Minipill: The progestin-only pill has many of the advantages of the Norplant and Depo-Provera injection. It is used very infrequently. It is known to be less effective than combination oral contraceptives, Norplant, and Depo-Provera. However, it is a viable alternative in women who breast-feed and are unable to use estrogen. It has the advantage of being stopped easily. Its effectiveness rate is intensified if it causes anovulation, menstrual irregularities, and amenorrhea.
a. Efficacy: The failure rate of the Minipill in the first year of typical use is 1.1% to 13.2%. If used perfectly, only 5 in 1000 women become pregnant in the first year. It is nearly 100% effective in lactating women and does not affect milk production.
(1) Women for whom estrogen is contraindicated
(2) Decreases blood loss during menses, therefore decreasing anemia, dysmenorrhea, and mittelschmerz
(3) Decrease in endometrial and ovarian cancer and PID
(4) Immediate reversibility
(5) Indicated for women who develop headache and hypertension on combination oral contraceptives
c. Side effects.
(1) There are changes in menstrual cycles (more spotting and irregularity). These changes are sometimes unacceptable to women.
(2) Interaction with anticonvulsants makes the Minipill less effective.
(3) The risk of pregnancy is greater unless the cycles are disturbed.
(4) The Minipill must be taken with exact regularity.
(5) The Minipill is less available.
(6) Practitioners have less experience with the Minipill.
(7) Ovarian cysts (functional) are increased with use of the Minipill.
(8) Ectopic pregnancy is more common with failures.
4. Delivery systems: Delivery systems for progestin-only contraceptives and combined pills are outlined in Table (Delivery Systems for Progestin-Only Contraceptives and Combined Pills.)