Background: Ready-to-use lipid-based nutrient supplements (LNS) are a highly nutrient-dense supplement, which could be a good source of macro- and micronutrients for pregnant women who need to supplement their nutrient intake.
Objectives: To assess the effects of LNS for maternal, birth and infant outcomes in pregnant women. Secondary objectives were to explore the most appropriate composition, frequency and duration of LNS administration.
Search methods: In May 2018, we searched CENTRAL, MEDLINE, Embase, 22 other databases and two trials registers for any published and ongoing studies. We also checked the reference lists of included studies and relevant reviews, and we contacted the authors of included studies and other experts in the field to identify any studies we may have missed, including any unpublished studies.
Selection criteria: We included randomised controlled trials (RCTs) and quasi-RCTs that compared LNS given in pregnancy to no intervention, placebo, iron folic acid (IFA), multiple micronutrients (MMN) or nutritional counselling.
Data collection and analysis: We used standard Cochrane procedures.
Main results: We included four studies in 8018 pregnant women. All four studies took place in stable community settings in low- and middle-income countries: Bangladesh, Burkina Faso, Ghana and Malawi. None were in emergency settings. The oldest trial was published in 2009. Of the four included studies, one compared LNS to IFA, one compared LNS to MMN, and two compared LNS to both IFA and MMN.We considered the included studies to be of medium to high quality, and we rated the quality of the evidence as moderate using the GRADE approach.LNS versus IFAMaternal outcomes: there was no difference between the LNS and IFA groups as regards maternal gestational weight gain per week (standard mean difference (SMD) 0.46, 95% confidence interval (CI) -0.44 to 1.36; 2 studies, 3539 participants). One study (536 participants) showed a two-fold increase in the prevalence of maternal anaemia in the LNS group compared to the IFA group, but no difference between the groups as regards adverse effects. There was no difference between the two groups for maternal mortality (risk ratio (RR) 0.53, 95% CI 0.12 to 2.41; 3 studies, 5628 participants).Birth and infant outcomes: there was no difference between the LNS and IFA groups for low birth weight (LBW) (RR 0.87, 95% CI 0.72 to 1.05; 3 studies, 4826 participants), though newborns in the LNS group had a slightly higher mean birth weight (mean difference (MD) 53.28 g, 95% CI 28.22 to 78.33; 3 studies, 5077 participants) and birth length (cm) (MD 0.24 cm, 95% CI 0.11 to 0.36; 3 studies, 4986 participants). There was a reduction in the proportion of infants who were small for gestational age (SGA) (RR 0.94, 95% CI 0.89 to 0.99; 3 studies, 4823 participants) and had newborn stunting (RR 0.82, 95% CI 0.71 to 0.94; 2 studies, 4166 participants) in the LNS group, but no difference between the LNS and IFA groups for preterm delivery (RR 0.94, 95% CI 0.80 to 1.11; 4 studies, 4924 participants), stillbirth (RR 1.14; 95% CI 0.52 to 2.48; 3 studies, 5575 participants) or neonatal death (RR 0.96, 95% CI 0.14 to 6.51). The current evidence for child developmental outcomes is not sufficient to draw any firm conclusions.LNS versus MMNMaternal outcomes: one study (662 participants) showed no difference between the LNS and MMN groups as regards gestational weight gain per week or adverse effects. Another study (557 participants) showed an increased risk of maternal anaemia in the LNS group compared to the MMN group.Birth and infant outcomes: there was no difference between the LNS and MMN groups for LBW (RR 0.92, 95% CI 0.74 to 1.14; 3 studies, 2404 participants), birth weight (MD 23.67 g, 95% CI -10.53 to 57.86; 3 studies, 2573 participants), birth length (MD 0.20 cm, 95% CI -0.02 to 0.42; 3 studies, 2567 participants), SGA (RR 0.95, 95% CI 0.84 to 1.07; 3 studies, 2393 participants), preterm delivery (RR 1.15, 95% CI 0.93 to 1.42; 3 studies, 2630 participants), head circumference z score (MD 0.10, 95% CI -0.01 to 0.21; 2 studies, 1549 participants) or neonatal death (RR 0.88, 95% CI 0.36 to 2.15; 1 study, 1175 participants).
Authors' conclusions: Findings from this review suggest that LNS supplementation has a slight, positive effect on weight at birth, length at birth, SGA and newborn stunting compared to IFA. LNS and MMN were comparable for all maternal, birth and infant outcomes. Both IFA and MMN were better at reducing maternal anaemia when compared to LNS. We did not find any trials for LNS given to pregnant women in emergency settings.Readers should interpret the beneficial findings of the review with caution since the evidence comes from a small number of trials, with one-large scale study (conducted in community settings in Bangladesh) driving most of the impact. In addition, effect sizes are too small to propose any concrete recommendation for practice.