By I.Soussis MD
If women suffering with endometriosis have a higher risk of adverse pregnancy outcome in early pregnancy, such as spontaneous miscarriage or ectopic pregnancy, was not well documented up to now.
A study from Japan compared 49 pregnant women with endometriosis to 59 without the disease. They found that the incidence of spontaneous miscarriage was not statistically significant different among the two groups. (18,4% in women with and 18,6% in women without endometriosis). Obviously in this study the numbers are small and its statistical power is rather weak.
Aris studied the impact of endometriosis on adverse pregnancy outcome in the Eastern Townships of Canada, over a 12 year period. The pregnancies studied were 31068 and of those 784 were in women with endometriosis (2,5%). In 183/784 pregnancies in women with endometriosis, an adverse outcome was recorded (23,3%). The risk of spontaneous miscarriage in women with endometriosis was statistically significant higher than the general population. The risk of miscarriage was almost twice than in women without endometriosis (1,89).
Saraswat et al. presented in Lisbon at the annual meeting of ESHRE 2015, an extremely interesting linkage analysis of the Scottish national registry. They studied 14655 women discharged from all Scottish national hospitals over a period of 30 years (1981-2010). They compared the pregnancy outcome in 5375 women with surgically confirmed endometriosis to 8280 women without endometriosis, who were pregnant at the same period. The chance of adverse pregnancy outcome in the first trimester was significantly higher in women with endometriosis. More specific the risk of spontaneous miscarriage was 1,7 and the risk of ectopic pregnancy was 2,7 times higher, than in women without endometriosis.
The statistical power of the last two studies is extremely strong. Indeed Saraswat et al. studied the whole population of Scotland over a long period of time.
Conclusions: The presence of endometriosis increases the risk of spontaneous miscarriage and ectopic pregnancy. Women with endometriosis should be followed closely in the first trimester of pregnancy. They should also be informed of the increased chances of adverse pregnancy outcome.
Eur J Obstet Gynecol Reprod Biol. 2014 Jan;172:36-9. doi: 10.1016/j.ejogrb.2013.10.024. Epub 2013 Oct 31. Endometriosis and pregnancy outcome: are pregnancies complicated by endometriosis a high-risk group? Mekaru K1, Masamoto H2, Sugiyama H2, Asato K2, Heshiki C2, Kinjyo T2, Aoki Y2.
Gynecol Endocrinol. 2014 Jan;30(1):34-7. Doi:10.3109/09513590.2013.848425. Epub 2013 Oct 17. A 12 year cohort study of adverse pregnancy outcome in Eastern Townships of Canada: impact of endometriosis. Aris A.
ESHRE 2015, O-122. Reproductive and pregnancy outcomes in women with endometriosis: a Scottish national record linkage study L.Saraswat, D.Ayansina, S.Bhattacharya, D.Miligkos, A.Horne, K. Cooper, S. Bhattacharya.