Endometriosis in Pregnancy: Risks, Complications, and Screening

Jun 4, 2025

Author: Dr. Mark Noar

Postpartum Hemorrhage Risks in Endometriosis-Affected Pregnancies

Postpartum hemorrhage (PPH), commonly defined as a blood loss of 500 ml or more within 24 hours after birth, is the leading cause of maternal mortality worldwide. Each year, about 14 million women experience PPH resulting in about 70,000 maternal deaths globally.[1]  Even when women survive, they often need urgent surgical interventions to control the bleeding and may be left with long-term consequences, both physical (e.g., life-long reproductive disability, bladder injury, postpartum infection, anemia), and psychological (e.g., post-traumatic stress disorder). The risk of PPH and PPH-related morbidity and mortality disproportionately affects women who lack access to quality care.

Acute pregnancy-related endometriosis problems as well as post-partum complications have been reported. These problems can be life-threatening to both the mother and the fetus. Acute pregnancy-related complications are rarely reported and underestimated, while the more common postpartum complications are well known.[2–8]

Common Obstetric Complications Related to Endometriosis

  • First-trimester abortion (miscarriage)
  • Ectopic pregnancy
  • Premature labor/premature rupture of membranes
  • Small birth weight for gestational age (SGA)
  • Intrauterine growth retardation / Fetal Growth Restriction
  • Hypertensive disease of pregnancy and pre-eclampsia
  • Placenta previa
  • Obstetric bleeding
  • Bowel complications

Interestingly, a specific association between rectovaginal endometriosis and placenta previa has been observed.[9,10].

Literature Highlights

Miscarriage:
A 2016 study found that out of a group of 478 women, 139 women with endometriosis reported a history of miscarriage. A group of 964 women without endometriosis only reported 187 cases of miscarriage.[11–13]  Zullo, in 2017, showed that endometriosis could be characterized as a decisive predisposing factor for first-trimester miscarriage.[14]

Ectopic Pregnancy:
Ectopic pregnancy has a normally recognized rate of spontaneous conception reaching 1–1.5%. Farland’s study noted endometriosis-affected women are at a risk up to six times higher than women without endometriosis.[15]

Premature Labor:
A higher risk of premature birth has been documented in the literature.[16–18]  This risk may be as high as twice the risk in women without endometriosis.[19]  There is a heightened risk for preterm delivery and an increased risk of premature rupture of fetal membranes.[20,21]

Intrauterine Growth Retardation / Fetal Growth Restriction:
There is a potential link between endometriosis and IUGR, demonstrated by Nirgianakis, reporting that women with a history of endometriosis, regardless of the degree of penetration, are at increased risk compared to healthy women.[22]
By definition, two standard deviations below the average weight at the corresponding gestational age can be used.[23,24]

Hypertensive Pregnancy Disorders / Pre-eclampsia:
The risk of pre-eclampsia in women with endometriosis shows no statistically significant increase, affecting 5% of pregnancies. The correlation between hypertension during pregnancy and endometriosis does not show a discernible variation in the risk of gestational hypertension.[14,19]  However, multiple studies have found that patients with advanced-stage or non-advanced stage typically exhibit preeclamptic signs more frequently than women without the condition.[19,31]

Placenta Previa:
The occurrence of placenta previa is heightened four-fold in women affected by endometriosis.[13]   The presence of endometriosis increases the likelihood of placenta previa.[25]

Obstetrical Bleeding:
Painless vaginal bleeding during the second and third trimesters is a clinical symptom of abnormal placenta implantation.
Antepartum hemorrhage is up to 80% more prevalent in women with endometriosis, and its incidence is ten-fold higher in those with deep endometriosis. Postpartum bleeding occurs 1.3 times more frequently in afflicted women.[3,26]
Studies show a statistically significant elevation in the risk of postpartum hemorrhage among women with endometriosis compared to controls.[27–29]  This risk is consistent regardless of the degree of penetration.[22]

Bowel Complications:
Significant intestinal issues, particularly bowel perforation in the third trimester or during IVF stimulation, have been noted in women with deep endometriosis. Prevalence remains uncertain, likely due to underreporting.[30]

Growing Awareness

Until recently, the significance of endometriosis-associated obstetrical complications has been underappreciated. The WHO Roadmap to Combat Postpartum Hemorrhage 2023–2030 has brought attention to this issue in an effort to reduce fetal and maternal mortality.[32]

The Path Forward

Historically, the approach has been focused on knowledge and anticipation. If endometriosis is known prior to pregnancy, early complications can be anticipated and managed in appropriate care settings. However, no screening test existed until recently that was noninvasive, portable, accurate, and widely accessible.

Testing, Treatment, and Prevention

In 2022, a new biomarker—GIMA—was identified after over a decade of research that began in 1998.[33]   This led to the development of the Endosure Test, the first and only noninvasive, portable, 30-minute test with over 99% accuracy across all disease stages. It requires only potable water and reclining quietly during testing. No professional degree or invasive procedures are necessary.

The Endosure Test:

  • Decentralizes diagnosis
  • Removes geographic and financial barriers
  • Enables real-time monitoring after treatment
  • Is supported by peer-reviewed studies[34,35]

A New Standard of Care

The Endosure test identifies women who may need:

  • Closer monitoring during pregnancy
  • Specialized care during labor and delivery

Even more promising is the pairing of diagnosis with treatment. A recent study shows that Dienogest, when used pre-pregnancy, can significantly reduce complications associated with endometriosis.[36]

For the first time, there’s real hope: to identify, treat, and monitor women at risk—offering not just answers, but better outcomes.[37](Unpublished internal data)

 

References

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