辅助生殖技术后双胎生长不一致的发生及相关因素分析

Analysis of Incidence Rate and Related Factors of Growth Discordance in Twins Conceived by Assisted Reproductive Technology

目的:分析辅助生殖技术(ART)后双胎生长不一致发生率及可能的相关因素。方法:选择2013年1月至2014年3月于天津市中心妇产科医院生殖中心行ART治疗后双胎活产461例进行分析,以双胎儿出生体重差异≥20%为诊断标准,分为生长不一致组(61例)与生长一致组(400例),比较两组间临床资料。结果:两组在母亲年龄、妊娠前母亲体重指数、移植日内膜厚度、每周期优胚移植数、原发不孕率、减胎率、同性别双胎率方面比较,差异均无统计学意义(P>0.05),但生长不一致组解冻移植率明显高于生长一致组(81.97%vs 66.75%,P=0.017),Pearson列联系数r=0.11,而且生长不一致组妊娠期并发症发生率高于生长一致组(42.62%vs 19.25%,P=0.000),Pearson列联系数r=0.19。新鲜移植患者的妊娠期并发症发生率20.83%(30/144)与解冻移植患者的妊娠期并发症发生率23.03%(73/317)比较,差异无统计学意义(P=0.600)。结论:解冻移植和妊娠期并发症可能是ART后双胎生长不一致发生的相关因素,但解冻移植并非通过增加妊娠期并发症的发生率而引起双胎生长不一致的高发生,具体机制尚需进一步研究。

Objective：To study the incidence rate and conceivable related factors of growth discordance in twins conceived by assisted reproductive technology （ART）. Methods：461 cases of live birth twin pregnancies conceived by assisted reproductive technology in the reproductive center of Tianjin central hospital of obstetrics and gynecology from January 2013 to March 2014 were studied. 61 cases with birth weight difference≥20% were defined as the discordant twins group, and the other four hundred cases with birth weight difference 〈 20% were defined as the concordant twins group. Clinical data from two groups were studied. Results：There was no significant difference （ P 〉 0. 05） with the maternal age, body mass index （BMI） of mothers before the pregnancies, endometrial thickness on embryo transfer day, number of high qualified embryo per transfer cycle, rate of primary infertility, rate of multifetal reduction, rate of same-sex twin pairs between two groups. But the rate of frozen thawed embryo transfer was obviously higher in the discordant twins group （81.97% vs 66.75%, P = 0. 017 ）, with the Pearson contingency coefficient r =0. 11. The incidence rate of pregnancy complications was prominently higher in the discordant twins group（42.62% vs 19. 25%, P = 0. 000）, with the Pearson contingency coefficient r = 0. 19. The rate of pregnancy complications in the fresh embryo transfer group and frozen thawed embryo transfer was 20.83% （30/144 ） and 23.03% （73/317 ） respectively, with no statistically significant difference （ P = 0.600 ）. Conclusions=Our study indicated that the frozen thawed embryo transfer and the incidence of pregnancy complications may be the related factors for the higher incidence rate of growth discordance in twins conceived by ART. But the higher incidence of growth discordance in twins after frozen thawed embryo transfer is not due to increasing incidence of pregnancy complications. Further study is needed to elucidate the detailed mechanism.