Lea's Shield: a study of the safety and efficacy of a new vaginal barrier contraceptive used with and without spermicide

The purpose of this study was to evaluate the safety, efficacy and acceptability of Lea's Shield, a new vaginal contraceptive barrier device, when used with either spermicidal or non-spermicidal lubricant. One-hundred-eighty-five (185) women enrolled at six centers. Half were randomized to use the device with spermicide and half with a non-spermicidal lubricant. To be eligible, volunteers had to be 18-40 years old (inclusive), in good health with regular menses, sexually active in an ongoing relationship and at risk for pregnancy, and willing to use Lea's Shield as their sole means of contraception for six months. Participants were seen at admission, one week, one month, three months and six months. Gross cumulative life table rates were calculated for pregnancy and others reasons for discontinuation. Adverse experiences and responses to an acceptability questionnaire were evaluated. One-hundred-eighty-two (182) volunteers contributed data to the analysis of safety and 146 to that of contraceptive efficacy. The unadjusted six-month life table pregnancy rate was 8.7 per 100 women for spermicide users and 12.9 for non-spermicide users (p = 0.287). After controlling for age, center, and frequent prior use of barrier methods, the adjusted six-month life table pregnancy rate was 5.6 for spermicide users and 9.3 for non-spermicide users (p = 0.086), indicating that use of spermicide lowered pregnancy rates, although not significantly, during typical use. For purposes of comparison, it is important to note that this study differed from the cap/diaphragm and sponge/ diaphragm studies in that a high percentage (84%) of volunteers were parous. For reasons that are unclear, pregnancy rates among parous women using barrier contraceptives tend to be higher than among nulliparous women. Indeed, in this study there were no pregnancies among nulliparous users of Lea's Shield. Standardization of parity of this study population on those of the cap/diaphragm and sponge/diaphragm studies suggests that unadjusted pregnancy rates for this device would have been considerably lower (2.2 and 2.9 per 100 users of spermicide and non-spermicide, respectively) had the study been done using the populations of earlier studies. Since no directly comparative study has been done, these figures provide a tentative estimate of the relative efficacy of Lea's Shield compared with the sponge, cap, and diaphragm. There were no serious adverse experiences attributed to the use of Lea's Shield. Acceptability was very good. Seventy-five percent (75%) of women responded to an end-of-study questionnaire; 87% of these reported that they would recommend Lea's Shield to a friend. Lea's Shield is a new vaginal contraceptive that does not require clinician fitting. Pregnancy rates in this study compare favorably with other studies of barrier contraceptive methods including the cervical cap, diaphragm, and sponge, even though this study was done with greater rigor and with a greater percentage of parous women than previous barrier studies. Lea's Shield appears to be safe and very acceptable to study volunteers.

Contraceptive efficacy and acceptability of the female condom

OBJECTIVES

The purpose of the study was to determine the contraceptive efficacy of the female condom and to provide data about the device to the US Food and Drug Administration.

METHODS

The clinical trial was conducted at six US sites and three sites in Latin America. Eligible subjects were in mutually monogamous relationships and agreed to use the female condom as their only means of contraception for 6 months.

RESULTS

A total of 328 subjects contributed to the analysis of contraceptive efficacy. Twenty-two US subjects and 17 Latin American subjects became pregnant, yielding 6-month gross cumulative accidental pregnancy rates of 12.4 and 22.2, respectively. During perfect (consistent and correct) use of the method, the 6-month accidental pregnancy rates were 2.6 and 9.5 for the US and Latin American centers, respectively. There were no serious adverse events related to the use of the method.

CONCLUSIONS

The female condom provides contraceptive efficacy in the same range as other barrier methods, particularly when used consistently and correctly, and has the added advantage of helping protect against sexually transmitted diseases.

Comparative contraceptive efficacy of the female condom and other barrier methods

Because the research design for the clinical trial establishing the contraceptive efficacy of the female condom--a six-month life-table probability of failure of 15% (12% in the United States vs. 22% in Latin America)--did not include randomization with another method of contraception, no definite conclusion about its comparative efficacy is possible. Comparisons using other female barrier methods as historical controls, however, provide evidence that, among women in the United States, the contraceptive efficacy of the female condom during typical use is not significantly different from that of the diaphragm, the sponge or the cervical cap. The six-month probability of failure during perfect use of the female condom is 2.6% among U.S. women, similar to rates for the diaphragm and the cervical cap but significantly lower than that for the sponge. Meaningful comparisons with the male condom are not possible because of the lack of data from carefully controlled prospective clinical trials. Extrapolations from the results on contraceptive efficacy suggest that perfect use of the female condom may reduce the annual risk of acquiring the human immunodeficiency virus by more than 90% among women who have intercourse twice weekly with an infected male.

Prevention of IUD-related pelvic infection: the efficacy of prophylactic doxycycline at IUD insertion

It is believed that much of the small increased risk for developing pelvic inflammatory disease (PID) associated with the use of an intrauterine device (IUD) appears to be caused by bacterial contamination of the endometrial cavity at the time of insertion. Previous research suggests that use of prophylactic antibiotics immediately prior to IUD insertion may reduce the risk of developing PID. This paper presents results from a randomized clinical trial of 1485 women in Ibadan, Nigeria evaluating the effectiveness of 200 mg of doxycycline (versus placebo) given orally at the time of IUD insertion in reducing the incidence of PID during the first three months of IUD use. Rate of PID infection in the doxycycline-treated group was not significantly lower than that in the placebo-treated group. The rate of unscheduled IUD-related visits to the clinic also was not significantly lower among the doxycycline-treated group. However, the incidence of PID was low (21 cases) for both study groups. Aseptic conditions during IUD insertion, follow-up visits with short intervals to monitor health, and treatment of opportunistic infections may have reduced the potential of PID within this population.