BACKGROUND AND PURPOSE: 

• Whether endometriosis is associated with worse pregnancy outcomes is still unclear 
• Marcellin et al. (JAMA Network Open, 2022) evaluated the association between the presence of endometriosis and preterm birth

METHODS: 

• Multicenter, prospective cohort study 
  • 7 academic units in France  
• Participants 
  • Singleton pregnancies  
  • Follow-up <22 weeks’ gestation  
  • Neonates delivered ≥22 weeks’ 
• Exposures 
  • Endometriosis: Documented history with 3 possible phenotypes 
    • Isolated superficial peritoneal endometriosis (SUP) 
    • Ovarian endometrioma (OMA; potentially associated with SUP) 
    • Deep endometriosis (DE; potentially associated with SUP and OMA) 
  • Control: No clinical endometriosis symptoms  
• Study design 
  • Association between endometriosis and the primary outcome was assessed through univariate and multivariate logistic regression analyses 
  • Adjusted for preterm risk factors 
    • Maternal age | BMI before pregnancy | Country of birth | Parity | Previous cesarean delivery | History of myomectomy and hysteroscopy, and preterm birth 
  • The same analysis was performed according to the 3 endometriosis phenotypes  
• Primary outcome 
  • Preterm birth between 22w0d and 36w6d 

RESULTS: 

• 1351 study participants 
  • Mean (SD) age 32.9 (5.0) years 
  • Endometriosis diagnosis: 470 participants 
    • SUP: 10.2% 
    • OMA: 17.7% 
    • DE: 72.1% 
• There was no difference in the rate of preterm birth between groups 
  • Endometriosis: 7.2% 
  • Control: 6.0% 
  • P=0.38 
• After adjustment, endometriosis was still not associated with preterm birth 
  • aOR 1.07 (95% CI, 0.64 to 1.77) 
• Results were comparable across different disease phenotypes (P=0.84) 
  • SUP: 6.2% preterm birth  
  • OMA: 7.2% preterm birth 
  • DE: 7.4% preterm birth 

CONCLUSION: 

• In this cohort, there was no association between endometriosis and incidence of preterm birth 
• Endometriosis phenotype did not modify this finding 
• The authors state 

Pregnant women with endometriosis should not be considered to have an exceptionally high risk for preterm birth; thus, monitoring their pregnancy beyond the normal protocols or changing management strategies may not be warranted 

Learn More – Primary Sources: 

Association Between Endometriosis Phenotype and Preterm Birth in France