Educational Inequalities in Small for Gestational Age Birth Over Time: Influence of Outcome Misclassification

ObjectivesTo investigate socioeconomic inequalities, using maternal educational attainment, maternal and partner employment status, and lone motherhood indicators, in the risk of small-for-gestational-age (SGA) births, their time trend, potential mediation by maternal smoking and body mass index, and effect modification by parity.DesignPopulation-based birth cohort using routine antenatal healthcare data.SettingBabies born at University Hospital Southampton, UK, between 2004 and 2016.Participants65 909 singleton live births born to mothers aged ≥18 years between 24-week and 42-week gestation.Main outcome measuresSGA (birth weight <10th percentile for others born at the same number of completed weeks compared with 2013/2014 within England and Wales).ResultsBabies born to mothers educated up to secondary school level (adjusted OR (aOR) 1.32, 99% CI 1.19 to 1.47), who were unemployed (aOR 1.27, 99% CI 1.16 to 1.38) or with unemployed partners (aOR 1.27, 99% CI 1.13 to 1.43), were at greater risk of being SGA. There was no statistically significant change in the magnitude of this risk difference by these indicators over time between 2004 and 2016, as estimated by linear interactions with year of birth. Babies born to lone mothers were not at higher risk compared with partnered mothers after adjusting for maternal smoking (aOR 1.05, 99% CI 0.93 to 1.20). The inverse association between maternal educational attainment and SGA risk appeared greater in multiparous (aOR 1.40, 99% CI 1.10 to 1.77) compared with primiparous women (aOR 1.28, 99% CI 1.12 to 1.47), and the reverse was true for maternal and partner’s unemployment where the association was stronger in primiparous women.ConclusionsSocioeconomic inequalities in SGA risk by educational attainment and employment status are not narrowing over time, with differences in association strength by parity. The greater SGA risk in lone mothers was potentially explained by maternal smoking. Preventive interventions should target socially disadvantaged women, including preconception and postpartum smoking cessation to reduce SGA risk.

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Exploring the Relationships in Prenatal Weight Gain, Birth Outcomes, and Postnatal Growth up to 2 Years of Age Using a Longitudinal Cohort in Niger

Current Developments in Nutrition ◽

10.1093/cdn/nzaa054_093 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 1021-1021

Author(s):

Kristin Kohlmann ◽

Ousmane Guindo ◽

Issaka Soumana ◽

Rebecca Grais ◽

Sheila Isanaka

Keyword(s):

Weight Gain ◽

Birth Weight ◽

Low Birth Weight ◽

Birth Outcomes ◽

Gestational Age ◽

Small For Gestational Age ◽

Postnatal Growth ◽

Adverse Birth Outcomes ◽

The Relationship ◽

Over Time

Abstract Objectives The first 1000 days of life, from conception until a child's second birthday, is a crucial period during which life-long foundations for good health, growth, and development are established. It has been shown that poor maternal weight gain can contribute to adverse birth outcomes, such as low birth weight, small for gestational age, and prematurity, and such adverse birth outcomes can place children at greater risk for developing wasting and stunting as they age. While it has been suggested that the development of wasting and stunting may be related, the relative impact of poor birth outcomes on weight and height attainment over time is not clear. The objective of this study is to use recently collected longitudinal data to explore the inter-relationships between prenatal weight gain, birth outcomes, and postnatal risk of both wasting and stunting over time. Methods Using longitudinal data nested within a large randomized trial conducted in Madarounfa, Niger, we describe prenatal weight gain, the risk of adverse birth outcomes (preterm, small for gestational age, and low birthweight) and postnatal child growth (weight and length/height) up to 2 years of age. We use binomial regression to examine the relationship between prenatal weight gain and adverse birth outcomes. We use generalized estimating equations to examine the risk of wasting and stunting over time and evaluate potential effect modification of postnatal growth by birth outcomes. Results We followed 2796 mother-child pairs from pregnancy through 2 years of age. We found that 55.9% of the children were born preterm, 6.4% were born small for gestational weight, and 6.8% were born with low birth weight. Using longitudinal analysis, we are examining the relationship between the risk of wasting and stunting over time. Conclusions This analysis will provide evidence to describe the inter-relationships between prenatal weight gain, adverse birth outcomes, and risk of both wasting and stunting over time, with special attention to the inter-relationships between prenatal and postnatal growth. Funding Sources Médecins Sans Frontières-Operational Center Geneva and the Kavli Foundation, Norway.

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