Varying opinions exist regarding how long a couple should wait before trying again after an early pregnancy loss. A new study should be good news for couples anxious to add a child to their family. The findings were published in the February edition of the journal Obstetrics & Gynecology by researchers at the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland; and the University of Utah, Salt Lake City, Utah.
The study authors note that after an early pregnancy loss couples often seek counseling regarding how long to wait before attempting conception again. Many physicians recommend waiting at least 3 months, and the World Health Organization recommends a minimum of 6 months. However, no data exists that supports these recommendations. In addition, previous studies have shown that the uterus may be more receptive to a pregnancy directly after an early loss. Most studies addressing pregnancy spacing concentrate on the interval between live births and subsequent pregnancies (interpregnancy interval) with the majority of studies noting that an interpregnancy interval of less than 18 months is associated with increased risk for poor maternal and perinatal outcomes.
The authors explain that the optimal timing after a pregnancy less than 20-weeks of pregnancy (excluding tubal or molar pregnancies) is unclear. Therefore, they set out to assess the relationship between the interpregnancy interval and a successful pregnancy outcome. They theorized that there would be no difference in reproductive success among couples who started trying to conceive within compared to greater than three months of their pregnancy loss.
The researchers accessed data from the Effects of Aspirin in Gestation and Reproduction trial, which comprised 1,083 women. Included were women aged 18–40 years with one to two previous early losses and whose last pregnancy outcome was a nonectopic or nonmolar loss. The women were actively followed for up to six menstrual cycles and, for women who achieved a pregnancy, until pregnancy outcome. They calculated intervals as start of trying to conceive date minus pregnancy loss date. Time to pregnancy was defined as start of trying to conceive until subsequent conception. The data were subjected to statistical analysis and adjusted for age, race, body mass index (BMI), education, and subfertility.
The investigators found that couples with a 0–3-month interval (765 [76.7%] couples) compared to a greater than 3-month (233 [23.4%] couples) interval were more likely to achieve live birth (53.2% compared to 36.1%) with a significantly shorter time to pregnancy leading to live birth. In addition, adjusting for low-dose aspirin treatment did not significantly alter estimates.
The authors concluded that their study supports the theory that there is no physiologic evidence for delaying pregnancy attempt after an early loss.