Cnattingius S, Berendes H W, Forman M R
Division of Epidemiology, Statistics and Prevention Research, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
Obstet Gynecol. 1993 Apr;81(4):512-6.
To investigate whether the age-related risk of adverse pregnancy outcomes in the first birth persisted in the second birth, before and after adjusting for the influence of an adverse pregnancy outcome in the first birth and for other possible confounders.
Prospectively collected longitudinal data from the Swedish Medical Birth Registry (n = 210,735 women) were analyzed to contrast the effects of maternal age at the first birth on the risk of adverse pregnancy outcomes in the first and second successive births.
Rates of adverse pregnancy outcomes were substantially higher in first than in second births. Compared with women aged 20-24, women aged 30-34 years had significantly higher odds ratios (ORs) of late fetal death (OR 1.4) and early neonatal death (OR 1.4) for the first but not for second births; women aged 35+ had a significantly higher OR of late fetal death (OR 2.2) for the first but not for second births. Women over 35 also had a significantly higher OR of early neonatal death for the first birth (OR 2.8) and less of an increase for second births (OR 1.8), a higher OR of low birth weight (LBW) for the first (OR 1.5) and second births (OR 1.6), and a higher OR of preterm birth for the first (OR 1.4) and second births (OR 1.7). Despite the strong tendency to repeat an adverse pregnancy outcome in second births, the age-related ORs did not change with adjustment for the previous pregnancy outcome.
Women aged 30+ at their first births have increased risks of adverse pregnancy outcomes in first births. However, second births showed no age-related increase in late fetal death and a smaller increase in early neonatal death. Increased risks for LBW and preterm birth were similar for first and second births of delayed childbearers.
在调整首次分娩不良妊娠结局的影响及其他可能的混杂因素前后，研究首次分娩时与年龄相关的不良妊娠结局风险在第二次分娩时是否依然存在。
对前瞻性收集自瑞典医学出生登记处的纵向数据（n = 210,735名女性）进行分析，以对比首次分娩时母亲年龄对首次及连续第二次分娩不良妊娠结局风险的影响。
首次分娩的不良妊娠结局发生率显著高于第二次分娩。与20 - 24岁的女性相比，30 - 34岁的女性在首次分娩时发生晚期胎儿死亡（比值比[OR] 1.4）和早期新生儿死亡（OR 1.4）的几率显著更高，但在第二次分娩时并非如此；35岁及以上的女性在首次分娩时发生晚期胎儿死亡的OR显著更高（OR 2.2），但第二次分娩时并非如此。35岁以上的女性在首次分娩时发生早期新生儿死亡的OR也显著更高（OR 2.8），而在第二次分娩时升高幅度较小（OR 1.8），首次分娩时低出生体重（LBW）的OR更高（OR 1.5），第二次分娩时也较高（OR 1.6），首次分娩时早产的OR更高（OR 1.4），第二次分娩时也较高（OR 1.7）。尽管第二次分娩时有强烈的重复不良妊娠结局的倾向，但在调整先前妊娠结局后，与年龄相关的OR并未改变。
首次分娩时年龄在30岁及以上的女性，首次分娩时不良妊娠结局的风险增加。然而，第二次分娩时晚期胎儿死亡没有与年龄相关的增加，早期新生儿死亡的增加幅度较小。晚育女性的首次和第二次分娩中，低出生体重和早产的风险增加相似。
