Incidence of hyperprolactinemia during oral contraceptive therapy.

A study at the New York Medical College Metropolitan Hospital Center involved 123 women who used oral contraceptives anywhere from 6 to 144 months. The women were divided into 3 groups according to estrogen dosages: 1) group A took estrogen compounds containing 80 or 100 ug; 2) group B took estrogen compounds of 50 ug; and 3) group C took estrogen compounds containing 20 or 30 ug. hPRL (human prolactin) levels were determined by radioimmunoassay with a normal level of hPRL being 2.2 or 20.0 ng/ml. Results were categorized as mild (20-40 ng/ml) moderate (41-60 ng/ml) greater than 60 ng/ml). 69.1% exhibited normal hPRL levels 1.1% exhibited mild levels 5.7% exhibited moderate levels and 4.1% exhibited marked levels. Neither dose nor duration of oral contraceptive therapy appeared to effect presence or degree of hyperprolactinemia. 42% of the women using oral contraceptives for less than 6 months exhibited increased hPRL levels while only 12% of the women using the pill for over 12 months were affected.