Ectopic pregnancy after tubal sterilization
Shah, J.P.; Parulekar, S.V.; Hinduja, I.N.
Journal of Postgraduate Medicine 37(1): 17-20
1991
ISSN/ISBN: 0022-3859 PMID: 1941685 Document Number: 320078
This study of ectopic pregnancy reports an incidence of 13 (4.53%) out of 287 ectopic pregnancies between 1984-89 in a Bombay hospital which occurred after tubal sterilization. 6 had a ruptured ectopic pregnancy, 5 unruptured, and 2 with a chronic ectopic gestation. Bilateral salpingectomy should be performed when exploring for an ectopic pregnancy after sterilization. Although the failure of voluntary sterilization is small, 15-20% are likely to be ectopic pregnancies. In this study, 84.6% occurred 1 year after sterilization. Physicians should be alerted to the possibility of ectopic pregnancy, particularly if 2 or more years have elapsed, because of the maternal mortality risk. The risk of ectopic pregnancy is 12.5% for women undergoing tubal ligation had they continued previous contraception, which is less than observed among normal women. An uncorrected incidence rate of .64/10,000 sterilizations has been reported and 7.7/100 pregnancies conceived after tubal ligation. The explanation given is that recanalization or formation of a tuboperitoneal fistula occurs. The opening is small enough for sperm to pass through but too small for the fertilized ovum, which results in implantation in the distal tubal segment. Another possibility is the formation of blind pouches or slitlike spaces in the abnormal reconstitution of the tubal lumen, which increases the likelihood of ectopic implantation. There may also be development of tuboperitoneal fistulas associated with endometriosis, particularly when the site is within 4 cm of the cornua, which is a probable point of implantation. Fluid movement within the remaining tubal segments may influence implantation. Sterilization was performed in 92.3% of the study patients in conjunction with medical termination of pregnancy or puerperium. When sterilization is performed during the postpartum period, the incidence of ectopic pregnancy is higher because of incomplete occlusion of the tubal lumen due to the edematous, friable, and congested fallopian tubes. A recommended procedure in laparoscopic sterilization to avoid failure of silastic band application is to "milk" the fallopian tube several times by drawing it in and out of the applicator sheath before applying the band. Then, examine carefully for a vertical crease between the 2 limbs of the loop and blanching of the banded tubal segment. Extra caution and meticulous technique are required to avoid failure. Physician and patients awareness about the possibility and risk of extra- and intrauterine gestation following all methods of sterilization is necessary.