RESUMO
Objective:To investigate the incidence and risk factors of neonatal asphyxia in twin pregnancy.Methods:This study retrospectively recruited 2 035 women with twin pregnancy and their 4 070 twin neonates in the Obstetrics and Gynecology Hospital of Fudan University from January 2010 to December 2018. There were 211 cases suffered from neonatal asphyxia (asphyxia group) and 3 859 did not (non-asphyxia group). The demographic information of the women and their newborns and the incidence of perinatal complications were compared between the two groups by two independent samples t-test and Chi-square test. Multivariate logistic regression was used to analyze the risk factors of neonatal asphyxia in twin pregnancy. Results:The age of 2 035 women was (31.8±4.4) years old (17-52 years old). The gestational age of the twins at delivery was (35.2±2.2) weeks (25-40 weeks). There were 1 330 (65.4%) premature births, including 997 (49.0%) born at ≥34 weeks. Monochorionic diamniotic twin pregnancies accounted for 22.6% (460/2 035). The total incidence of neonatal asphyxia was 5.2% (211/4 070), 5.0% (102/2 035) in the first- and 5.4% (109/2 035) in the second-born twin infants, and the three figures were all decreased with the increase of gestational age ( χ2trend=1 601.965, 549.693 and 1 089.709, all P<0.001) as well as birth weight ( χ2trend=1 273.386, 437.906 and 848.007, all P<0.001). Univariate analysis showed that the asphyxia group had smaller gestational age and lower birth weight [(34.1±2.8) vs (35.3±2.1) weeks, t=6.279; (2 113.3±565.7) vs (2 339.6±478.7) g, t=5.700], but a higher ratio of male infants [58.3% (123/211) vs 48.5% (1 878/3 859), χ2=7.704], vaginal delivery [10.4% (22/211) vs 4.5% (173/3 859), χ2=15.493], monochorionic diamniotic twins [27.5% (58/211) vs 22.3% (862/3 859), χ2=7.714], special complications related to monochorionic diamniotic twin pregnancies [8.1% (17/211) vs 2.5% (95/3 859), χ2=23.403] and fetal distress [13.7% (29/211) vs 3.8% (148/3 859), χ2=47.222] than the non-asphyxia group (all P<0.05). After adjusting for the gestational age, birth weight and gender, multivariate logistic regression found that vaginal delivery ( OR=1.748, 95% CI: 1.069-2.861), special complications related to monochorionic diamniotic twin pregnancies ( OR=3.200, 95% CI: 2.056-4.982) and fetal distress ( OR=2.017, 95% CI: 1.073-3.791) were the risk factors for asphyxia in twin neonates (all P<0.05). Conclusions:The incidence of neonatal asphyxia is high in twins with small gestational age and low birth weight. Vaginal delivery, fetal distress and special complications related to monochorionic diamniotic twin pregnancies are the high-risk factors. Clinicians should be well prepared for resuscitation when encountering neonatal asphyxia.