Objective: To investigate the impact of a previous cesarean delivery on pregnancy outcomes of in vitro fertilization and frozen-thawed embryo transfer (FET). Methods: The clinical data of 1 179 patients who received in vitro fertilization and FET in Tianjin Central Hospital of Gynecology Obstetrics from January 2014 to May 2019 and had a history of the previous delivery were retrospectively analyzed. The patients were divided into four groups according to different previous delivery history and the number of embryo transferred: group A (single embryo transfer group with cesarean delivery history, n=338), group B (single embryo transfer group with vaginal delivery history, n=78), group C (double embryo transfer group with cesarean delivery history, n=444), and group D (double embryo transfer group with vaginal delivery history, n=319). The 1∶1 propensity score based on age, body mass index (BMI), infertility duration, basal FSH, basal LH, number of oocytes retrieved and high-quality embryo rate was used to match group A and B (caliper value=0.15), group C and D (caliper value=0.05), and group A and C (caliper value=0.01) respectively to reduce the influence of selection bias. The clinical pregnancy outcomes of patients were compared. Results: (1) Group A and group B were single embryo transfer groups with a total of 77 pairs of matched patients. There were no statistically significant differences in clinical pregnancy rate [42.9% (33/77) vs 45.5% (35/77)], miscarriage rate, preterm birth rate, and neonatal birth weight (all P>0.05). (2) Group C and group D were double embryo transfer groups with a total of 304 pairs of matched patients. The clinical pregnancy rate [42.4% (129/304)] and twin pregnancy rate [9.5% (29/304)] of Group C were significantly lower than those of Group D [53.0% (161/304), 15.5% (47/304) respectively; both P<0.05). There were no statistically significant in miscarriage rate, preterm birth rate and neonatal birth weight between the two groups (all P>0.05). (3) Groups A and C matched 318 pairs of patients. The two groups had no statistical significances in clinical pregnancy rate [38.4% (122/318) vs 45.6% (145/318)], miscarriage rate and preterm birth rate (all P>0.05), but the twin pregnancy rate in group C was significantly higher than that of group A [11.3% (36/318) vs 0.3% (1/318), P<0.01). (4) The occurrence of the low-birth-weight infant were related to gestational age (OR=0.41, 95%CI: 0.32-0.54) and twin pregnancy (OR=4.44, 95%CI: 1.93-10.21), and the occurrence of macrosomia was related to BMI (OR=1.18, 95%CI: 1.06-1.32). Moreover, the previous delivery method was not related to the neonatal birth weight (P>0.05). Conclusions: Patients with different delivery histories receive FET therapy, the pregnancy outcomes of single embryo transfer are not significantly different, and the success rate of double embryo transfer in patients with a cesarean delivery history is low. The neonatal birth weight is not related to the history of the cesarean section. It is recommended that patients with a cesarean delivery history choose elective single embryo transfer to ensure the success rate and to reduce the risk.
目的： 探讨既往剖宫产史对冷冻胚胎解冻移植（FET）妊娠结局的影响。 方法： 回顾性分析天津市中心妇产科医院2014年1月至2019年5月行体外受精FET且有既往分娩史的1 179例患者的临床资料。依据既往分娩史和移植胚胎数分为4组：剖宫产史单胚组（n=338）、无剖宫产史单胚组（n=78）、剖宫产史双胚组（n=444）、无剖宫产史双胚组（n=319）。基于年龄、体质指数（BMI）、不孕年限、基础FSH、基础LH、获卵数和优质胚胎率的1∶1倾向性评分匹配剖宫产史单胚组与无剖宫产史单胚组（卡钳值=0.15）、剖宫产史双胚组与无剖宫产史双胚组（卡钳值=0.05）、剖宫产史单胚组与剖宫产史双胚组（卡钳值=0.01），以减少选择偏倚的影响。比较各组的临床妊娠结局的差异。 结果： （1）剖宫产史单胚组、无剖宫产史单胚组共匹配了77对患者，两组在临床妊娠率［分别为42.9%（33/77）、45.5%（35/77）］、流产率、早产率和新生儿出生体重方面均无差异（P均>0.05）。（2）剖宫产史双胚组、无剖宫产史双胚组匹配了304对患者，剖宫产史双胚组的临床妊娠率［42.4%（129/304）］、双胎妊娠率［9.5%（29/304）］明显低于无剖宫产史双胚组［分别为53.0%（161/304）、15.5%（47/304）］，分别比较，差异均有统计学意义（P均<0.05）；两组间的流产率、早产率和新生儿出生体重方面无差异（P>0.05）。（3）剖宫产史单胚组、剖宫产史双胚组匹配了318对患者，两组的临床妊娠率［分别为38.4%（122/318）、45.6%（145/318）］、流产率和早产率均无差异（P均>0.05），但剖宫产史双胚组的双胎妊娠率显著高于剖宫产史单胚组［分别为11.3%（36/318）、0.3%（1/318）， P<0.01］。（4）低出生体重儿与分娩孕周（OR=0.41，95%CI为0.32~0.54）和双胎妊娠（OR=4.44，95%CI为1.93~10.21）相关，巨大儿与母亲的BMI（OR=1.18，95%CI为1.06~1.32）相关；新生儿出生体重与既往分娩方式无关（P>0.05）。 结论： 不同既往分娩史的患者接受FET治疗，单胚胎移植的妊娠结局无明显差异，既往剖宫产史患者双胚胎移植的成功率低。新生儿出生体重与孕周、是否双胎、母亲BMI相关，与剖宫产史无关。建议既往剖宫产史患者选择性单胚胎移植，既可保证成功率又可降低双胎妊娠率和新生儿的风险。.