Vitamin D deficiency and anemia in pregnant women: a systematic review and meta-analysis.

CONTEXT: Epidemiological studies suggest an association between vitamin D deficiency and anemia. Evidence of this relationship in pregnant women, however, is scarce. OBJECTIVE: The aim of this systematic review was to investigate the association between vitamin D deficiency and gestational anemia through observational studies. DATA SOURCES: The PubMed, Scopus, Web of Science, ScienceDirect, Embase, and Virtual Health Library databases were searched from inception to April 2021. STUDY SELECTION: Original articles reporting observational studies that investigated the association between vitamin D deficiency and gestational anemia were included. Articles that did not have an abstract, as well as reviews articles, experimental studies, and editorials, were excluded. Two reviewers independently performed study selection, data extraction, and assessment of study quality. Disagreements between the reviewers were resolved by a third reviewer. DATA EXTRACTION: Study quality was assessed by 2 scales. Data were extracted from eligible studies and arranged in a 2 × 2 table. Odds ratios with 95% confidence intervals for the risk of the outcome were estimated using a fixed-effect model. RESULTS: In total, 985 studies were retrieved, of which 17 were included in the systematic review: 11 cohort studies, 3 case-control studies, and 3 cross-sectional studies. For the meta-analysis, 8 studies with a total of 6530 women were included. There was a 61% increase in the odds of anemia in pregnant women with vitamin D deficiency (OR = 1.61; 95%CI, 1.41-1.83; I2 = 48%). CONCLUSIONS: Vitamin D deficiency may be a risk factor for anemia in pregnant women. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42020182697.

Effect of Acetaminophen use during pregnancy on adverse pregnancy outcomes: a systematic review and meta-analysis.

INTRODUCTION: A high number of women are exposed to acetaminophen during pregnancy worldwide. This drug safety during pregnancy regarding preterm birth, birth weight, and fetal development has not been well described. This study investigated the effect of acetaminophen use during pregnancy on selected adverse pregnancy outcomes. AREAS COVERED: Databases were searched to identify studies reporting the effects of acetaminophen use during pregnancy on preterm birth, low birth weight, and small for gestational age. The studies' quality was assessed by the Newcastle-Ottawa Scale and the Methodological Index for Non-Randomized Studies. Risk ratios with 95% confidence intervals were estimated using a fixed or random-effects model. Six studies were included for final review, four cohort and two case-control studies. We found no increased risk of preterm birth (RR 0.97; 95% CI 0.59-1.58), and decreased risks of low birth weight (RR 0.65; 95% CI 0.59-0.72) and small for gestational age (RR 0.69; 95% CI 0.50-0.97). Acetaminophen exposure during the third trimester revealed non-significantly in the outcomes. EXPERT OPINION: Exposure to acetaminophen during pregnancy appears to not increase the risk of the outcomes analyzed. However, there is a lack of information regarding the exposure dose and frequency of acetaminophen use.