Depo-Provera, an injectable contraceptive
By Donald G. McNeil Jr.
THE hormone shot — popular among African women who must use birth control in secret — is as safe as other methods, scientists reported.
For decades, many African women in need of birth control they could use in secret have relied on intramuscular hormone injections that prevent pregnancy for three months.
But in recent years, women have been terrified — and family planning officials frustrated — as studies suggested that women using injectables were far more likely to get infected with H.I.V.
On Thursday, a major new study found that women who did were not at a much greater risk than they were from other contraceptive methods, including a hormone implant or a copper intrauterine device.The World Health Organization will view the study next month as it debates whether to give back the injectable its top safety rating. Two years ago, the W.H.O. lowered its rating one notch, but said the benefits still outweighed the risks.
The hormone is known as DMPA, for intramuscular depot medroxyprogesterone acetate, and is marketed by Pfizer under the brand name Depo-Provera.
The study, which involved more than 7,800 women in four African countries and was published in The Lancet, pleased advocates for women’s health.
The results “will be a relief to both women and health care providers in southern Africa, where Depo-Provera is the most commonly used contraceptive,” said Dr. Salim S. Abdool Karim, an H.I.V. expert at the University of KwaZulu-Natal in South Africa and Columbia University, who was not involved in the trial.
Still, he cautioned, Depo-Provera appeared to pose a “marginally” higher risk of H.I.V. infection than contraceptive implants, which are silicon tubes inserted under the skin that release only small amounts of hormone at once.
The results also remove some obstacles to contraception technologies of the future, said one of the study’s authors, Dr. Timothy D. Mastro, chief science officer at FHI360, a consultancy in North Carolina.
Birth-control shots that women can safely give themselves are being developed, as are injectables that last six months. If the trial had found hormonal methods dangerous, “a whole avenue of advances would have been shut off,” Dr. Mastro said.
Depo-Provera is a mainstay of family planning across much of Africa, where H.I.V. remains rampant. In public health clinics, the shot is sometimes the only choice offered.
Three years ago, India began officially urging women to choose itover tubal ligation, which the government had long promoted.
In Africa, women often prefer Depo-Provera because many men refuse to use condoms and the injectable is easier to conceal than daily pills. Some women fear being abandoned, humiliated or even beaten if they are caught avoiding pregnancy.
“Their husbands or partners, and their families, often want them to have children,” said Dr. Sheena McCormack, an H.I.V. specialist at Britain’s Medical Research Council who has conducted trials on H.I.V. prevention methods but was not involved in the current study.
Starting more than a decade ago, some scientists warned that Depo-Provera seemed to raise a woman’s risk of getting H.I.V. by 40 percent or more. One study even concluded that the risk was doubled among women using it.
Why that happened was unknown. Tests on monkeys suggested the hormone in the shot, progestin, might thin the protective vaginal mucus or make immune cells in the vaginal tract replicate H.I.V. more quickly.
But scientists had drawn their conclusions from epidemiological studies and lab tests. The new research, known as Echo (officially, Evidence for Contraceptive Options and H.I.V. Outcomes), was designed as a randomized clinical trial, the medical gold standard.
-The New York Times