ESHRE2015: Endometriosis associated with a greater risk of complications in pregnancy

Nationwide analysis of more than 14,600 women show that rates of miscarriage and ectopic pregnancy is higher in women with endometriosis.

Data presented at ESHRE2015 by Dr Lucky Saraswat show that women with endometriosis have an increased risk of miscarriage and ectopic pregnancy; and women with a history of endometriosis, whose pregnancies progressed beyond 24 weeks, were found to be at a higher than average risk of complications, including haemorrhage (ante- and postpartum) and preterm birth [1].

In the general population one in five pregnant women are likely to miscarry. This study shows that in women with endometriosis this risk is increased to about one in four.

Ectopic pregnancy is rarer, at one in 100, but in women with endometriosis this risk is more than doubled.

Endometriosis and pregnancy

Whereas – anecdotally – we have been aware for some time that pregnancies may be more complicated for women with endometriosis, the impact of endometriosis on pregnancy outcomes has been relatively unexplored.

Population based studies on endometriosis are challenging to perform because the disease can only be diagnosed with certainty by laparoscopy. The existing literature is, therefore, not without limitations, and opinion among previous studies is not only divided, but surgical confirmation of endometriosis have not always been possible.

ESHRE 2015

Dr Lucky Saraswat, a consultant gynaecologist from Aberdeen Royal Infirmary (UK), and her co-investigators therefore conducted this study to evaluate reproductive and pregnancy outcomes in women with a confirmed surgical diagnosis of endometriosis.

Using discharge data from all state hospitals in Scotland this nationwide cohort study included records of women with and without a surgically confirmed diagnosis of endometriosis, who were cross-linked to their maternity records in order to evaluate pregnancy outcomes.

A total of 14,655 women were included in the analysis, with their medical records followed-up for a maximum of 30 years between 1981 and 2010. The study group then compared the reproductive and pregnancy outcomes in 5,375 women with surgically confirmed endometriosis with those of 8,280 women without endometriosis, who were pregnant at the same time.

After adjustments for age and previous pregnancy, results showed that women with endometriosis had a significantly higher risk of early pregnancy complications than the controls. This risk was 76% higher for miscarriage (odds ratio 1.76) and nearly three times higher for ectopic pregnancy (OR 2.7).

In women with a previous diagnosis of endometriosis the risks of adverse pregnancy outcomes, including ante- and postpartum haemorrhage and preterm birth, was also significantly increased.

Why are women with endometriosis at higher risk during pregnancy?

Suggesting a possible explanation for the risk, Dr Saraswat said that endometriosis is associated with increased inflammation in the pelvis, as well as structural and functional changes in the lining of the uterus.

We believe such changes in the pelvic and uterine environment could influence implantation and development of the placenta, which may predispose them to adverse pregnancy outcomes.

she said.

Managing women with endometriosis during pregnancy

It is clear that these findings must be taken into account when counselling women with endometriosis about their family plans and care during pregnancy.

Dr Lucky Saraswat and Professor Andrew Horne at the ESHRE meeting in Lisbon, June 2015

Said Dr Saraswat:

Healthcare strategies for surveillance and early identification of complications in pregnancy are vital in order to optimise outcomes in women and their babies.

We need increased monitoring of women with endometriosis by ultrasound scans, and greater vigilance to identify potential complications such as bleeding and preterm delivery.

Co-investigator Professor Andrew Horne, consultant gynaecologist at the MRC Centre for Reproductive Health of the University of Edinburgh (UK), and the Chair of ESHRE’s Special Interest Group on Endometriosis, said 60-70% of women with endometriosis will get pregnant spontaneously and have children.

However, we do not discuss what happens when they do become pregnant. These new findings suggest that we may need to warn women with endometriosis, who become pregnant, that they are at higher risk of both early and late complications in pregnancy, and that this may warrant increased antenatal monitoring.

said Professor Horne.

  1. Saraswat L, et al. Reproductive and pregnancy outcomes in women with endometriosis: a Scottish national record linkage study. ESHRE2015 Abstract O-122
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