The World Health Organization (WHO) currently recommends daily iron and folic acid supplementation during pregnancy to prevent maternal anaemia, preterm birth, and small for gestational age.3
Anaemia, particularly severe anaemia, is also associated with an increased risk of multiple perinatal complications and maternal mortality.4
A study by Yakoob and Bhutta found that daily iron supplementation alone or in combination with folic acid resulted in a 73% reduction in the incidence of anaemia at term.4
Furthermore, an analysis by Haider et al found that supplementation with iron and folic acid supplementation resulted in fewer low birthweight and small‐for‐gestational‐age babies.5
The 2022 European Society of Human Reproduction and Embryology guideline recommends that folic acid should be routinely started preconceptionally to prevent neural tube defects(NTDs).6
What about other micronutrients?
Currently, the WHO does not recommend the routine use of multiple‐micronutrient (MMN)supplementation.3 But according to Haider et al, MMN deficiencies often coexist in women of reproductive age – especially in low‐ and middle‐income countries (LMICs).5
Deficiencies in vitamins A, B-complex, D, E, zinc, calcium, copper, magnesium, selenium, omega 3, and iodine during pregnancies have been reported in LMICs. Deficiencies are due to the increased demands on the mother’s body, leading to potentially adverse effects on the mother and developing foetus.5,7
Smith et al found that antenatal MMN supplements significantly reduced the risk of neonatal mortality by 15% among females with a similar magnitude of reduction for early neonatal, six months, and infant mortality (especially girls).7
MMN supplements provided significantly greater six-month mortality reduction among anaemic pregnant women as compared with non-anaemic pregnant women.7
Among all live births, MMN supplements significantly reduced the risk of extremely low birthweight, low birthweight, early preterm, preterm, and small-for-gestational-age births in anaemic pregnant women and among pregnant women and those with a body mass index <18.5 kg/m2.7
Women initiating MMN supplements before 20 weeks gestation had greater reductions in the risk of preterm birth. However, MMN supplements provided greater reductions in the risk of small-for-gestational-age birth in women initiating supplementation after 20 weeks.7
The authors stressed that maternal adherence to the intervention also modified the effect of multiple micronutrient supplements on infant mortality, with survival benefits for infants born to women with higher than 95% adherence to the supplements.7
Benefits of micronutrient supplementation in pregnancy
Vitamin A: important for both the expectant mother and the foetus. It is essential for the maintenance of maternal night vision and foetal ocular health as well as the development of other organs, the foetal skeleton, and maintenance of the foetal immune system.8
Vitamin-B complex: maternal vitamin B-12 deficiency is associated with increased risk of pregnancy complications (eg miscarriage, small-for-gestational age, low birth weight, intrauterine growth restriction, and NTDs. Infants born to vitamin B-12-deficient women are at increased risk of developmental abnormalities, growth failure, and anaemia. Insufficiency canalso impair infant growth, psychomotor function, and brain development, which may be irreversible.9
Vitamin D: deficiency during pregnancy has been associated with an increased risk of pre-eclampsia, which is associated with an increase in maternal and perinatal morbidity and mortality.10
Vitamin E: supplementation may help reduce the risk of pregnancy complications involving oxidative stress, including pre-eclampsia.11
Zinc: supplementation may reduce the risk of pre-term births (14%).12
Calcium: supplementation during pregnancy leads to a reduction of 59% in risk of pre-eclampsia, 45% in risk of development of gestational hypertension and 12% in risk of preterm birth in developing countries. Calcium supplementation is necessary for all women during pregnancy in developing countries, state the authors of this study.13
Copper: low serum copper levels in early pregnancy are associated with a higher risk of pregnancy-induced hypertension.14
Magnesium: supplementation during pregnancy may be able to reduce foetal growth restriction and pre‐eclampsia and increase birthweight.15
Selenium: deficiencies may lead to gestational complications, miscarriages, and damage to thenervous and immune systems of the foetus. A low concentration of selenium in blood serum in the early stage of pregnancy has been shown to be a predictor of low birth weight. Supplementation during pregnancy may also reduce postpartum thyroid dysfunction.16,17
Iodine: deficiency is a leading cause of maternal hypothyroidism. Maternal iodine deficiency in pregnancy has been associated with increased risks of obstetric complications such as miscarriage, prematurity, stillbirth, and low birth weight. Maternal iodine deficiency has also been associated with impaired neurodevelopment, including cretinism and lower IQ.18
Omega 3: Adequate consumption of omega-3 fatty acids is vitally important during pregnancy as they are critical building blocks of foetal brain and retina. Omega-3 fatty acids may also play a role in determining the length of gestation and in preventing perinatal depression.19
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