(photo credit: INGIMAGE)
Women who become pregnant despite using an intrauterine device are at greater risk of delivering prematurely, having low birth-weight babies, suffering from bacterial infections or losing their fetuses, according to researchers at Ben-Gurion University of the Negev and Soroka-University Medical Center in Beersheba.
The research will be presented at the 38th annual meeting of the Society for Maternal-Fetal Medicine in Dallas, Texas, on January 29.
“We believe this is the first report tracking children born to mothers using an IUD over a long time-frame,” said Dr. Gali Pariente, a faculty member at BGU’s Division of Obstetrics and Gynecology in the Faculty of Health Sciences and a clinical instructor at Soroka. “Working with a large sample over 23 years allowed us to investigate obstetric parameters that hadn’t been examined previously in large groups.”
IUDs are the most popular form of reversible contraception worldwide. Nearly as effective as sterilization, yet not as permanent, the devices are the preferred birth control method for 23% of female contraceptive users, according to a 2015 UN report on worldwide contraceptive use.
An IUD is recognized by the uterus as a foreign body, leading it to produce an inflammatory response that impairs sperm implantation. Adding copper or progesterone to the device enhances that response and stimulates further barriers which inhibit sperm from binding with an egg. The risk of IUD failure is highest during the first year after insertion.
In the study, researchers compared the outcomes of 221,800 deliveries from 1991 through 2014. During that time, 203 women, or nearly 1% of those in the study who delivered babies, had an IUD that was removed early in the pregnancy, and 6% retained their IUD throughout gestation.
Women who conceived with an IUD were more likely to have one or more adverse outcomes including: pre-term delivery – 14.3% who removed their IUD and 14.1% who retained their IUD had pre-term deliveries vs. 6.8% without an IUD; bacterial infection, or chorioamnionitis – nearly 5% who removed their IUD and 2.7% who retained their IUD developed a bacterial infection vs. 0.6% without an IUD; low birth weight – 11.3% who removed their IUD and 12.1% who retained their IUD delivered babies under 2.6 kg. vs. 6.6% without an IUD; and perinatal mortality – 2% who removed their IUDs and 1.3% who retained their IUDs lost the fetus vs. 0.5% without an IUD.
The study, Perinatal Outcomes of Pregnancies in Women Who Conceived While Using an IUD, will be presented at the Texas conference by Pariente, Dr. Tamar Wainstock of BGU’s School of Public Health, and Prof. Eyal Sheiner, vice dean for student affairs of the Faculty of Health Sciences, who is also head of Soroka’s obstetrics department.
“Because of the elevated risks of severe, adverse, short-term perinatal complications, we recommend careful monitoring of any women who conceives while using an IUD,” advised Pariente.