Pregnancy risk may be higher with newer method of female sterilization

(Medical Xpress)—Women who used a new method of sterilization called hysteroscopic sterilization had a 10 times greater risk of pregnancy after one year than those who used the older laparoscopic sterilization method. This new finding by Yale School of Medicine researchers is published in the April 21 issue of the journal Contraception.

"This study provides essential information for women and their doctors discussing permanent sterilization," said lead author Dr. Aileen Gariepy, assistant professor in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine. "Women choose sterilization to specifically prevent any future pregnancies. If one sterilization method has a much higher risk of pregnancy, women and their doctors need to know that as they consider the overall risks and benefits of the procedure."

Each year, 345,000 women in the United States undergo sterilization procedures and a total of 10.3 million U.S. women now rely on female sterilization for pregnancy prevention.

Since hysteroscopic sterilizations was introduced in 2001, over 650,000 have been performed worldwide. The procedure involves placing coils inside the fallopian tubes, waiting for three months while using another birth control method, then injecting a special dye into the uterus, which is x-rayed to test if the tubes are blocked. The newer procedure may be performed in a doctor's office, without general anesthesia, and does not involve an abdominal incision.

Gariepy said there have been no prior studies comparing the effectiveness of hysteroscopic vs. laparoscopic sterilization. "This has limited providers and patients' ability to make informed decisions," she said.

Hysteroscopic sterilization is a multi-step process, and unlike laparoscopic sterilization, is not immediately effective. Previously published studies of the newer method primarily reported the outcomes only in women with successful completion of all of the steps.

This new study by Gariepy and colleagues compares hysteroscopic sterilization to laparoscopic sterilization and uses data currently available in the published literature to model what would happen to a hypothetical group of 100,000 women attempting a sterilization procedure, including those who do not successfully have the procedure. The computer model, referred to as decision analysis, takes into account all possible outcomes for each step of the process.

Gariepy and colleagues found that pregnancy rates one year after hysteroscopic sterilization are 57 per 1,000 women compared to about 3-7 per 1,000 women for laparoscopic sterilization. The total pregnancy rate over 10 years reached 96 per 1,000 women for hysteroscopic sterilization compared to only 24-30 per 1,000 women with a laparoscopic procedure.

"Unintended pregnancy resulting from sterilization failure can have serious consequences for both women's quality of life and maternal and neonatal health outcomes, and should be considered a significant adverse event," said Gariepy.