Are Miscarriages and Pregnancy Complications Related, and is There a Waiting Period Before Trying to Conceive Again?

According to research, pregnancy within three months of a miscarriage or abortion is not associated with an increased risk of pregnancy complications. The study suggests that, contrary to current recommendations, women can become pregnant again after a miscarriage or abortion without increased perinatal risk, reassuring those who wish to try earlier than recommended in the guidelines. In addition, researchers are investigating whether miscarriages are associated with later pregnancy complications.

Pregnancy Interval After Miscarriage or Abortion

The World Health Organization recommends waiting six months after a miscarriage or abortion before trying to conceive again to avoid complications in the next pregnancy. However, there is little evidence to support this. Gizachew Tessema of the Curtin School of Population Health in Australia and his colleagues conducted a cohort study of a total of 49,058 births after miscarriages and 23,707 births after abortions in Norway between 2008 and 2016. They examined six adverse outcomes: preterm birth, spontaneous preterm birth, low birth weight for gestational age, high birth weight for gestational age, preeclampsia, and gestational diabetes.

Compared to a waiting period of 6 to 11 months after a miscarriage, the risk of low birth weight for gestational age (age of the unborn child or newborn from the presumed date of conception) in babies conceived within less than six months was lower, and the risk of gestational diabetes was lower in women who became pregnant within less than three months. After an abortion, there was a slight but not significant increased risk of pregnancy with a baby that was too small for gestational age when conception occurred within less than three months compared to 6–11 months, but the risk of a baby that was too large for gestational age was lower in the group with an interval between pregnancies of 3–5 months.

There was no evidence of an increased risk of adverse pregnancy outcomes in women with an IPI of more than 12 months after miscarriages or induced abortions, with the exception of a slightly increased risk of gestational diabetes. The authors acknowledge that the study is limited in that information on potential confounding factors, including pregnancy intention and health behaviors, was lacking. In addition, the data only included miscarriages recorded through the healthcare system. The findings do not support current guidelines to wait six months after a miscarriage or abortion and suggest that these guidelines need to be reviewed and current, evidence-based recommendations provided to women.

Miscarriages and Pregnancy Complications

A study by Curtin University has found a link between miscarriage and an increased risk of complications from gestational diabetes and high blood pressure in later pregnancies. Researchers at the Curtin School of Population Health analyzed 52 studies involving more than 4 million pregnancies in 22 countries to examine the health effects of miscarriage, abortion, and recurrent pregnancy loss (more than two consecutive miscarriages) on subsequent pregnancies. The study found different health risks for each group.

Women who had experienced a miscarriage had a 44 percent higher risk of developing gestational diabetes in later pregnancies, but only a 6 percent higher risk of developing high blood pressure in subsequent pregnancies. Conversely, women who had experienced recurrent miscarriages did not show an increased risk of gestational diabetes, but they did have a 37 percent higher risk of developing preeclampsia in later pregnancies, a potentially dangerous complication characterized by high blood pressure. There was no evidence that abortions were associated with diabetes or high blood pressure, either during or outside of pregnancy. Lead study author Dr. Jennifer Dunne said that finding a link between miscarriage, diabetes, and high blood pressure could have far-reaching implications.

Further research into the biological links between miscarriage and later health problems could provide new avenues for developing treatments. According to the researchers, the study adds to existing knowledge about pregnancy complications and health later in life, even beyond pregnancy. By shedding light on the long-term health effects of miscarriage and recurrent pregnancy loss, this study paves the way for improved health strategies, research, and support for those affected—and hopefully better outcomes for parents and babies in future pregnancies.