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Background: Although public health programs invest heavily in the male latex condom, its efficacy in preventing pregnancy and sexually transmitted disease has been based primarily on in vitro and retrospective studies., Methods: We combine the results from two randomized, controlled contraceptive efficacy trials that used commercial latex condoms brands (Ramses Sensitol, LifeStyles, Trojan-Enz) in the control arms. Combining data from the two studies, we obtained longitudinal data covering 3526 menstrual cycles contributed by approximately 800 couples who used latex condoms exclusively for up to six menstrual cycles. Both trials also collected 3715 detailed breakage and slippage reports from the first five study condom uses. The second trial also tested 243 postcoital vaginal samples collected after the first study condom use for the presence of prostate-specific antigen (PSA) and spermatazoa., Results: The combined clinical breakage rate for the first five condom uses was 0.4% for the three latex brands and the combined clinical slippage rate was 1.1%. The combined six-cycle typical-use pregnancy rate for the latex condoms was 7.0% (95% confidence interval 5.0-9.0). The combined six-cycle consistent-use pregnancy rate was 1.0% (95% confidence interval 0.0-2.1). PSA was detected in only 1.2% of postcoital vaginal samples collected after the first use of an intact study condom. There were no differences in performance or efficacy among the three latex brands tested., Conclusions: The male latex condoms rarely broke or slipped off during intercourse and provided high contraceptive efficacy, especially when used consistently. Risk of semen leakage from intact condoms was very low.

Accurate measurement of semen exposure resulting from condom failures can refine public health messages and improve predictions of condom efficacy in preventing pregnancy and HIV transmission. Eight hundred and thirty couples enrolled in a condom efficacy study were asked to collect a baseline sample of ejaculate from the inside of the first study condom they used and to collect a postcoital vaginal sample whenever a study condom broke or slipped off during intercourse. All samples were quantitatively tested for prostate-specific antigen (PSA), a substance found only in human semen, using rocket immunoelectrophoresis, and inspected microscopically for presence of sperm. Sixty-eight baseline ejaculate samples collected from the inside of the first study condom by couples who subsequently experienced a condom failure averaged 13.4 microg PSA per swab and 79% of the samples averaged one or more sperm per high power field (hpf). Seventy-nine postcoital vaginal samples obtained after a condom break averaged 5.7 microg PSA per swab and only 38% averaged one or more sperm per hpf. The PSA results indicated a 50% reduction in semen exposure compared to baseline levels (p = 0.0001). Seventeen samples obtained after a condom slip-off averaged 2.5 microg PSA per swab and none of the samples averaged one or more sperm per hpf. The PSA results indicated an 80% reduction in semen exposure compared to baseline levels (p = 0.0001). Our results suggest that even condoms that fail reduce the risk of pregnancy and the transmission of sexually transmitted disease compared to unprotected intercourse. We also used PSA results to adjust a model designed to predict consistent-use pregnancy rates from condom breakage and slippage data.

The ability of condoms to retain all elements of semen during intercourse has been assessed by postcoital visual inspection and in vitro permeability studies. Yet, these observations may not be sufficiently precise or realistic. This pilot study evaluated prostate-specific antigen (PSA) as a semen marker of inapparent failure of the condom barrier under conditions of actual use. Twelve couples collected samples from the vagina and surfaces of the condom using sterile cotton swabs. We obtained precoital and postcoital samples for 24 acts of unprotected intercourse, 54 acts of intercourse using intact condoms, and 40 acts of intercourse using condoms that had been deliberately punctured. We used electrophoresis to determine the amount of PSA present in the samples. PSA was detected in 100% (24/24) of vaginal samples collected immediately after unprotected intercourse and in none of the vaginal samples collected more than 24 h after intercourse (0/90). PSA was also present in 98% (83/85) of the samples collected from the inside of the condom that had failed during intercourse. Excluding uses where the condom failed during intercourse, PSA was detected in 2% (1/47) of the postcoital vaginal samples collected after use of intact condoms and in 41% (14/34) of the samples collected after use of condoms with known 1-mm punctures. We conclude that PSA shows great promise as a semen biomarker in clinical trials of barrier methods. We recommend that future studies further investigate the ability of this biomarker to identify condom failures and quantify the extent of semen exposure associated with various types of condom failures.

A procedure for the multisystem analysis of bloodstains using the simultaneous separation of the enzymes glyoxalase I, esterase D, and phosphoglucomutase has been developed. The amount of bloodstain required has therefore been reduced threefold without any loss in resolution and sensitivity. Bloodstains at least seven weeks old have been correctly phenotyped in all three systems.

A bloodstain extraction procedure that improves the analysis of haptoglobin in dried bloodstains has been developed. The streaking of electrophoresis gels caused by deteriorated hemoglobin can be eliminated by incorporating chloroform in the bloodstain extraction procedure. The method is easier to execute than previously published techniques for eliminating the adverse effects of deteriorated hemoglobin on the analysis of haptoglobin. Bloodstains up to two years old were correctly phenotyped in haptoglobin by this method.