IUD use associated with decreased risk of preeclampsia

1. Women who used an intrauterine device (IUD) were less likely to develop preeclampsia in subsequent pregnancies.

2. The protective effect of IUD use was observed in nulliparous women only.

Evidence Rating Level: 3 (Average)       

Study Rundown: Intrauterine devices (IUDs) are considered one of the most effective contraceptive methods, as they are long-acting, reversible and have minimal side effects. Three types of IUDs have been approved for use in the U.S. and include the copper IUD and 2 levonorgestrel-releasing IUDs. While more effective than many other contraceptive alternatives, the efficacy of IUDs is still not 100%. The risk of pregnancy is greatest within the first year, and women who become pregnant while an IUD is in place are at greater risk for complications such as ectopic pregnancy, miscarriage, septic abortion, and preterm delivery. While studies on pregnancies that occur while an IUD is in place have been performed, little is known about whether use of IUDs influence pregnancies that occur after IUD removal. In the present work, authors characterized the effect of prior IUD use on future preeclampsia risk and found that IUD use was associated with decreased odds of developing preeclampsia among nulliparous women.

Strengths of the study included the use of prospective data collection from a large population-based database. Limitations included case-control design, which limited inferences about causality; missing data and lack of consideration of the type of IUD, which may have skewed results. Large, prospective studies are needed to confirm the findings observed here to provide insight into any pregnancy-related benefits and long-term benefits of IUDs.

Click to read the study in BJOG

Relevant Reading: Risk of preeclampsia in first and subsequent pregnancies: prospective cohort study

In-Depth [case-control study]: This study explored the impact of prior IUD use on the risk of developing preeclampsia in a subsequent pregnancy among women who developed preeclampsia (n = 2744) and women who did not (n = 11156 controls). Cases were defined as pregnancies affected by preeclampsia, eclampsia, HELLP syndrome, and preeclampsia superimposed on pre-existing hypertension. The primary exposure of interest was prior IUD use. The interval from IUD removal to pregnancy was also measured.

Women who previously used an IUD were less likely to develop preeclampsia in a future pregnancy (OR 0.76, CI 0.58-0.98). This protective effect was greater among women who had their IUD removed within 12 months of pregnancy (OR 0.68, CI 0.46-1.00) and nulliparous women (OR 0.64, CI 0.44-0.93).

Image: PD

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