Emergency contraception works by stopping or delaying ovulation, by preventing fertilization, and by keeping a fertilized egg from attaching to the uterus, but it will not end an existing pregnancy. Emergency contraception should be taken within 72 hours of unprotected intercourse — the sooner the better — and can decrease the likelihood of conception by as much as 89%. Plan B is available at pharmacies and family planning clinics with a prescription from a health-care provider. Because there is a risk of nausea and vomiting with Plan B, some doctors may also prescribe an antinausea medicine. Progestin-only contraceptives such as Plan B may cause a slight deterioration in glucose tolerance, so women with diabetes who have taken this contraceptive should be monitored by their health-care provider.
Ortho Evra patch
The first transdermal contraceptive, the Ortho Evra patch is worn for three weeks (each individual patch lasts a week) on the lower abdomen, buttock, or upper arm, where it delivers a continuous level of progestin and estrogen through the skin. Each three-week interval is followed by a patch-free week during which a woman has her period. The Ortho Evra patch is about 99% effective if used correctly. If a patch comes off before the week is over, a new patch should be applied as soon as possible for the remainder of the week. If more than 24 hours go by before a new patch can be applied, backup birth control must be used. This method is less effective in women who weigh more than 198 pounds and it should not be used by women with diabetes who have vascular complications. The Ortho Evra patch is available by prescription and costs about $30 a month.
A novel concept in contraception, the NuvaRing is a flexible polymer ring worn in the vagina. It is approximately two inches in diameter and contains low levels of hormones. The ring is inserted by a woman on or before the fifth day of her period by pinching the sides of the ring together and gently pushing it into her vagina where it releases low levels of estrogen and progestin for 21 days. Because NuvaRing is not a barrier method, precise placement is not essential. Efficacy is compromised, however, if the ring slips out of the vagina and is not replaced within three hours, or if it is left in for more than four weeks or removed before the three weeks is up. In clinical testing, NuvaRing has shown to be 99% effective, the same as the pill. This method should not be used by women with diabetes who have kidney, eye, nerve, or vascular complications. NuvaRing is available by prescription and costs about $30 a month.
Mirena intrauterine device
Although they are very popular worldwide, intrauterine devices (IUDs) have had a bad reputation in the United States since the Dalkon Shield scare of the 1970’s. (This brand of IUD was linked to an increased risk of pelvic inflammatory disease, attributed to the wicking effect of the multifilamented string.) In spite of the negative associations caused by this episode, the risk of pelvic inflammatory disease related to IUDs is actually quite low, and they provide a highly effective, easily reversible birth control option for women who have had one or more children and who are in a monogamous relationship. The latest IUD to come on the market, Mirena, consists of a small, flexible, T-shaped plastic frame that releases small amounts of levonorgestrel, a type of progestin. This device does not contain estrogen, so it does not cause estrogen-related side effects and complications such as headaches and breast tenderness. Progestin-related side effects are kept to a minimum as well because all of the hormone released, about one-seventh of the amount released by birth control pills, goes directly to the uterine lining rather than through the bloodstream. There may be cramping and dizziness at the time of insertion, so it’s not a bad idea to take a painkiller such as ibuprofen prior to the office visit. There may be spotting or light bleeding between periods for the first three to six months, after which periods usually become lighter — in contrast to most IUDs, which tend to cause heavier periods. Mirena, which is over 99% effective, can stay in the uterus for up to five years, at which time a new Mirena can be inserted. The device costs about $475, plus the cost of insertion.