Maternal risk exposure during pregnancy and infant birth weight

Preconception paternal/maternal BMI and risk of small/large for gestational age infant in over 4·7 million Chinese women aged 20-49 years: a population-based cohort study in China

Evidence of couples' BMI and its influence on birth weight is limited and contradictory. Therefore, this study aims to assess the association between couple's preconception BMI and the risk of small for gestational age (SGA)/large for gestational age (LGA) infant, among over 4·7 million couples in a retrospective cohort study based on the National Free Pre-pregnancy Checkups Project between 1 December 2013 and 30 November 2016 in China. Among the live births, 256 718 (5·44 %) SGA events and 506 495 (10·73 %) LGA events were documented, respectively. After adjusting for confounders, underweight men had significantly higher risk (OR 1·17 (95 % CI 1·15, 1·19)) of SGA infants compared with men with normal BMI, while a significant and increased risk of LGA infants was obtained for overweight and obese men (OR 1·08 (95 % CI 1·06, 1·09); OR 1·19 (95 % CI 1·17, 1·20)), respectively. The restricted cubic spline result revealed a non-linear decreasing dose-response relationship of paternal BMI (less than 22·64) with SGA. Meanwhile, a non-linear increasing dose-response relationship of paternal BMI (more than 22·92) with LGA infants was observed. Moreover, similar results about the association between maternal preconception BMI and SGA/LGA infants were obtained. Abnormal preconception BMI in either women or men were associated with increased risk of SGA/LGA infants, respectively. Overall, couple's abnormal weight before pregnancy may be an important preventable risk factor for SGA/LGA infants.

Poor maternal anthropometric characteristics and newborns' birth weight and length: a cross-sectional study in Benin

Background

Maternal undernutrition is known to negatively impact newborns' birth weight and length, but this finding is poorly documented in the Beninese population. This study aimed to assess the effect of maternal anthropometry on mean birth weight and length in a Beninese cohort of newborns.

Methods

A cross-sectional study was carried out in Tori Bossito, Republic of Benin. Pregnant women attending maternity wards between June 2007 and July 2008 were recruited. At delivery the women's characteristics, including weight and height, were gathered and newborns' birth weights and lengths were measured. Statistical analysis was performed using multiple linear regression.

Results

A total of 526 mother-infant pairs were enrolled; 29.8% of women had low weight status and 26.2% had short stature (<155 cm). The mean birth weight was 2985 g (standard deviation [SD] 384) the mean birth length was 48.7 cm (SD 2.2). Maternal low weight status (coefficient=-151.81, p<0.001) and short stature (coefficient=-135.49, p<0.001) reduced the mean birth weight. Similar results were found for mean birth length, which was decreased by maternal low weight status (coefficient=-0.42, p=0.04) and short stature (coefficient=-0.51, p=0.01).

Conclusion

Maternal undernutrition expressed by low anthropometry remains problematic in the Beninese population and induces transmission of malnutrition. Nutritional interventions are required to break this vicious cycle.

Estimating the pathways through which maternal education affects stunting: evidence from an urban cohort in South Africa

OBJECTIVE

To estimate the determinants of stunting using rich data from a birth cohort study from urban South Africa and to examine the various mechanisms, both proximate and distal, through which maternal education affects stunting.

DESIGN

Multivariate regression analysis using birth cohort data, where the outcome variable was stunting at age 2 years, and multiple mediator analysis to identify pathways from maternal education to stunting.

SETTING

South Africa's largest metropolitan area, Soweto-Johannesburg.

SUBJECTS

Participants of Birth to Twenty Plus, a longitudinal cohort study of children born in 1990 (n 691).

RESULTS

In multivariate analysis, the birth weight Z-score (-0·084; P<0·001; 95 % CI -0·11, -0·06), the mother's openness towards modern health care, captured by a vaccination score (-0·05; P=0·04; 95 % CI -0·10, -0·00), and a better-quality care environment (-0·015; P=0·04; 95 % CI -0·03, -0·00) were found to be negatively associated with stunting. Having experienced symptoms of illness related to ears and eyes increased the risk of stunting (0·038; P=0·01; 95 % CI 0·01, 0·07). Results of the mediation analysis showed that maternal education had an indirect effect on stunting largely through socio-economic status and the antenatal environment (measured by the birth weight Z-score).

CONCLUSIONS

Overall, many of the factors that were protective against stunting in the final analysis, whether they operated through maternal education or not, were related to the mother's contribution to the child's life. This reinforces the idea that to minimise stunting, enhanced antenatal and postnatal services to better support and empower mothers may be important.