Long-term follow-up of children breast-fed by mothers using oral contraceptives.

In a long-term follow-up study 48 breast-fed children, whose mothers had used oral contraceptives containing 50 micrograms of ethinylestradiol while lactating, were compared to a matched control group whose mothers had not used any hormonal contraceptives during lactation. In spite of a very large number of data collected from several different sources of information, no effect could be demonstrated of the ingested steroid, neither upon the panorama of diseases nor upon intellectual or psychological behaviour of the infants and children up to 8 years of age. The mothers who used oral contraceptives lactated a significantly shorter period of time than the controls, but no differences were found in weight gain and height increase in the children between cases and controls.