A study of ruptured tubal ectopic pregnancy

Ectopic pregnancy continues to be a leading cause of maternal morbidity and of reduced childbearing potential among women of reproductive age. Because of tubal rupture it is still the main cause of pregnancy-related death during the first trimester. The purpose of our study was to evaluate factors that may predispose a woman to rupture of a tubal ectopic pregnancy.

In this retrospective study of 693 ectopic pregnancies from three McGill University teaching hospitals, we compared risk factors, preoperative ultrasound, and serum hCG levels between cases with ruptured and unruptured tubal ectopic pregnancy.

The age and the number of pregnancies among the two groups of women were similar. The gestational age of women with an unruptured tube was 6.9 +/- 1.9 weeks, and of those with a ruptured tube, the gestational age was 7.2 +/- 2.2 weeks. Tubal rupture was encountered more often in women with at least one child than in childless women. History of ectopic pregnancy was found in 35% of women with an unruptured tubal pregnancy and in 26% of those with a ruptured tube. Serum hCG levels at the time of treatment were not significantly different among the two groups of women. Eleven percent of women with a ruptured tube had serum beta-hCG levels of less that 100 IU/L.

Tubal rupture is encountered more often in women with no history of ectopic pregnancy and in those with at least one child. This suggests that ectopic pregnancy is less suspected in these women. Tubal rupture is encountered less often in ampullary pregnancy and in small ectopic pregnancies. There is no correlation between serum beta-hCG levels and tubal rupture, and rupture can occur even when serum beta-hCG levels are very low.