Dr Maclawrence Famuyiwa
Public Health/Infectious Disease Specialist
The nutritional status of a woman, before getting pregnant, is very vital since it has a great impart on the very first developmental stages of the pregnancy, hence, can significantly affect pregnancy outcomes.
Undernourishment in pregnancy together with specific micro-nutrient deficiencies can cause miscarriage, congenital abnormalities, impaired placental development and may result in intrauterine growth retardation (IUGR), pre-eclampsia, and preterm birth.
An undernourished pregnant woman is particularly vulnerable to infections. This is because pregnancy is a time of high nutrients requirements, especially, during the last three months of pregnancy, when the foetus grows fastest. It is also the time when immunity of the woman significantly wanes, to accommodate the presence of the growing foetus. This immune system impairment thus makes pregnant women more susceptible to many pathogens such as malaria, tuberculosis, intestinal parasites and gastrointestinal pathogens.
Adolescent pregnant women are particularly, more vulnerable to infections and undernutrition. They have significantly higher levels of deaths of their newborns and infants. Adolescence is the period in which a significant proportion of growth occurs. It is the period in which up to 50 per cent of body weight and 15 per cent of adult height are gained, the more reason why they need higher nutrient intakes. Failure to meet the nutritional needs of adolescent will lead to cessation of their growth, making them to end up with shorter adult stature, increased risk of obstetric problems and perpetuation of the inter-generational cycle of malnutrition.
The nutritional needs of a pregnant woman increase as the pregnancy progresses and the foetus grows and develops. A failure to meet this increase nutritional need will lead to the utilisation of the maternal stores and tissues causing the deterioration of the nutritional status of the mother. This is worsens if successive pregnancies are insufficiently spaced, to allow for replenishment of the stores to restore the normal nutritional status of the mother.
Malnutrition in pregnancy can also cause small for gestation age infants, diminished nutrients stores and delayed development of tissues and organs like that of the digestive system of the newborn. This is because the developing foetus requires nutrients for growth and development of tissues such as the immune system. Maternal obesity, on the other hand, has been associated with maternal morbidity and mortality, preterm birth and increased infant infections and mortality.
There are two categories of nutrients: macro-nutrients and micro-nutrients. Macro-nutrients are needed in large amounts and provide the body with energy, on the other hand, micro-nutrients are needed in small amounts, hence the prefixes of ‘Macro’ and ‘Micro’. Macro-nutrients are in the forms of fats, carbohydrates and proteins. Micro-nutrients consist of vitamins and minerals.
Macro-nutrients are of importance during the last three months of pregnancy and lactation period. This is the time that the nutritional needs of the foetus or newborn are substantial and it is a significant portion of the maternal intake. Micro-nutrients, however, are essential at all stages of pregnancy, so, pregnancy can cause or accentuate their deficiencies. However, it should be stated that malnutrition is often a combination of a lack of both macro- and micro-nutrients, and it produces a vast variation of potential effects on pregnancy outcomes.
Though the significance of micro-nutrients in all stages of pregnancy was alluded to above, but some of them are not recommended as part of routine care in pregnancy. For example, vitamin A and zinc play important parts in immune system development, however, vitamin A in high doses can cause birth defects. It is only useful in low doses, during pregnancy, to treat night blindness. Meanwhile, zinc supplementation during pregnancy is known to reduce the risk of preterm birth and to promote growth.
Also, even though, iron supplementation, usually combined with folate, is globally used to combat anaemia and to prevent subsequent folate deficiency during pregnancy, but it may lead to an increase in malaria prevalence, hence one of the reasons why anti-malaria prophylaxis is needed in routine antenatal care. However, daily use of iron by pregnant women has been proven to improve birth weight.
It is, therefore, sacrosanct that pregnant women should eat balanced diet. This is even of more significance in adolescent pregnant women. There are a range of cost effective interventions to treat inadequate nutrition in pregnant women. For example, for those relating to immune function, balanced food supplementation, which is the provision of additional food to ensure balanced diet; multiple micro-nutrient supplementation and iron/folate supplementation are some of the possible interventions. This should be done alongside infectious disease control because of the vulnerability of pregnant women to infection and the fact that the control of infectious disease can on its own contribute to improved nutritional status in pregnancy.