Minipill: miniprotection from ectopic pregnancy.

Abstract

The progestogen-only minipill appears to offer only minimal protection against ectopic pregnancy according to 3 reports. In 1 report, 2 ectopic pregnancies occurred among 135 women taking .35 mg norethisterone for a total of 1024 woman-months, and 2 other ectopic pregnancies occurred in a group of women who completed 650 woman-months, yielding and approximate rate of 2/100 woman per year of use. In another report, 3 ectopic pregnancies were found among a group of 535 women using minipills for 4594 woman-months. Of these, 1 woman had used .5 mg chlormadinone acetate daily, another .35 mg norethisterone, and the third, .5 mg megestrol acetate. These failure rates ranged from .6 to 1.2 ectopic pregnancies per 100 woman-years of use. There were 35 pregnancies among these women, 8.6% of which were ectopic. In another report, there were 3 ectopic pregnancies among 73 pregnancies. This proportion, 4.1%, was similar to that reported for pregnancies among IUD users. It was noted that side effects of progestogen-only contraception, e.g., spotting and breakthrough bleeding, lengthened cycle, and amenorrhea, are also symptoms of ectopic pregnancy. Physicians should consider ectopic pregnancy when patients are taking minipill contraceptives.