Effect of prior pregnancy and combined oral contraceptives on baseline menstrual blood loss and bleeding response to intrauterine devices

Abstract

No effect of pregnancy was found on baseline menstrual blood loss (MBL) in women within one year of parturition or abortion. The increased bleeding response of women to intrauterine devices (IUDs) was found to be independent of pregnancy status during the year preceding IUD sertion. Women pregnant within a year of insertion had no different MBL than those pregnant more than a year prior to insertion. MBL quantified in subjects within three months of discontinuing combined oral contraceptives (OCs) was significantly lower than in prior non-OC users. Furthermore, MBL was significantly reduced in the former group during the first three menses following IUD insertion. At the sixth and twelfth menses post-insertion, MBL was still lower in prior OC users, but the difference between users and non-users was less and no longer statistically significant.

PIP: The effects of pregnancy and oral contraceptive (OC) use within 1 year of IUD insertion were studied on both preinsertion and postinsertion menstrual blood loss. Of 88 starting subjects, 36 (41%) had not used OCs for the previous 15 months or longer, and had had a pregnancy termination more than (n=21) or less than (n=15) l year of study (nonusers). 52 patients had used OCs (combined-type) for 3 months-13 years before study; they discontinued OCs from 38-88 days before IUD insertion (users). No effect of pregnancy was found on baseline menstrual blood loss in women within 1 year of parturition or abortion. Increased bleeding was found in all women after IUD insertion was independent of pregnancy status; women pregnant within 1 year of insertion had no different menstrual blood loss than those pregnant more than 1 year of prior. The OC user group had significantly lower menstrual blood losstthan prior non-users. Menstrual blood loss was significantly reduced in the OC user group during the 1st 3 menstrual flows after IUD insertion. Though still lower at the 6th and 12th months postinsertion, the difference was no longer statistically significant for either.