outcomes After Frozen-thawed Blastocyst Transfer In Women With Polycystic Ovary Syndrome

BackgroundPolycystic ovary syndrome(PCOS)is the most common endocrine disorder in reproductive age women,and is a major cause of anovulatory infertility.There is a combination of signs and symptoms of hyperandrogenism and ovarian dysfunction in patients diagnosed with PCOS.Ovarian dysfunction in women with PCOS is characterized by follicle maturation arrest and disturbed dominant follicle selection.PCOS appeared to be the major predisposing factor for OHSS,which may potentially lead to fatal outcomes.Our multicenter randomized trial had demonstrated that among infertile women with PCOS,freeze-only strategy with delayed frozen embryo transfer increased the rate of live birth and decreased the risk of OHSS compared with fresh embryo transfer.With the development of techniques for embryo cryopreservation,the use of freeze-only strategy has been increasing for patients diagnosed with PCOS.Embryo-endometrial synchrony is critical for successful implantation,thus endometrial preparation is of vital importance for frozen-thawed embryo transfer.Despite the growing importance of frozen-thawed embryo transfer in the treatment of subfertility,the best solution for endometrial preparation in frozen-thawed embryo transfer cycles is still a matter of debate.Few studies have been done to the regimen for women with PCOS.Due to the feature of oligoovulation,women with PCOS need hormone replacement therapy(HRT)regimen or ovulation induction regimen for endometrial preparation before frozen-thawed embryo transfer.When it comes to live birth rates and pregnancy complications,there was rare evidence regarding the pros and cons of different endometrial preparation regimens for patients with PCOS.ObjectiveTo explore the optimal endometrial preparation regimen for frozen blastocyst transfer in women with PCOS.MethodsIn this study,we retrospectively analyzed the data of a total of 3997 first frozen-thawed blastocyst transfer cycles in patients with PCOS and compared the pregnancy and neonatal outcomes among different endometrial preparation methods of HRT regimen(n=3612),ovulation induction by human menopausal gonadotropin(hMG)regimen(n=228),and ovulation induction by letrozole regimen(n=157).ResultsAfter adjustment for confounders with multivariable logistic regression,the letrozole regimen group[62.4%vs.50.1%;adjusted odds ratio(aOR):1.48;95%confidence interval(CI):1.06-2.07]and the hMG regimen group(57.9%vs.50.1%;aOR:1.49;95%CI:1.12-1.96)were associated with a higher rate of live birth,compared with the group with HRT regimen.Similarly,the letrozole regimen group(63.1%vs.51.2%;aOR:1.67;95%CI:1.19-2.35)and the hMG regimen group(58.8%vs.51.2%;aOR:1.38;95%CI:1.05-1.83)had a higher ongoing pregnancy rate.The rate of pregnancy loss in the letrozole regimen group was lower than that in the HRT regimen group(18.3%vs.31.3%;aOR:0.48;95%CI:0.29-0.78).The risk of gestational diabetes mellitus(GDM)was higher in the hMG regimen group compared with HRT regimen group(11.5%vs.5.3%;aOR 2.44;95%CI:1.42-4.21).There was no difference in the incidences of preterm delivery,hypertension disorders of pregnancy,and preterm premature rupture of membranes among these three groups.And the incidences of neonatal complications including congenital anomalies and neonatal death were similar among these three groups.ConclusionIn patients with PCOS who underwent frozen-thawed blastocyst transfer,ovulation induction regimen with letrozeole or hMG for endometrial preparation was associated with a higher rate of live birth compared with HRT regimen.However,ovulation induction by hMG regimen may increase the risk of GDM.Future prospective randomized studies are needed to confirm our findings.