New types of diaphragms and cervical caps versus older types of diaphragms and different gels for contraception: a systematic review.

Introduction: Our primary objective was to evaluate whether new types of single-size diaphragms or cervical caps differ in prevention of pregnancy compared with older types of diaphragms, and whether different types of gels differ in their ability to prevent pregnancy. A secondary aim was to evaluate method discontinuation and complications.

Methods: A comprehensive search was conducted in PubMed, Embase and the Cochrane Library. The certainty of evidence was assessed according to the GRADE system.

Results: Four randomised controlled studies were included in the assessment. When comparing the new and old types of female barrier contraceptives the 6-month pregnancy rate varied between 11%-15% and 8%-12%, respectively. More women reported inability to insert or remove the FemCap device (1.1%) compared with the Ortho All-Flex diaphragm (0%) (p<0.0306). Urinary tract infections were lower when using the single-size Caya, a difference of -6.4% (95% CI -8.9 to -4.09) compared with the Ortho All-Flex diaphragm. The 6-month pregnancy rate for acid-buffering gel and spermicidal nonoxynol-9 gel varied between 10% and 12%. The discontinuation rate was lower in women who used acid-buffering gel compared with nonoxynol-9 gel (risk ratio (RR) 0.77, 95% CI 0.68 to 0.97).

Conclusions: Pregnancy rates were generally high in women using female barrier contraceptives. There was no difference in the efficacy for pregnancy prevention between the new types of diaphragms and cervical caps and the older diaphragms. The new types of diaphragms and cervical caps resulted in fewer urinary tract infections. Acid-buffering gels did not differ from spermicidal nonoxynol-9 gels regarding pregnancies but seemed to be better tolerated.