Fatty acids in human milk and steroidal contraceptives in Hungary and Thailand

Abstract

A controlled double-blind clinical trial was carried out in Hungary and Thailand to assess the effects of contraceptive hormones on human breast milk. Subjects were randomly assigned to 1 of 4 treatments: 1) control group--no treatment 2) 75 mcg d-1 norgestrel 3) 150 mcg levonorgestrel and 30 mcg ethinyl estradiol and 4) injectable depot-medroxyprogesterone acetate (DMPA). Milk was collected from study subjects at 3 6 9 12 16 20 and 24 weeks postpartum and fatty acid analysis was performed. At the study center in Hungary no differences were found in the proportion of lipid in the milk of subjects compared with controls. Among study subjects from Thailand however a reduction in the proportion of total milk lipid was found for the DMPA and progestin-only treatment groups. The percentage proportions of the shorter chain fatty acids were increased during the combined hormonal treatment in both centers. There was no evidence of an alteration of the ratio of linoleic acid to arachidonic acid in the milk before or after any of the treatments in Thailand. It is hypothesized that the impact of steroidal preparations on milk lipids in Thailand but not in Hungary reflects differences in nutritional backgrounds in the countries. Fat is the source of 10-15% of the mothers dietary energy in Thailand compared with 38-42% in Hungary. These findings suggest that the effect of contraceptive hormones on breast milk may be greater in developing countries where the intake of dietary fat is generally lower.