Vitamin C supplementation in pregnancy

Area of Science:

• Obstetrics and Gynecology
• Nutritional Science
• Clinical Trials

Background:

• Pregnancy complications such as pre-eclampsia, intrauterine growth restriction, and maternal anemia may be reduced by Vitamin C supplementation.
• Further evaluation of Vitamin C's efficacy and safety during pregnancy is warranted.

Purpose of the Study:

• To assess the impact of Vitamin C supplementation, alone or with other nutrients, on pregnancy outcomes.
• To evaluate adverse events, side effects, and healthcare resource utilization associated with Vitamin C supplementation in pregnancy.

Main Methods:

• Systematic review of randomized and quasi-randomized controlled trials.
• Searches conducted in major medical databases including Cochrane Pregnancy and Childbirth Group Trials Register, MEDLINE, Current Contents, and EMBASE.
• Exclusion of trials involving multivitamins with Vitamin C or iron as the primary supplement.

Main Results:

• Five trials involving 766 women were included. No significant differences were observed for stillbirth, perinatal death, birthweight, or intrauterine growth restriction.
• Vitamin C supplementation was associated with an increased risk of preterm birth (RR 1.38, 95% CI 1.04 to 1.82).
• Heterogeneity was noted for neonatal death and pre-eclampsia; a reduced risk of pre-eclampsia was suggested by fixed-effect models but not by random-effects models.

Conclusions:

• Current data are insufficient to confirm the benefits of Vitamin C supplementation during pregnancy.
• An increased risk of preterm birth may be associated with Vitamin C supplementation in pregnancy.