Zinc and pregnancy outcome.

Area of Science:

• Human Pregnancy
• Maternal Nutrition
• Mineral Metabolism

Background:

• Pregnancy significantly increases maternal zinc requirements, estimated at 2.6 mg absorbed zinc per day during the latter half.
• Physiological adaptations, including enhanced absorption and reduced loss, help meet these heightened zinc demands.
• Circulating zinc levels naturally decline throughout gestation, necessitating adjusted reference ranges for pregnant women.

Purpose of the Study:

• To review zinc utilization and requirements during human pregnancy.
• To examine the association between maternal zinc status and pregnancy outcomes.
• To evaluate the efficacy of zinc supplementation in improving pregnancy outcomes.

Main Methods:

• Literature review of studies on zinc metabolism and requirements in pregnancy.
• Analysis of the relationship between maternal serum zinc concentrations and pregnancy complications.
• Examination of clinical trial data on zinc supplementation during pregnancy.

Main Results:

• Maternal zinc absorption increases, endogenous losses decrease, and tissue zinc is redistributed to support fetal development.
• Low maternal serum zinc is correlated with pregnancy-induced hypertension, abnormal labor, and congenital anomalies.
• Zinc supplementation (15-45 mg/d) has shown limited benefits, with only a potential reduction in dysfunctional labor.

Conclusions:

• Pregnancy involves complex maternal zinc adaptations to meet fetal demands.
• Low maternal zinc status is a risk factor for adverse pregnancy outcomes.
• The overall impact of zinc supplementation on pregnancy outcomes requires further investigation, as current evidence is inconclusive.