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Tubal pregnancy subsequent to transperitoneal migration of spermatozoa.


 All available English, French, and German literature published prior to January 1978 in which post-sterilization tubal pregnancy was reported was surveyed. From 1957 on, the Index Medicus or Current List of Medical Literature was surveyed for reported sterilization failures. Additional references cited in the literature on tubal pregnancy not associated with prior sterilization were evaluated. A total of 127 pregnancies was collected. Among the 91 specifically mentioned as being tubal, the incidence of pregnancy distal to the site of sterilization was 5 times that in the segment proximal to the site of sterilization. Among the 41 distally located pregnancies, a morphologic description of the site of sterilization was not reported in 30 cases. In these, recanalization of the pregnant tube could have occurred and, therefore, transperitoneal migration of the fertilizing spermatozoon could neither be established nor excluded. In 15 of the 30 cases, recanalization of the pregnant tube was the only etiology considered, and a stenotic area of the site of sterilization, sufficiently wide to permit the passage of sperm but not the passage of ova, was postulated; in 7 cases, the possibility of a fistula as well as recanalization was suggested and in the remaining 8, the etiology was not considered at all. Among the remaining 11 distally located pregnancies, in only one was the site of sterilization evaluated with both patency-testing and microscopic study. In this case, luminal continuity of the pregnant tube was demonstrated, which could have allowed normal sperm transport on that side. A total of 1528 reported tubal pregnancies were selected from the literature for analysis. The presence of complete luminal obliteration proximal to the site of implantation was definitely stated in only 3 cases, while the lumen was found almost completely occluded in 18. In addition to the 3 cases of isthmic obliteration, a pregnancy within a rudimental ampulla and 1 in an ectopically located tube establish that ectopic pregnancy can in fact occur within a tubal segment which does not communicate with the uterus in the absence of previous sterilization. Practical implications in regard to the practice of sterilization, conservative surgical management of tubal pregnancy, and tubal surgery for sterilization reversal are considered, including the advantages of the use of the Irving or Uchida method over the Pomeroy method.
