Ectopic pregnancy in women with recurrent miscarriage

The aim of this study was to investigate the possible association between recurrent miscarriage (RM) and ectopic pregnancy (EP).

In this case-control retrospective study, the clinical cards of women followed as outpatients in the RM and low-risk pregnancy offices of the Obstetrics and Gynecology Unit at the Policlinico Tor Vergata University Hospital were carefully reviewed for the occurrence of EP.

Overall, 598 women with RM and 2043 normal women without RM (controls) were included in the study. Among these women, 4974 pregnancies were analyzed, in which 2028 miscarriages occurred. The EP rate (3.51%) was significantly higher in RM than in control women (1.51%) [odds ratio = 2.31 (95% confidence interval: 2.3-2.4)]; it was particularly high in women with primary RM (5.11%). However, when EP rates were calculated not by women but by overall pregnancies, no differences could be found between RM and control women. In control women, the absence of a miscarriage in the reproductive history was associated with a lower rate of EP.

Women with RM, particularly primary RM, are at increased risk of EP. This increased risk seems to be dependent on the high number of pregnancies occurring in women with RM rather than to specific characteristics of these women.