Female sterilization procedures, particularly laparoscopy and minilaparotomy are both safe and effective. Most evaluations of the safety of sterilization have focused on the short-term complications and complaints associated with the procedures, but some researchers have looked at long-term effects. Concern has been expressed that sterilization may be related to subsequent disturbance of menstrual patterns to such a degree that hysterectomy or other surgical treatment is required.
Family Health International (FHI) collected data on menstrual patterns during clinical trials at 45 hospitals in 23 countries. Menstrual pattern changes were examined for 1550 interval women (more than 42 days postpartum or post abortion) who sought sterilization for contraceptive purposes, who were aged 25-34 years old and who had between two and six live births. Women were asked at the time of the sterilization procedures about the characteristics of their three most recent menstrual cycles. These questions were repeated at all follow-up visits.
Four variables of the menstrual cycle were studied: regularity (regular or irregular); length of cycle (in days); duration of bleeding (in days); and dysmenorrhea (none, mild, moderate, severe).
Research has shown that use of certain contraceptives before sterilization can influence post-sterilization menstrual patterns:
Former pill users have an increase in flow and in dysmenorrhea (menstrual pain) and irregularity, usually caused by stopping the pill and not by the operation.
Former IUD users experience decreased flow and dysmenorrhea; and again, these changes are probably caused by the termination of IUD use, not by the sterilization procedure.
Users of barrier methods report minimal disruption of menstrual patterns.
Because previous contraceptive use can influence pre-sterilization menstrual patterns, none of the women selected for this study were using hormonal or intrauterine contraception in the three months immediately before the sterilization.
Results
The majority of the women in the FHI study experienced no change in the 12 months following sterilization, and among those who did, changes in one direction were counterbalanced by changes in another direction. Specifically:
87 percent of the women had no change in regularity of cycles; more women became regular than became irregular.
61 percent of the women had no change in cycle length of more than two days; 20 percent reported shorter cycles; and 19 percent reported longer cycles.
52 percent of the women had no more than one day's change in duration of menstrual bleeding; 26 percent reported shorter menstrual periods; and 22 percent reported longer menstrual periods.
70 percent reported no change in dysmenorrhea; 17 percent reported less pain; and 13 percent reported more pain.
Women were separated according to whether their menstrual cycles were "normal" or "abnormal" at admission. This was done to see whether women with abnormal menstrual patterns were more or less likely to experience change. Normal was defined rather broadly: regular cycles with a length of 28 plus or minus 7 days, duration of bleeding of 2-7 days, and no more than mild dysmenorrhea. Women outside one or more of these parameters at the time of the sterilization procedures were defined as having an abnormal menstrual pattern; 21 percent were so defined.
Abnormality was the best predictor of change when all women were considered. Women with abnormal menstrual patterns at the time of sterilization were more likely to experience change in their menstrual patterns than women with normal patterns.
Percentage distribution of the number of menstrual pattern changes experienced at 12 months after sterilization for women with normal and abnormal menstrual patterns at admission.
No. of changes
Normal at admission (%)
Abnormal at admission (%)
All women
%
N
No change
61.9
20.4
53.3
830
One change
29.3
51.0
33.8
525
Two changes
8.2
24.2
11.5
179
Three changes
0.6
4.4
1.4
21
Total (%)
100.0
100.0
100.0
N
1,237
318
1,555
Other findings:
Both tubal rings and spring-loaded clips were associated with less change than the other methods of tubal occlusion, and ligation with excision was associated with more change. However, this difference was small and of little clinical significance.
Surgical difficulties in performing the procedure had no demonstrable effect on change in the menstrual pattern.
Complications during surgery or in the postoperative period did not appear to affect change in menstrual pattern.
Although none of these women was scheduled to have concurrent surgery, a number underwent surgery in addition to tubal sterilization to treat conditions discovered at the time of the procedure. Concurrent surgery neither increased nor decreased the likelihood of change in the menstrual pattern.
Conclusion
Among women using neither hormonal nor intrauterine contraception before the sterilization, slightly more than half reported no change in their menstrual patterns a year after their sterilization operation. A substantial minority (47 percent) did report change. The changes included improvements in some parameters as well as changes for the worse. For example, more women reported that dysmenorrhea had decreased than reported that it increased. More women reported their menstrual patterns became regular than irregular.
In general, women whose menstrual patterns are abnormal at the time of the sterilization procedure are more likely to experience change than women with more average menstrual patterns.
