One pregnancy
The trial included women aged 18-35 years who requested emergency contraception after unprotected sexual intercourse within the previous 5 days. Other inclusion criteria were that participants had a desire to initiate use of an IUD; a desire to prevent pregnancy for at least 1 year; a negative result on urine pregnancy testing; a history of regular menstrual cycles; and a known date of the last menstrual period. The investigators did not exclude individuals who had unprotected sexual intercourse more than 5 days before IUD placement.
Participants were unaware of their assigned intervention. The nurse practitioners and certified nurse midwives who performed the IUD insertions were aware of the IUD type.
The primary outcome was pregnancy, as determined by a positive result on urine pregnancy testing 1 month after IUD insertion or by a review of survey and health record data.
One pregnancy “occurred in a participant who reported a single episode of unprotected sexual intercourse 48 hours before IUD placement,” the study authors wrote. “Pregnancy dating by an ultrasound examination at 10 weeks was consistent with conception occurring as a result of an emergency contraception failure. The pregnancy ended in a spontaneous abortion at 10 weeks with the IUD still in place.”
“We hope that providers can begin to deliver this method to everyone who wants and needs it and that people considering both emergency contraception and an ongoing method of birth control know that they now have the option of a hormonal IUD in addition to the nonhormonal, copper IUD,” Dr. Turok said in a news release from Planned Parenthood.
The study used a hormonal IUD manufactured by Liletta; Mirena also manufactures a levonorgestrel 52-mg IUD. The results of the study would apply to Mirena’s product too, according to Planned Parenthood.
“There are various IUDs on the market that are at lower doses, and so those IUDs may not demonstrate similar results,” Dr. Aguilar said.
The research was supported by the National Institutes of Health and the University of Utah. Dr. Turok is the director of surgical services for Planned Parenthood Association of Utah; the trial was conducted at PPAU centers, but Dr. Turok does not work at the sites where the study was conducted. Dr. Turok has consulted for Sebela Pharmaceuticals as the principal investigator for two phase 3 studies that assessed novel IUDs. Dr. Turok and one coauthor received grant support from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Dr. Fok and Dr. Aguilar disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.