Long-term effects of iron supplements during pregnancy – adapted from the American Journal of Obstetrics and Gynecology, June 1995

Long-term effects of iron supplements during pregnancy – adapted from the American Journal of Obstetrics and Gynecology, June 1995 – Tips from Other Journals

In a study of routine and selective iron prophylaxis during pregnancy, Hemminki and Merilainen concluded that routine prophylaxis is not crucial for maternal or infant health during pregnancy or through the first eight weeks after delivery The researchers extended the original trial to investigate subsequent maternal and infant health and subsequent reproductive outcome.

In the original trial, perinatal mortality was found to be somewhat higher in the group receiving routine iron prophylaxis than in the group selectively given prophylaxis. In the extended study, patients were followed over a seven-year period; only 2.1 percent of the original study population could not be traced for data collection.

The long-term follow-up revealed one new infant death in the group that received selective iron prophylaxis; this death was the result of complications of an operation to correct a congenital heart defect. The incidence of maternal death during follow-up was lower than expected among the total population of matched subjects. Thirty percent of the infants were traced in the hospital inpatient register during the follow-up period, and no difference was found between the two groups with regard to the number of hospital visits. However, children in the routine prophylaxis group had significantly more seizures than children in the selective treatment group.

The number of mothers who were admitted to the hospital did not differ between the two groups. Also, diagnoses for which the women were admitted did not differ significantly. Almost 50 percent of the women had at least one subsequent birth during the seven-year follow-up period. The proportion of women giving birth, the timing of the births, the number of hospital admissions during pregnancy and the length of hospitalization during the birth did not differ significantly between the two groups. No difference was found in the proportion of women who had a miscarriage or had an elective termination of pregnancy during the follow-up period. The outcome of the subsequent birth in terms of perinatal mortality, proportions of preterm and low-birth-weight infants and mean gestational age at delivery also did not differ significantly between the two groups.

The authors conclude that findings of this long-term follow-up study do not support the use of routine over selective iron prophylaxis during pregnancy. Overall findings showed that both infants and mothers of the two groups fared equally well. The only significant finding was that more infants in the routine prophylaxis group were hospitalized because of seizures. The authors suggest that fetal exposure to iron during pregnancy may increase the risk of seizures in the first year of life. This finding warrants further study (American Journal of Obstetrics and Gynecology, July 1995, vol. 173, p. 205.

COPYRIGHT 1995 American Academy of Family Physicians

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