The Association of Maternal Age with Birthweight and Gestational Age: A Cross‐Cohort Comparison
Year: 2014
Type: article
Abstract: BACKGROUND: We examined the associations of maternal age with low birthweight (LBW) and preterm birth in four cohorts from a middle- and a high-income country, where the patterning of maternal age by socio-economic position (SEP) is likely to differ. METHODS: Population-based birth cohort studies were carried out in the city of Pelotas, Brazil in 1982, 1993, and 2004, and in Avon, UK in 1991 [Avon Longitudinal Study of Parents and Children (ALSPAC)]. Adjustment for multiple indicators of SEP were applied. RESULTS: Low SEP was associated with younger age at childbearing in all cohorts, but the magnitudes of these associations were stronger in ALSPAC. Inverse associations of SEP with LBW and preterm birth were observed in all cohorts. U-shaped associations were observed between maternal age and odds of LBW in all cohorts. After adjustment for SEP, increased odds of LBW for young mothers (<20 years) attenuated to the null but remained or increased for older mothers (≥ 35 years). Very young (<16 years) maternal age was also associated with both outcomes even after full SEP adjustment. SEP adjusted odds ratio of having a LBW infant in women <16 years and ≥ 35 years, compared with 25-29 years, were 1.48 [95% confidence interval (CI) 1.00, 2.20] and 1.66 [95% CI 1.36, 2.02], respectively. The corresponding results for preterm birth were 1.80 [95% CI 1.23, 2.64)] and 1.38 [95% CI 1.15, 1.67], respectively. CONCLUSION: Confounding by SEP explains much of the excess risk of LBW and preterm among babies born to teenage mothers as a whole, but not for mothers aged <16 or ≥ 35 years. Given that the proportion of women becoming pregnant at <16 years is smaller than for those ≥ 35 years, the population burden is greater for older age.
DOI: 10.1111/ppe.12162
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,770
Funders: World Health Organization, Wellcome Trust, Universidade Federal de Pelotas, International Development Research Centre, National Institute for Health and Care Research, European Commission, University of Bristol, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Ministério da Saúde, Medical Research Council
Awards: NIHR Senior Investigator Award, G235045266, G4182683118, The Avon Longitudinal Study for Parents and Children: An international resource for population genomic and lifecourse epidemiology. Core programme support 2014-2019., The Avon Longitudinal Study of Parents and Children: An international resource for population
genomics and lifecourse epidemiology. Core Programme Support 2011-2015 and Core programme support 2014-2019, The Avon Longitudinal Study of Parents and Children: An international resource for population genomics and lifecourse epidemiology. Core Programme Support 2011-2013., G6737906592, G6955841523, G6986701655, G7407801207
OpenAlex ID: W1543840653