Zinc Deficiency and Its Consequences During Pregnancy

Abstract

Zinc is an important microelement that promotes immunity, proper development and growth of the nervous system and resistance to infection. It is a constituent of more than 200 enzymes involved in digestion, metabolism, synthesis of RNA and DNA, reproduction and is also essential for healthy pregnancy outcomes. An estimated 17.3% of global population is at risk for zinc deficiency due to inadequate dietary supply and bioavailability. Inadequate intake of zinc during pregnancy has been related to adverse pregnancy outcomes including abortion, foetal neural tube defects, membrane rupture, preterm delivery, prolonged labour and stillbirth and risk of maternal and infant mortality. Other risk factors of zinc deficiency are diarrheal disease, malabsorption syndromes, parasitosis, hot and humid climate, rapid multiplicative cell growth (pregnancy, infancy, and adolescence), lactation and genetic disease. Zinc deficiency is primarily related to the poor zinc status of the diet. Animal protein-based diet is a rich source of zinc, whereas vegetable and cereal-based diet is not only poor in zinc content but also interferes with its absorption due to high content of phytates. Zinc supplementation during pregnancy and lactation plays a role in improving both maternal and foetal health. Zinc supplementation reduces the frequency of preterm birth by 14%, decreases respiratory infections and childhood diarrhoea, lowers all-cause mortality and increases growth and weight gain among infants and young children. While there are no separate programmes for zinc supplementation in India, zinc tablets are provided along with oral rehydration solution (ORS) for treatment of diarrhoea as per WHO guidelines. More research is required to assess the benefits of the large-scale zinc intervention programmes during pregnancy. This chapter reviews the importance of zinc in pregnancy and its effect on foetal and infant growth.