The associations of parity and maternal age with small-for-gestational-age, preterm, and neonatal and infant mortality: a meta-analysis
Kozuki, N.; Lee, A.C.C.; Silveira, M.F.; Sania, A.; Vogel, J.P.; Adair, L.; Barros, F.; Caulfield, L.E.; Christian, P.; Fawzi, W.; Humphrey, J.; Huybregts, L.; Mongkolchati, A.; Ntozini, R.; Osrin, D.; Roberfroid, D.; Tielsch, J.; Vaidya, A.; Black, R.E.; Katz, J.
Bmc Public Health 13 Suppl. 3: S2
2013
ISSN/ISBN: 1471-2458 PMID: 24564800 DOI: 10.1186/1471-2458-13-s3-s2Document Number: 641563
Previous studies have reported on adverse neonatal outcomes associated with parity and maternal age. Many of these studies have relied on cross-sectional data, from which drawing causal inference is complex. We explore the associations between parity/maternal age and adverse neonatal outcomes using data from cohort studies conducted in low- and middle-income countries (LMIC). Data from 14 cohort studies were included. Parity (nulliparous, parity 1-2, parity ≥ 3) and maternal age (<18 years, 18-<35 years, ≥ 35 years) categories were matched with each other to create exposure categories, with those who are parity 1-2 and age 18-<35 years as the reference. Outcomes included small-for-gestational-age (SGA), preterm, neonatal and infant mortality. Adjusted odds ratios (aOR) were calculated per study and meta-analyzed. Nulliparous, age <18 year women, compared with women who were parity 1-2 and age 18-<35 years had the highest odds of SGA (pooled adjusted OR: 1.80), preterm (pooled aOR: 1.52), neonatal mortality (pooled aOR: 2.07), and infant mortality (pooled aOR: 1.49). Increased odds were also noted for SGA and neonatal mortality for nulliparous/age 18-<35 years, preterm, neonatal, and infant mortality for parity ≥ 3/age 18-<35 years, and preterm and neonatal mortality for parity ≥ 3/≥ 35 years. Nulliparous women <18 years of age have the highest odds of adverse neonatal outcomes. Family planning has traditionally been the least successful in addressing young age as a risk factor; a renewed focus must be placed on finding effective interventions that delay age at first birth. Higher odds of adverse outcomes are also seen among parity ≥ 3 / age ≥ 35 mothers, suggesting that reproductive health interventions need to address the entirety of a woman's reproductive period. Funding was provided by the Bill & Melinda Gates Foundation (810-2054) by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group.