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Injectable contraception: what should the longest interval be for reinjections?
Markus J Steiner1, Cynthia Kwok, John Stanback
1Family Health International, Research Triangle Park, NC 27709, USA. msteiner@fhi.org
Contraception
|May 15, 2008
Summary
Extending the grace period for depot-medroxyprogesterone acetate (DMPA) injections to 4 weeks, from the current 2 weeks, does not increase pregnancy risk. This change could improve contraceptive continuation rates for women using DMPA.
Area of Science:
- Reproductive Health
- Contraception
- Public Health
Background:
- Progestin-only injectable contraceptives, like DMPA, are increasingly popular.
- Uncertainty exists regarding pregnancy risk for women who are late for DMPA reinjection.
- The World Health Organization (WHO) currently recommends a 2-week grace period for DMPA reinjection.
Purpose of the Study:
- To evaluate the pregnancy risk associated with extending the DMPA reinjection grace period.
- To determine if a 4-week grace period is safe and effective for DMPA users.
- To inform guidelines on DMPA injection timing and contraceptive continuation.
Main Methods:
- Prospective cohort study conducted in Uganda, Zimbabwe, and Thailand.
- Followed users of depot-medroxyprogesterone acetate (DMPA) for up to 24 months.
- Pregnancy testing at each reinjection to analyze risk among late acceptors.
Main Results:
- Analysis included 2290 participants and 13,608 DMPA intervals.
- Pregnancy risk per 100 women-years was low and similar for on-time (0.6%), 2-week grace (0.0%), and 4-week grace (0.4%) injections.
- Confidence intervals indicate minimal to no increased risk with the extended grace period.
Conclusions:
- Extending the DMPA reinjection grace period from 2 to 4 weeks does not elevate pregnancy risk.
- A longer grace period may enhance contraceptive continuation rates.
- Findings support potential adjustments to WHO guidelines for DMPA reinjection.
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