Maternal Blood Pressure in Relation to Prenatal Lipid-Based Nutrient Supplementation and Adverse Birth Outcomes in a Ghanaian Cohort: A Randomized Controlled Trial and Cohort Analysis

Abstract

Background: It is unknown whether prenatal lipid-based nutrient supplements (LNSs) affect blood pressure (BP). Associations between hypertension and birth outcomes using recently updated BP cutoffs are undetermined.

Objectives: We aimed to assess the impact of LNSs on maternal hypertension and associations between hypertension and birth outcomes.

Methods: Pregnant Ghanaian women at ≤20 weeks of gestation (n = 1320) were randomly assigned to receive daily 1) iron and folic acid (IFA), 2) multiple micronutrients (MMN), or 3) LNSs until delivery. BP was measured at enrollment and 36 weeks of gestation. We analyzed the effect of LNSs on BP using ANOVA and associations between hypertension [systolic BP (SBP) ≥130 mm Hg or diastolic BP (DBP) ≥80 mm Hg] and birth outcomes by linear and logistic regressions.

Results: Mean ± SD SBP and DBP were 110 ± 11 and 63 ± 8 mm Hg at 36 weeks of gestation and did not differ by supplementation group (SBP, P > 0.05; DBP, P > 0.05). At enrollment, higher DBP was associated with lower birth weight and shorter gestation; women with high DBP had greater risk of low birth weight (LBW) [risk ratio (RR): 2.58; 95% CI: 1.09, 6.08] and preterm birth (PTB) (RR: 3.30; 95% CI: 1.47, 7.40). At 36 weeks of gestation, higher SBP was associated with lower birth weight, length, and head circumference and shorter gestation; higher DBP was associated with lower birth weight and length; and women with high DBP had greater risk of LBW (RR: 3.39; 95% CI: 1.32, 8.69). Neither high SBP nor hypertension were associated with birth outcomes at either time point.

Conclusions: Daily provision of LNSs does not affect maternal hypertension, compared with IFA and MMN. Higher SBP and DBP are associated with a shorter gestation and smaller birth size; however, only high DBP is associated with LBW and PTB. The new BP cutoffs may help identify pregnancies at risk of adverse birth outcomes.This trial was registered at clinicaltrials.gov as NCT00970866.

Keywords: Ghana; birth outcomes; low birth weight; maternal blood pressure; maternal hypertension; prenatal supplements; preterm birth.

FIGURE 1

Study profile. The IFA group received 60 mg iron plus 400 mg folic acid. The MMN group received 1–2 Recommended Dietary Allowances of 18 vitamins and minerals (including 20 mg iron). The LNS group received LNS with the same micronutrients as the MMN group, plus another 4 minerals (Ca, P, K, and Mg), as well as macronutrients. All 3 supplements were intended for daily consumption. ¹During the study, IFA and MMN capsules were unintentionally mislabeled, causing 92 participants in the IFA group and 85 participants in the MMN group to receive the incorrect supplement. A total of 86 women not-exposed in the LNS group, as well as the mixed-exposure women in the IFA or MMN groups were excluded.