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

Abstract

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 <10th centiles according to the INTERGROWTH-21st standards. The comparison group was defined as being in ≥10th 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.

National data linkage assessment of live births and deaths in Mexico: Estimating under‐five mortality rate ratios for vulnerable newborns and trends from 2008 to 2019

“…Every year, pseudonymised and validated datasets of live births and deaths are published online separately 11,12 . Given that most live births and deaths occurred in healthcare facilities, national coverage has been estimated to reach more than 90.0% of the target population, but this percentage varies at the subnational level 17,18 …”

Comparison of growth patterns in the first year of life between term small for gestational age and appropriate for gestational age South Indian infants

“…Downloaded from Open access these infants to higher risk of insulin resistance, obesity, dyslipidaemia and hypertension in adulthood. [4][5][6] SGA infants often experience early-life catch-up growth (CUG). CUG is described as the upward crossing of centiles observed in infants born low birth, 7 and also defined as an increase in Z score of >0.67 between twotime points.…”

Socio-economic differences among low-birthweight infants in Hungary. Results of the Cohort ‘18 –Growing Up in Hungary birth cohort study

“…smoking, drug consumption, or exposure to toxic substances [13,14]), inadequate prenatal care or socioeconomic risk factors [15]. The latter includes maternal educational attainment [11][12][16][17][18][19][20], maternal age [12,[21][22][23], ethnicity [11,[24][25][26] and marital status [20]. Social inequalities in health thus appear in the very earliest stages of life [27][28][29].…”

“…Birth weight can be also related to ethnicity. Based on the UK Millennium Cohort Study (MCS), [21] Indian, Pakistani, Bangladeshi, Black Caribbean and Black African infants were more likely to be low birthweight compared to White infants. Burris and Hacker [37] reported that in the USA black infants are disproportionately more likely to be born with LBW.…”