Association of arsenic with adverse pregnancy outcomes/infant mortality: a systematic review and meta-analysis

Abstract

Background: Exposure to arsenic is one of the major global health problems, affecting > 300 million people worldwide, but arsenic's effects on human reproduction are uncertain.

Objectives: We conducted a systematic review and meta-analysis to examine the association between arsenic and adverse pregnancy outcomes/infant mortality.

Methods: We searched PubMed and Ovid MEDLINE (from 1946 through July 2013) and EMBASE (from 1988 through July 2013) databases and the reference lists of reviews and relevant articles. Studies satisfying our a priori eligibility criteria were evaluated independently by two authors.

Results: Our systematic search yielded 888 articles; of these, 23 were included in the systematic review. Sixteen provided sufficient data for our quantitative analysis. Arsenic in groundwater (≥ 50 μg/L) was associated with increased risk of spontaneous abortion (6 studies: OR = 1.98; 95% CI: 1.27, 3.10), stillbirth (9 studies: OR = 1.77; 95% CI: 1.32, 2.36), moderate risk of neonatal mortality (5 studies: OR = 1.51; 95% CI: 1.28, 1.78), and infant mortality (7 studies: OR = 1.35; 95% CI: 1.12, 1.62). Exposure to environmental arsenic was associated with a significant reduction in birth weight (4 studies: β = -53.2 g; 95% CI: -94.9, -11.4). There was paucity of evidence for low-to-moderate arsenic dose.

Conclusions: Arsenic is associated with adverse pregnancy outcomes and infant mortality. The interpretation of the causal association is hampered by methodological challenges and limited number of studies on dose response. Exposure to arsenic continues to be a major global health issue, and we therefore advocate for high-quality prospective studies that include individual-level data to quantify the impact of arsenic on adverse pregnancy outcomes/infant mortality.

Figure 1

Study selection flow diagram.

Figure 2

Forest plot for the relation between arsenic exposure and the risk of spontaneous abortion, assessed by (A) high arsenic dose and (B) low to moderate arsenic dose.

Figure 3

Plots of dose–response relations for arsenic and (A) spontaneous abortion, (B) stillbirth, (C) neonatal mortality, and (D) infant mortality in the general population.

Figure 4

Forest plot for the relation between arsenic exposure and the risk of stillbirth, assessed by (A) high arsenic dose and (B) low to moderate arsenic dose.

Figure 5

Forest plot for the relation between arsenic exposure and (A) preterm delivery, (B) birth weight, (C) neonatal mortality, and (D) infant mortality.