Maternal Risk Factors for Small-for-Gestational-Age Newborns in Mexico: Analysis of a Nationwide Representative Cohort

Background: Small for gestational age (SGA) is a key contributor to premature deaths and long-term complications in life. Improved characterization of maternal risk factors associated with this adverse outcome is needed to inform the development of interventions, track progress, and reduce the disease burden. This study aimed to identify socioeconomic, demographic, and clinical factors associated with SGA in Mexico.

Methods: We analyzed administrative data from 1,841,477 singletons collected by the National Information Subsystem of Livebirths during 2017. Small-for-gestational-age was defined as being <10^th centiles according to the INTERGROWTH-21^st standards. The comparison group was defined as being in ≥10^th centiles. We fitted logistic regression models to determine odds ratios for the maternal factors associated with SGA.

Results: Among the 1,841,477 singletons, 51% were male, 6.7% were SGA, 6.1% were term-SGA, and 0.5% were preterm-SGA. Maternal education presented a protective gradient of being SGA among mothers who achieved 1 to 6 years of education (adjusted odds ratio (aOR)0.95; 95% CI:0.91,0.99), 7 to 9 years (aOR 0.86; 95% CI:0.83,0.89), 10 to 12 years (aOR 0.75; 95% CI: 0.72, 0.79) and > 12 years (aOR 0.63; 95% CI:0.6,0.66) compared with those without education. SGA was particularly likely to occur among primiparous (aOR 1.42; 95% CI: 1.39, 1.43), mothers living in very high deprivation localities (aOR 1.39; 95% CI: 1.36, 1.43), young (aOR 1.04; 95% CI: 1.02, 1.06), advanced age (aOR 1.14; 95% CI 1.09, 1.19), and mothers living in areas above 2,000 m (aOR 1.69; 95% CI: 1.65, 1.73). Antenatal care was associated with a reduced risk of SGA by 30% (aOR 0.7; 95% CI:0.67,0.73), 23% (OR 0.77; 95% CI:0.74,0.8), and 21% (OR 0.79; 95% CI:0.75,0.83), compared with those mothers who never received antenatal care, when women visited the clinic at the first, second and third trimester, respectively.

Conclusion: Almost 7% of live births were found to be SGA. Parity, maternal age, education, place of residence, and social deprivation were significantly associated with this outcome. Antenatal care was protective. These findings imply that interventions focusing on early and adequate contact with health care facilities, reproductive health counseling, and maternal education should reduce SGA in Mexico.

Impact of Low Maternal Education on Early Childhood Overweight and Obesity in Europe

BACKGROUND

Comparable evidence on adiposity inequalities in early life is lacking across a range of European countries. This study investigates whether low maternal education is associated with overweight and obesity risk in children from distinct European settings during early childhood.

METHODS

Prospective data of 45 413 children from 11 European cohorts were used. Children's height and weight obtained at ages 4-7 years were used to assess prevalent overweight and obesity according to the International Obesity Task Force definition. The Relative/Slope Indices of Inequality (RII/SII) were estimated within each cohort and by gender to investigate adiposity risk among children born to mothers with low education as compared to counterparts born to mothers with high education. Individual-data meta-analyses were conducted to obtain aggregate estimates and to assess heterogeneity between cohorts.

RESULTS

Low maternal education yielded a substantial risk of early childhood adiposity across 11 European countries. Low maternal education yielded a mean risk ratio of 1.58 (95% confidence interval (CI) 1.34, 1.85) and a mean risk difference of 7.78% (5.34, 10.22) in early childhood overweight, respectively, measured by the RII and SII. Early childhood obesity risk by low maternal education was as substantial for all cohorts combined (RII = 2.61 (2.10, 3.23)) and (SII = 4.01% (3.14, 4.88)). Inequalities in early childhood adiposity were consistent among boys, but varied among girls in a few cohorts.

CONCLUSIONS

Considerable inequalities in overweight and obesity are evident among European children in early life. Tackling early childhood adiposity is necessary to promote children's immediate health and well-being and throughout the life course.