Endometriosis surgery and future pregnancy complications

Endometriosis surgery and future pregnancy complications

Preterm birth, small baby for gestational age, and placenta previa may be more common among women with previous endometriosis surgery.

Key Points



  • Extended surgery for deep infiltrating endometriosis including rectum and bladder may aggravate harmful results.
  • ART regimes additionally jeopardize pregnancy outcomes. 

What's done here:

  • The authors retrospectively investigated 1297 women who had endometriosis surgery and got conceived between June 2006-December 2016 at Rouen University Hospital.
  • 569 patients from that cohort with recorded deliveries after 22 weeks of gestation and who had undergone surgery for endometriosis before conception were enrolled.
  • Newborn status of small for gestational age, spontaneous preterm birth, and placenta previa was the primary outcome.  

Key results:

  • 569 patients conceived at least once after endometriosis surgery during the study period, a total of 739 pregnancies achieved, 422 (57.1%) were natural conceptions
  • Out of the total 566 deliveries (77.2%), 535 were singleton (72.9%), and 31 twins (4.2%).
  • Singleton pregnancies resulted from natural conceptions in 336 (62.8%), and multiple pregnancies resulted from natural conceptions in 4 (12.9%). 
  • In 81 (15.1%) of 535 singleton pregnancies, and in 9 (29%) of 31 twin pregnancies, the baby was small for gestational age.
  • Preterm birth occurred in 53 (9.9%) of 535 singleton pregnancies, and in 19 (61.2%) of 31 twin pregnancies.
  • The occurrence of placenta previa in singleton and multiple pregnancies were 9 of 535 (1.7%) and 0 of 31.
  • The absence of endometriomas was an independent factor for the baby of small for gestational age.
  • Conception with the use of ART, BMI >30 kg/m2, and surgery for deep endometriosis infiltrating the rectum and the bladder were independent factors for increased risk of preterm birth and placenta previa.


  • There is no control group that consists of healthy pregnants to compare the pregnancy outcomes.
  • No information about the patients about primigravida/multiparous status.
  • As the questionnaire was created in 2009, questions focusing on the relationship between endometriosis and other worse obstetrical outcomes are missing.

Lay Summary

Endometriosis is one of the known diseases for infertility in the reproductive period of women. Several studies revealed that endometriosis itself maybe the reason for some unfavorable obstetric outcomes.

Localization, the type of endometriotic lesions, and the stage of endometriosis may affect pregnancy outcomes. Maternal complications can be notified as preeclampsia, antepartum and postpartum hemorrhage, increased number of cesarian sections, spontaneous hemoperitoneum, and bowel perforation. On the other hand, fetal unfavorable outcomes are preterm birth, prematurity, small for gestational age, and stillbirth.

Farella et al., from Milan, Italy, conducted a retrospective study to analyze pregnancy outcomes of women after 22 weeks of pregnancies who had previous surgery due to their endometriosis and recently published it in the journal named "Fertility and Sterility".

During this retrospective study period between June 2006 and December 2016, 1297 patients went to surgery to cure their endometriosis were analyzed. 569 women who conceived at least one time were the subject of the study. A questionnaire about the obstetrical history, including ongoing pregnancies, and delivery outcomes were collected, through the CIRENDO database which is approved by French authority. Using this method the authors analyzed the mode of conception, the time between endometriosis surgery and conception, abnormal placenta localization, the duration of pregnancy, newborn birth weight, and the modality of delivery.

The study group included 569 women who had 739 pregnancies during this period, of which 422 were natural conceptions (57.1 %). The results of the study suggested that despite the complete removal of endometrial lesions due to prior surgery, women who have surgery for endometriosis showed higher complications of pregnancy and delivery. Especially women with deep infiltrating endometriosis invading rectum and bladder had higher rates of preterm births. The logistic regression model revealed that the use of ART also is an independent risk factor statistically associated with the risk of these worse pregnancy outcomes.

The authors concluded their results of higher SGA rates in their study group were due to the operations that were made to the advanced stages and deep localizations of endometriotic cases and the ART methods that applied to these women.

Research Source: https://pubmed.ncbi.nlm.nih.gov/32327240

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