Changes in maternal age and its influences on maternal and neonatal complications under the two-child policy / 中华围产医学杂志

ABSTRACT

Objective To explore the changes in gravida's age and its influences on maternal and neonatal complications under China's two-child policy.Methods This study retrospectively analyzed the clinical data such as adverse gestational complications and fetal condition of 42 771 gravidas delivering at Changzhou Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University from July 2013 to December 2017.According to their age at delivery,they were divided into three groupsthe younger maternal age group (1 140 cases,＜20 years),the advanced maternal age group (4 307 cases,≥ 35 years) and the median maternal age group (37 324 cases,≥ 20 and ＜35 years).Chi-square test was used to compare the differences among groups.Cochran-Armitage test was used for trend analysis.The risks of various complications in younger and advanced maternal age groups were analyzed by binary logistic regression analysis.Results (1) The proportion of advanced maternal age pregnancies tended to rise gradually year by year (Z=-9.909,P＜0.001).However,the figure of younger gravidas remained low and presented a downward trend (Z=10.685,P＜0.001).(2) The incidence of pregnant complications in the younger,advanced and the median maternal age groups were 52.8％ (602/1 140),72.3％ (3 116/4 307) and 56.5％ (21 091/37 324),respectively.Compared with the median maternal age group,the advanced maternal age group was at greater risks of premature delivery [9.0％ (3 343/37 324) vs 11.6％ (499/4 307),x2=124.233,P＜0.001],fetal growth restriction (FGR) [0.6％ (218/37 324) vs 1.2％ (50/4 307),x2=20.087,P＜0.001],postpartum hemorrhage [5.7％ (2 120/37 324) vs 7.8％ (336/4 307),x2=31.299,P＜0.05],hypertensive disorders in pregnancy(HDP) [4.2％ (1 561/37 324) vs 8.7％ (376/4 307),x2=180.013,P＜0.001],gestational diabetes mellitus (GDM) [7.6％ (2 845/37 324) vs 15.1％ (650/4 307),x2=280.126,P＜0.001]and placenta previa [1.7％ (621/37 324) vs 3.8％ (165/4 307),x2=97.904,P＜0.001],and the younger maternal age group was at greater risks of HDP [4.2％ (1 561/37 324) vs 5.9％ (67/1 140),x2=4.234,P=0.040],fetal distress [3.5％ (1 325/37 324) vs 5.1％ (58/1 140),x2=7.546,P=0.006],premature delivery [9.0％ (3 343/37 324) vs 15.0％ (171/1 140),22=48.668,P＜0.001] and FGR [0.6％ (218/37 324) vs 1.1％ (12/1 140),x2=4.086,P=0.043].(3) Gestational complications in the younger maternal age group were mainly related to the fetuses such as premature rupture of membranes (PROM) and premature delivery,while the advanced maternal age group had a higher incidence of maternal complications,especially GDM and HDP.(4) Most of the gravidas of advanced maternal age with HDP developed severe preeclampsia (47.9％,180/376),while mild preeclampsia was dominant in the median maternal aged HDP women (45.4％,708/1 561).(5) The advanced maternal age group had higher risk of stillbirth,premature delivery,FGR,placenta previa,GDM,HDP and postpartum hemorrhage [OR(95％CI)1.91 (1.29-2.84),1.33 (1.21-1.46),1.66 (1.21-2.28),2.56 (2.15-3.04),2.39 (2.19-2.61),2.36 (2.11-2.65),1.46 (1.31-1.62);all P＜0.05],but lower risks of fetal distress and PROM [OR(95％CI)0.79 (0.65-0.95) and 0.88 (0.81-0.96);both P＜0.05].The younger maternal age group had a higher risk of premature delivery [OR(95％CI)1.97 (1.61-2.40);P＜0.001],but significant lower risks of PROM and GDM [OR(95％CI)0.77 (0.62-0.95) and 0.05 (0.02-0.16);both P＜0.05].Conclusions Maternal age is closely related to the adverse outcomes of pregnancy.Two-child policy in China will bring about changes in maternal age and composition of pregnant complications.