Luteal phase pregnancies in female sterilization patients.

Little is known of the incidence, predictors or outcomes of luteal phase pregnancies (LPPs) in women presenting for voluntary interval female sterilization. A series of 37 LPPs was identified from a large multicenter female sterilization data set. Each LPP case was matched with two nonpregnant (NP) controls for clinic, operator, surgical approach, tubal occlusion technique and date of surgery. The LPP cases did not have a distinct demographic or clinical profile, but were generally more fecund than NP controls. LPPs were further compared with a second unmatched group consisting of 123 true sterilization failures (TSFs), pregnancies conceived after sterilization. Women with LPPs were more likely to have their pregnancies confirmed and/or terminated in the second trimester than were women with TSFs. The majority of LPPs were carried to term; the majority of TSFs ended in induced abortion. There were 12 ruptured ectopic pregnancies among the TSFs and none among the LPPs. Programmatic implications of the results are discussed.