Delayed Childbearing and Risk of Adverse Perinatal Outcome
A Population-Based Study
- Sven Cnattingius, MD;
- Michele R. Forman, PhD;
- Heinz W. Berendes, MD, MHS;
- Leena Isotalo, MD
- From the Division of Epidemiology, Statistics and Prevention Research, National Institute of Child Health and Human Development (Drs Cnattingius, Berendes, and Isotalo), and the Cancer Prevention Studies Branch, National Cancer Institute (Dr Forman), National Institutes of Health, Bethesda, Md. Dr Cnattingius is now with the Department of Social Medicine, University Hospital, Uppsala, Sweden.
Abstract
Objective. —To investigate the effect of advancing maternal age on pregnancy outcome among healthy nulliparous women, after adjustment for demographic characteristics, smoking, history of infertility, and other medical conditions.
Design. —A population-based cohort study was conducted with prospectively collected data from the Swedish Medical Birth Register.
Patients. —Nulliparous Nordic women (N=173715), aged 20 years and above, who delivered single births at Swedish hospitals from 1983 through 1987.
Outcome Measures. —Late fetal and early neonatal death rates; rates of very low birth weight (VLBW, <1500 g), moderately low birth weight (MLBW, 1500 through 2499 g), very preterm delivery (≤32 weeks), moderately preterm delivery (33 through 36 weeks), and small-for-gestational-age (SGA) infants (<-2 SDs).
Results. —Compared with women aged 20 to 24 years, women aged 30 to 34 years had significantly higher adjusted odds ratios (ORs) of late fetal deaths (OR=1.4); VLBW (OR=1.2); MLBW (OR=1.4); very preterm birth (OR=1.2); and SGA infants (OR=1.4). Among women aged 35 to 39 years, the adjusted OR was significantly higher for VLBW (OR=1.9); MLBW (OR=1.7); very preterm birth (OR=1.7); moderately preterm birth (OR=1.2); and SGA infants (OR=1.7). Among women 40 years old and older, the adjusted OR was significantly higher for VLBW (OR=1.8); MLBW (OR=2.0); very preterm birth (OR=1.9); moderately preterm birth (OR=1.5); and SGA infants (OR=1.4).
Conclusions. —Delayed childbearing is associated with an increased risk of poor pregnancy outcomes after adjustment for maternal complications and other risk factors.
(JAMA. 1992;268:886-890)
Footnotes
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Reprint requests to Division of Epidemiology, Statistics and Prevention Research, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892 (Dr Berendes).
