Objective:To investigate the impact of different luteal phase support protocols on pregnancy outcomes in patients aged ≤35 years undergoing modified natural cycle frozen-thawed embryo transfer (mNC-FET).Methods:A retrospective cohort study was conducted to analyze 2 086 cycles of patients aged ≤35 years who received mNC-FET cycles in Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University from January 2018 to December 2020. The cycles were divided into three groups based on luteal phase support protocols used. The patients received a combination of progesterone soft capsule and dydrogesterone in the group A (446 cycles), the patients received dydrogesterone in the group B (439 cycles), and the patients received a combination of progesterone vaginal sustained-release gel and dydrogesterone in the group C (1 201 cycles). The pregnancy and perinatal outcomes were compared between groups A and B, groups C and B after matching the baseline data in a ratio of 1∶1 using the propensity score matching (PSM). The effect of different luteal phase support on live birth rate was analyzed after adjusting for confounding factors affected by univariate and multivariate generalized estimating equation (GEE).Results:After PSM, there were no significant differences between groups A and B, groups C and B in human chorionic gonadotropin positive rate, clinical pregnancy rate, ectopic pregnancy rate, live birth rate in transplant cycle, incidence of low weight, macrosomia, premature delivery rate, pregnancy complication rate and incidence of birth defects (all P>0.05). GEE analysis showed that three different luteal phase support regimens were not associated with live birth rate. Conclusion:In the mNC-FET cycle, patients aged ≤35 years who chose dydrogesterone alone as luteal phase support drug, had no difference in live birth rate and perinatal outcome between progesterone soft capsules or progesterone vaginal sustained-release gel combined with dydrogesterone, but the outcome still needs to be confirmed by large sample prospective studies.

Objective:To investigate the impact of different luteal phase support protocols on pregnancy outcomes in patients aged ≤35 years undergoing modified natural cycle frozen-thawed embryo transfer (mNC-FET).Methods:A retrospective cohort study was conducted to analyze 2 086 cycles of patients aged ≤35 years who received mNC-FET cycles in Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University from January 2018 to December 2020. The cycles were divided into three groups based on luteal phase support protocols used. The patients received a combination of progesterone soft capsule and dydrogesterone in the group A (446 cycles), the patients received dydrogesterone in the group B (439 cycles), and the patients received a combination of progesterone vaginal sustained-release gel and dydrogesterone in the group C (1 201 cycles). The pregnancy and perinatal outcomes were compared between groups A and B, groups C and B after matching the baseline data in a ratio of 1∶1 using the propensity score matching (PSM). The effect of different luteal phase support on live birth rate was analyzed after adjusting for confounding factors affected by univariate and multivariate generalized estimating equation (GEE).Results:After PSM, there were no significant differences between groups A and B, groups C and B in human chorionic gonadotropin positive rate, clinical pregnancy rate, ectopic pregnancy rate, live birth rate in transplant cycle, incidence of low weight, macrosomia, premature delivery rate, pregnancy complication rate and incidence of birth defects (all P>0.05). GEE analysis showed that three different luteal phase support regimens were not associated with live birth rate. Conclusion:In the mNC-FET cycle, patients aged ≤35 years who chose dydrogesterone alone as luteal phase support drug, had no difference in live birth rate and perinatal outcome between progesterone soft capsules or progesterone vaginal sustained-release gel combined with dydrogesterone, but the outcome still needs to be confirmed by large sample prospective studies.

Objective:To investigate the embryo transfer strategies of early follicular phase prolonged protocol, to reduce the risk of multiple birth rate while achieving a higher live birth rate.Methods:It was a retrospective cohort study. Patients who underwent gonadotropin-releasing hormone (GnRH) agonist protocols in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to February 2019 were included. According to the type of embryos transferred, we divided all cycles into four groups, fresh cycle cleavage stage embryo transfer group (group A), fresh cycle blastocyst transfer group (group B), freeze-thaw cleavage stage embryo transfer group (group C), freeze-thaw blastocyst transfer group (group D). The main outcome measures were live birth rate and multiple birth rate. Binary logistic regression was used to correct confounding factors.Results:The risk of moderate to severe ovarian hyperstimulation syndrome (OHSS) in group A [4.8% (110/2283)] was higher than that in group C [1.0% (6/614), P<0.001] and group D [2.1% (16/762), P<0.001]. The risk of moderate to severe OHSS in group B [3.8% (42/1116)] was higher than that in group C ( P<0.001). The multiple birth rate of the two embryos transfer group [group A 23.4% (535/2283), group C 20.8% (128/614) ] was significantly higher than that of the one blastocyst transfer group [group B 1.4% (16/1116), group D 0.9% (7/762)], and the difference was statistically significant ( P<0.001). The clinical pregnancy rate [68.7% (767/1116)] and the live birth rate [59.6% (665/1116)] of group B were higher than those of group A [63.5% (1449/2283), P=0.003; 54.8% (1250/2283), P=0.008], group C [60.1% (369/614), P<0.001; 51.6% (317/614), P=0.001] and group D [62.7% (478/762), P=0.007; 52.8% (402/762), P=0.003], but there was no statistical difference among group A, group C and group D. Taking group B as a reference, the live birth rate of group A (a OR=0.86, 95% CI=0.74-0.99, P=0.044), group C (a OR=76, 95% CI=0.62-0.93, P=0.008) and group D (a OR=0.79, 95% CI=0.65-0.95, P=0.013) was lower than that of group B. Conclusion:For the early follicular phase prolonged protocol, based on the control of OHSS, fresh cycle single blastocyst transplantation is preferred. While obtaining a higher live birth rate, the multiple birth rate is significantly reduced.

Objective:To investigate the embryo transfer strategies of early follicular phase prolonged protocol, to reduce the risk of multiple birth rate while achieving a higher live birth rate.Methods:It was a retrospective cohort study. Patients who underwent gonadotropin-releasing hormone (GnRH) agonist protocols in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to February 2019 were included. According to the type of embryos transferred, we divided all cycles into four groups, fresh cycle cleavage stage embryo transfer group (group A), fresh cycle blastocyst transfer group (group B), freeze-thaw cleavage stage embryo transfer group (group C), freeze-thaw blastocyst transfer group (group D). The main outcome measures were live birth rate and multiple birth rate. Binary logistic regression was used to correct confounding factors.Results:The risk of moderate to severe ovarian hyperstimulation syndrome (OHSS) in group A [4.8% (110/2283)] was higher than that in group C [1.0% (6/614), P<0.001] and group D [2.1% (16/762), P<0.001]. The risk of moderate to severe OHSS in group B [3.8% (42/1116)] was higher than that in group C ( P<0.001). The multiple birth rate of the two embryos transfer group [group A 23.4% (535/2283), group C 20.8% (128/614) ] was significantly higher than that of the one blastocyst transfer group [group B 1.4% (16/1116), group D 0.9% (7/762)], and the difference was statistically significant ( P<0.001). The clinical pregnancy rate [68.7% (767/1116)] and the live birth rate [59.6% (665/1116)] of group B were higher than those of group A [63.5% (1449/2283), P=0.003; 54.8% (1250/2283), P=0.008], group C [60.1% (369/614), P<0.001; 51.6% (317/614), P=0.001] and group D [62.7% (478/762), P=0.007; 52.8% (402/762), P=0.003], but there was no statistical difference among group A, group C and group D. Taking group B as a reference, the live birth rate of group A (a OR=0.86, 95% CI=0.74-0.99, P=0.044), group C (a OR=76, 95% CI=0.62-0.93, P=0.008) and group D (a OR=0.79, 95% CI=0.65-0.95, P=0.013) was lower than that of group B. Conclusion:For the early follicular phase prolonged protocol, based on the control of OHSS, fresh cycle single blastocyst transplantation is preferred. While obtaining a higher live birth rate, the multiple birth rate is significantly reduced.