Ovarian and oocyte targets for development of female contraceptives.

INTRODUCTION: Steroid hormone-based contraceptives have been used by women for long time since their introduction. Efforts have been made to make steroidal contraceptives cost-effective, safe and improve their users' compliance. In addition, attempts have been made to develop nonsteroidal contraceptives. Contraceptive vaccines have been investigated as an alternate strategy for contraception. AREAS COVERED: The currently used steroidal contraceptives are reviewed. In addition, status of emerging nonsteroidal contraceptives that inhibit folliculogenesis, oocyte maturation, ovulation and endometrium receptivity targeting phosphodiesterase 3, angiopoietins, gonadotropin-releasing hormone, COX-2, progesterone/estrogen receptor and follicle-stimulating hormone receptor are presented. Various approaches to develop contraceptive vaccines aiming to inhibit ovarian follicle development, ovulation, fertilization and implantation including their current applications and limitations are discussed. EXPERT OPINION: Development of new nonsteroidal contraceptives, in addition to long-acting steroidal contraceptives, is pertinent for offering wider choice to women. It is imperative that basic research to discover new targets in the ovaries must be undertaken to facilitate development of novel contraceptives. Further, efforts on studying the feasibility and safety of contraceptive vaccines may be continued to bring these within the realm of application as contraceptives for humans.