Independent and Joint Effects of Prenatal Zinc and Vitamin A Deficiencies on Birthweight in Rural Sidama, Southern Ethiopia: Prospective Cohort Study

Abstract

BackgroundThe effects of prenatal Zinc Deficiency (ZD) and Vitamin A Deficiency (VAD) on birthweight are controversial and their interaction has not been investigated.ObjectiveTo assess the independent and interaction effects of prenatal zinc and vitamin A deficiencies on birthweight in rural Sidama, Southern Ethiopia.MethodologyA community-based prospective cohort study design was employed. Six hundred fifty pregnant women in their second or third trimester were randomly selected and their serum zinc and retinol concentrations were determined. About 575 subjects were successfully followed until delivery and birthweight was measured within 72 hours after delivery. The association between the exposures and birthweight was examined using log-binomial and liner regression analyses. Potential interaction between ZD and VAD was examined using Synergy Index (SI).ResultsThe mean birthweight (± standard deviation) was 2896 g (±423). About 16.5% (95% CI: 13.5–19.6%) of the babies had Low Birthweight (LBW). Prenatal ZD and VAD were not significantly associated to LBW with Adjusted Relative Risk (ARR) of 1.25 (95 CI: 0.86–1.82) and 1.27 (95% CI: 0.86–1.87), respectively. Stratified analysis on the basis of gestational trimester showed that the occurrence of the deficiencies neither in the second nor third trimester were associated to LBW. The deficiencies did not show synergetic interaction in causing LBW [SI = 1.04 (95% CI: 0.17–6.28)]. Important risk factors of LBW were maternal illiteracy [RR = 1.80 (95% CI: 1.11–2.93)], female sex of the newborn [RR = 1.79 (95% CI: 1.19–2.67)], primiparity [RR = 1.16 (95% CI: 1.02–1.35)], short maternal stature [RR = 1.63 (95% CI: 1.06–2.51)] and maternal thinness [RR = 1.52 (95% CI: 1.03–2.25)]. In the linear regression model, elevated CRP was also negatively associated to birthweight.ConclusionLBW is of public health significance in the locality. The study did not witness any independent or interaction effect of prenatal ZD and VAD on birthweight.

Effects of Maternal Pregnancy Intention, Depressive Symptoms and Social Support on Risk of Low Birth Weight: A Prospective Study from Southwestern Ethiopia

“…In particular, birth weight is not known for rural babies and such community-based studies focusing on rural populations find higher incidence of LBW than facility-based studies [13], [14]. For instance, recent community based studies in eastern and southern Ethiopia found higher incidence of LBW of 28% and 17% respectively [15], [16]. In the 2011 Ethiopian Demographic and Health Survey, a nationally representative population-based sample, reported that 21% of all live births in rural Ethiopia in the five years preceding the survey were very small in size, as reported subjectively by the mother [17].…”

Prevalence and associated factors of zinc deficiency among pregnant women and children in Ethiopia: a systematic review and meta-analysis

“…Again, we excluded 100 duplicate records and finally we left with 19 records. After assessing the full texts of the 19 records for their eligibility, 6 records [21][22][23][24][25][26] were further excluded by the exclusion criteria. Finally, 13 studies, 7 for pregnant women [15,[27][28][29][30][31][32] and 6 for children [11,[33][34][35][36][37], were found to be eligible for this systematic review and meta-analysis ( Fig.…”

Effects of Environmental Exposures on Fetal and Childhood Growth Trajectories

“…A clinical trial reported that daily Zn supplementation in women with relatively low plasma Zn concentrations at 19 weeks gestation is associated with greater infant birth weights and head circumferences. 112 Conversely, studies using blood samples collected at birth or in late pregnancy have produced inconsistent results, with eight studies 78,114–119 showing no association and three studies 120–122 observing an increased risk between maternal serum Zn levels and risk of delivering LBW infants.…”

“…Toxic metals reaching the fetus could impair or alter the uterine environment and dysregulate the fetal epigenome, given that the embryo and fetus are highly susceptible to epigenetic dysregulation by environmental pollutants, 115,119 may affect gene expression and enzyme activity in placental trophoblast cells, 124 act as endocrine disruptors, 123,135–138 and/or develop persistent vulnerabilities in immune system function that would affect fetal development. 138,139 Trace minerals could lead to adverse health effects at too high levels.…”