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

Contraception. 1996 Jun;53(6):329-35. doi: 10.1016/0010-7824(96)00081-9.

Abstract

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.

PIP: At six US centers, between August 1991 and October 1993, a prospective, double-blind, randomized clinical trial was conducted to evaluate the contraceptive efficacy of Lea's Shield (a new vaginal contraceptive barrier device) used with and without a spermicidal lubricant as well as its safety and acceptability. The clinical researchers enrolled 185 healthy women aged 18-40 who menstruated regularly, were sexually active, and at risk for pregnancy. 84% of the women were parous. They were asked to use Lea's Shield as their only contraceptive method for 6 months. The analysis of safety included 182 women, while that of contraceptive efficacy included 146 women. The adjusted 6-month life table pregnancy rate for spermicide users was lower than that for non-spermicide users (5.6% vs. 9.3%), but not significantly so (p = 0.086). None of the nulliparous women conceived, however. When the researchers standardized parity in this study population comparable to the parity of cap/diaphragm and sponge/diaphragm studies, the unadjusted and adjusted pregnancy rates would have been much lower (2.2% for spermicide users vs. 2.9% for non-spermicide users and 1.3% vs. 2.6%, respectively). No woman experienced serious or unexpected adverse effects using Lea's Shield. Discontinuation rates for device-related reasons were low (7.8% for spermicide users and 6.7% for non-spermicide users). 87% of women who completed an end-of-study questionnaire and 69% of men would recommend Lea's Shield to a friend. 84% of women and 55% of their partners liked Lea's Shield. 84% of women who had an opinion on the diaphragm preferred Lea's Shield. The aspects most liked were convenience and ease of insertion. These findings suggest that this new vaginal barrier contraceptive (available in one size fits all) has a relatively good contraceptive efficacy compared with other barrier methods and is safe and acceptable.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase II
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Contraceptive Devices, Female / standards*
  • Contraceptive Devices, Female / statistics & numerical data
  • Double-Blind Method
  • Educational Status
  • Female
  • Follow-Up Studies
  • Humans
  • Lubrication
  • Marital Status
  • Parity
  • Patient Compliance
  • Patient Satisfaction
  • Patient Selection
  • Pregnancy
  • Pregnancy Rate
  • Prospective Studies
  • Safety
  • Spermatocidal Agents / administration & dosage*
  • Surveys and Questionnaires
  • Treatment Outcome

Substances

  • Spermatocidal Agents