Clinical study on related factors of premature birth of single pregnancy after in vitro fertilization and embryo transfer

Abstract

Objective To investigate the related factors of preterm birth and neonatal outcomes in single pregnancy after in vitro fertilization and embryo transfer (IVF-ET). Method A retrospective analysis was conducted in 250 pregnant women in the Sun Yat-sen Memorial Hospital from August 2013 to August 2015. The patients were divided into preterm birth of single pregnancy after IVF-ET (group A, 50 cases), preterm birth of single pregnancy after natural pregnancy (group B, 100 cases) and full-term birth of single pregnancy after IVF-ET (group C, 100 cases). By recording the incidence of gestational diabetes mellitus, gestational hypertension, premature rupture of membranes, placenta praevia or low-positioned placenta, as well as neonatal outcome, analyze the factors related to preterm delivery of single pregnancy after IVF-ET. Results There were no significant differences in pregnancy complications, birth weight of premature infants and gestational weeks between group A and group B. The incidences of gestational hypertension in group A and group C were (14% and 3%), premature rupture of membranes (42% and 14%), placenta praevia or low-positioned placenta (12% and 2%), birth weight of newborn [(2225±622) g and (3231±482) g], 1 min Apgar score [(8.61±1.77) and (9.49±0.94)], 5 min Apgar score [(9.66±0.94) and (9.93±0.29)], and the differences between the two groups were statistically significant (P<0.05). Logistic regression analysis showed that gestational hypertension, premature rupture of membranes, placenta praevia or low-positioned placenta, cervical incompetence were associated with preterm birth of single pregnancy after IVF-ET. The incidences of cervical cerclage in pregnancies due to cervical incompetence were 22%, 9% and 4% in group A, group B and group C, respectively. There were significant difference between group A and group B, group C (P<0.05), respectively. Conclusions Gestational hypertension, premature rupture of membranes, placenta praevia or low-positioned placenta and cervical incompetence are high risk factors for preterm birth of single pregnancy after IVF-ET. The birth weight, Apgar score at 1 min and 5 min were all worse in preterm infants than in full term infants of single pregnancy after IVF-ET. Key words: Reproductive techniques, assisted; Premature birth; Pregnancy complications; Uterine cervical incompetence