There is widespread support for use of DMPA during lactation when the DMPA is initiated at or after 6 weeks postpartum. There is good evidence that neither infant growth nor lactation is impaired by DMPA or progestin-only oral contraceptives (240). There is continued controversy as to how early DMPA should be given after delivery. Because lactation occurs in response to falling maternal estrogen and progesterone levels after birth, administration of DMPA in the first few days theoretically might interfere with the initiation of lactation. There is concern about the possible neonatal effects of the progestin, but investigators were unable to demonstrate the presence of DMPA or its metabolites in the urine of infants whose mothers received DMPA or any other suppression of reproductive hormones (240). In the United States, DMPA is commonly started at the time of hospital discharge, 48 to 72 hours after delivery. There is urgent need for controlled trials of immediate DMPA compared to other contraceptive options to determine whether this practice has an adverse effect on the initiation of lactation. The “U.S. Medical Eligibility Criteria for Contraceptive Use 2010” considers DMPA use prior to 1 month postpartum as category 2: the benefit is thought to exceed the theoretical risk (7).
Use of DMPA is not associated with cervical cancer (241). Neither is it associated with ovarian cancer (242). Risk of endometrial cancer is substantially reduced by past use of DMPA (243). A large study found no increase in breast cancer risk among DMPA users (244).
DMPA has many of the noncontraceptive benefits of combination oral contraceptives (245). Decreases in anemia, PID, ectopic pregnancy, and endometrial cancer are reported. DMPA is reported to benefit women with sickle cell disease.
Subcutaneous DMPA Depo-subQ Provera 104, a lower-dose DMPA preparation for subcutaneous administration, received FDA approval in 2005. The total dose is 30% less than that of the older DMPA intramuscular preparation. Because the dose is administered subcutaneously, blood levels are adequate to completely suppress ovulation for more than 13 weeks in all subjects tested, with a mean time of 30 weeks for return to ovulatory function (246). Contraception efficacy is superb, with no pregnancies in a total of 16,023 woman-cycles in the phase III studies done in the United States (247). Blood levels were lower in very obese women but still sufficient to completely suppress ovulation. The weight gain reported with the 150 mg DMPA remains a problem with the lower dose DMPA. Mean weight gain was 1.59 kg in the first year of use. Loss of bone density was observed with this dosage of DMPA, as with the larger intramuscular dose.
Once-a-Month Injectable A once-a-month injectable contraception containing only 25 mg of DMPA in combination with 5 mg of the long-acting estrogen estradiol cypionate was brieﬂy available in the United States, but was withdrawn by the manufacturer because of a packaging problem (248). Originally developed by the World Health Organization, it is described as CycloFem or CycloProvera in the literature and was marketed in the United States as Lunelle (249). Given once a month, this combination produces excellent contraceptive effects. Monthly withdrawal bleeding is similar to a normal menses, leading to high continuation rates despite the need for a monthly injection. Monthly injectable combinations continue to be widely used outside the United States.