A review of the effects of long-acting progestogen-only contraceptives on ovarian activity

Rate, extent, and modifiers of spermatogenic recovery after hormonal male contraception: an integrated analysis

BACKGROUND

Hormonal methods for safe, reliable, and reversible contraception based on the suppression of spermatogenesis could soon become available. We have investigated the rate, extent, and predictors of reversibility of hormonal male contraception.

METHODS

We undertook an integrated multivariate time-to-event analysis of data from individual participants in 30 studies published in 1990-2005, in which sperm output was monitored every month until recovery. The primary outcome was the time for the sperm concentration to recover to a threshold of 20 million per mL, an indicator of fertility. We undertook univariate and multivariate analyses, using Kaplan-Meier and Cox's methods.

FINDINGS

1549 healthy eugonadal men who were white (n=965), Asian (almost all Chinese men; n=535), or of other origins (n=49) and aged 18-51 years underwent 1283.5 man-years of treatment and 705 man-years of post-treatment recovery. These data represented about 90% of all published data from individuals using androgen or androgen-progestagen regimens. The median times for sperm to recover to thresholds of 20, 10, and 3 million per mL were 3.4 months (95% CI 3.2-3.5), 3.0 months (2.9-3.1), and 2.5 months (2.4-2.7), respectively. Multivariate Cox's analysis showed higher rates of recovery with older age, Asian origin, shorter treatment duration, shorter-acting testosterone preparations, higher sperm concentrations at baseline, faster suppression of spermatogenesis, and lower blood concentrations of luteinising hormone at baseline. The typical probability of recovery to 20 million per mL was 67% (61-72) within 6 months, 90% (85-93) within 12 months, 96% (92-98) within 16 months, and 100% within 24 months.

INTERPRETATION

Hormonal male contraceptive regimens show full reversibility within a predictable time course. Various covariables affect the rate but not the extent of recovery, although their effect sizes are minor. These data are crucial for the further safe and practical development of such regimens.

An integrated analysis of vaginal bleeding patterns in clinical trials of Implanon

The vaginal bleeding patterns observed during the use of the single-rod progestin-only implant, Implanon, compared with those seen during the use of the six-capsule implant, Norplant, have been analyzed. The acceptability of these bleeding patterns was also assessed. An integrated analysis of 13 different trials was done, studying reference periods (RP) of 90 days. These trials included totals of 1716 Implanon users and 689 Norplant users. There were statistically significant lower mean values over RP 2-8 the range over RP 2-8 is presented) for Implanon, for the number of bleeding-spotting days (15.9-19.3 vs 19.4-21.6; p = 0.0169), the number of bleeding days (7.5-10.0 vs. 11.7-13.1; p < 0.001), and the number of bleeding-spotting episodes (2.2-2.7 vs. 3.1-3.3; p < 0.0001). The bleeding patterns of Implanon users appeared to be more variable than those observed with Norplant: Implanon users had more amenorrhea, and slightly more infrequent bleeding, frequent bleeding, and prolonged bleeding than Norplant users. The difference was only statistically significant for amenorrhea (17.9%-24.8% with Implanon compared with 2.0%-7.0% for Norplant over RP 2-8). There were no statistically significant differences in the acceptability of the two products as indicated by the discontinuation rates, which were 30.2% and 0.9% in Europe and Southeast Asia, respectively, for Implanon, and 22.5% and 1.4%, respectively, in the two regions, for Norplant. The individual bleeding pattern was not predictable. However, in general, it can be stated that women initially without bleeding or with infrequent bleeding have only a small chance of becoming frequent bleeders, and vice versa. Dysmenorrhea clearly improved during use of both Implanon and Norplant. Neither Implanon nor Norplant caused anemia.

The comparative trial of TCu 380A IUD and progesterone-releasing vaginal ring used by lactating women

The objective of this paper was to compare the efficacy, acceptability, safety, and bleeding pattern of TCu 380A intrauterine device (IUD) and progesterone-releasing vaginal ring used by breastfeeding women. The study population included 97 breastfeeding women using IUD and 100 women using vaginal ring. Of the IUD users, no insertion failure, perforation, or accidental pregnancy occurred in 12 months. There was one IUD expulsion. There were no discontinuations of IUD due to medical reasons other than expulsion. The total discontinuation rate was 2.3%. In the ring group, no accidental pregnancy occurred. The major reasons for discontinuation were ring use-related problems and vaginal problems. The total discontinuation rate was 65.4% within 1 year. The frequency of any one complaint among the ring users was higher than that among the IUD users. There were no differences in the proportion of women having no sexual activity and in the weight of their babies between the two groups. Compared with the IUD users, the median number of bleeding/spotting (B/S) episodes and B/S days of the vaginal ring users were fewer; consequently, the mean length of B/S-free interval was longer in all four reference periods; the mean length of B/S episode and segment were the same; the occurrence of amenorrhea was more frequent; in contrast, the proportions of normal bleeding patterns were fewer. The frequencies of prolonged bleeding, frequent bleeding, and infrequent bleeding patterns did not differ between the two groups. The percentage of irregular bleeding was fewer only in the first two reference periods. It is concluded that the TCu 380A IUD and progesterone-releasing vaginal ring used by breastfeeding women are safe and effective. The higher discontinuation rate of the ring users was mainly because of use-related problems. Breastfeeding women with TCu 380A IUD had better tolerance and acceptability. The TCu 380A IUD does not, but the progesterone-releasing vaginal ring does, suppress the recovery of ovarian function. However, once return of menstruation occurred, there were no differences in bleeding patterns between the two contraceptive methods.

Effect of preovulatory insertion of Norplant implants over luteinizing hormone secretion and follicular development

OBJECTIVE

To determine whether the process of ovulation could be interrupted by the insertion of Norplant implants (Leiras Pharmaceuticals, Turku, Finland) in the advanced preovulatory phase.

DESIGN

Prospective study.

SETTING

The Department of Biomedical Research at the Family Planning Clinic of PROFAMILIA, Santo Domingo, Dominican Republic.

PATIENTS

Healthy women of reproductive age, requesting Norplant implants contraception. Thirteen of 15 women volunteers who were admitted completed the study.

INTERVENTIONS

Norplant implants were inserted when the dominant follicle reached a mean diameter of 16 mm, based on serial vaginal ultrasounds (US) beginning on day 10 of the cycle. Blood samples for determination of E2, P, LH, and levonorgestrel, were taken and vaginal US performed at 0, 4, 24, 48, and 72 hours after insertion. If follicle rupture had not occurred at 72 hours after insertion, blood sampling and US were done three times per week during 2 additional weeks.

RESULTS

Follicle rupture occurred in 11 of 13 subjects within 72 hours after insertion, with the exception of 1 subject in whom rupture occurred between 72 and 192 hours. Two women already had an LH peak at the time of insertion. In 9 of the remaining 11 women, a shortlasting, blunted LH surge was observed at 4 hours postinsertion. In the remaining two women, who had the lowest E2 levels, ovulation was inhibited, and a persistent follicle developed without luteinization.

CONCLUSIONS

The insertion of Norplant implants in the advanced follicular phase will not inhibit ovulation if sufficient E2 priming has occurred. On the contrary, the exogenous progestin may rapidly foster ovulation shortly after.