A randomized double-blinded controlled trial of hCG as luteal phase support in natural cycle frozen embryo transfer.
Does the use of hCG as luteal phase support in natural cycle frozen embryo transfer (FET) increase the ongoing pregnancy rate?



The use of hCG in natural cycle FET did not improve the ongoing pregnancy rate.



The use of luteal phase support in stimulated cycles has been associated with higher live-birth rates and the results are similar when using hCG or progesterone.



This is a randomized double-blinded controlled trial of 450 women recruited between August 2013 and October 2015.



Women with regular cycles undergoing natural cycle FET were recruited. Serial serum hormonal concentrations were used to time natural ovulation and at least Day 2 cleavage embryos were replaced. Patients were randomized into either: (i) the treatment group, receiving 1500 IU hCG on the day of FET and 6 days after FET, or (ii) the control group, receiving normal saline on these 2 days.



The ongoing pregnancy rate [60/225 (26.7%) in the treatment group vs 70/225 (31.3%) in the control group, odds ratio 1.242 (95% CI 0.825-1.869)], implantation rate and miscarriage rate were comparable between the two groups. In the treatment group, there were significantly more cycles with top quality embryos transferred and a significantly higher serum oestradiol level, but a comparable serum progesterone level, 6 days after FET. However, no significant differences were observed in serum oestradiol and progesterone levels 6 days after FET between the pregnant and non-pregnant women. In the multivariate logistic regression, the number of embryos transferred was the only significant factor predictive of the ongoing pregnancy rate after natural cycle FET.



This study only included FET with cleavage stage embryos and only hCG, not vaginal progesterone, was used as luteal phase support.



The findings in this study do not support the use of hCG for luteal phase support in natural cycle FET.



No external funding was used and there were no competing interests.



clinicaltrial.gov identifier: NCT01931384.



23/8/2013.



30/8/2013.
Department of Obstetrics and Gynecology, Queen Mary Hospital, 102 Pok Fu Lam Road, Hong KongSAR.
Vivian Chi Yan
VCY
Lee
Department of Obstetrics and Gynecology, The University of Hong Kong, 102 Pok Fu Lam Road, Hong KongSAR.
Raymond Hang Wun
RHW
Li
Department of Obstetrics and Gynecology, The University of Hong Kong, 102 Pok Fu Lam Road, Hong KongSAR.
William Shu Biu
WSB
Yeung
Department of Obstetrics and Gynecology, The University of Hong Kong, 102 Pok Fu Lam Road, Hong KongSAR.
H O
HO
Pak Chung
Department of Obstetrics and Gynecology, The University of Hong Kong, 102 Pok Fu Lam Road, Hong KongSAR.
Ernest Hung Yu
EHY
Ng
D000328:Adult; D006063:Chorionic Gonadotropin / Q000627:therapeutic use*; D004311:Double-Blind Method; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D006801:Humans; D050498:Live Birth; D008183:Luteal Phase; D011247:Pregnancy; D018873:Pregnancy Rate; D016896:Treatment Outcome
D006063:Chorionic Gonadotropin
frozen embryo transfer; hCG; luteal phase support; natural cycle; randomized controlled trial