Abstract
Purpose. To compare the nutritional status of infertile women with non‐pregnant fertile age‐matched controls and to assess the periconceptional intake of nutritional supplements in pregnancy with an estimation of total micronutrient (diet and supplementary) intake.
Design. An assessment of the nutritional status of infertile women and fertile, age‐matched non‐pregnant controls and a survey of the periconceptional intake of folic acid and other nutritional supplements.
Materials and methods. Group 1: a 7‐day weighed diet diary and blood tests for magnesium, mineral and pyridoxine status were used to assess the nutritional status of six infertile women and 12 non‐pregnant, healthy, age‐matched controls. Group 2: the periconceptional dietary intake of folic acid and other nutritional supplements was estimated in 87 pregnant women attending midwife clinics, 36 women attending an assisted conception clinic and 7 women attending a self help group for lesbian pregnancy.
Results. In the group of six infertile subjects and 12 fertile controls, there was a non‐significant trend for micronutrient intake in the controls to be higher than for the infertile subjects. Comparisons with the UK reference nutrient intake confirmed suboptimal nutrition in all subjects and some controls. Twenty‐five per cent of controls and 33% of infertile subjects had subnormal serum selenium consistent with reduced antioxidant defence. There was also a non‐significant trend for non‐caeruloplasmin copper and cadmium to be higher in the infertile subjects. The combined mean dietary intake for all subjects and controls was similar to the values from the National Diet and Nutrition Survey. Therefore, an approximate value for the total intake of nutrients (diet and supplementation) of the 130 women in the larger survey was calculated using the mean dietary intake of the smaller group as an estimate of the dietary component. This analysis suggested suboptimal total intake for >50% of the subjects for selenium, zinc, magnesium and iodine and borderline total intake for >50% of subjects for vitamins B12, C and E, betacarotene, iron, folate + folic acid and essential fatty acids.
Conclusions. Current levels of supplementation with folic acid and other nutrients are failing to compensate for poor mean dietary intake of these nutrients at the time of conception. These nutritional deficiencies are probably important contributory factors in infertility, spontaneous abortion, pregnancy complications and post‐partum health problems in the mother and infant (including congenital malformations and postnatal depression).