Spermicides can be purchased without a physician's prescription in supermarkets and pharmacies. They can be used alone but are often used in conjunction with a vaginal barrier method (diaphragm, sponge, or cap). Nonoxynol-9 (N-9), the most commonly used spermicide, is an agent that destroys the sperm cell membrane, thereby immobilizing sperm. But, recent studies have shown that N-9 does not protect against STIs and HIV (152). Spermicidal formulations include gels, creams, suppositories, film and male condoms. Pregnancy rates among typical users range from 5% to 30% in the first year of use (7). Methodology in determining these rates has not been consistent leading to skepticism of much of the data. Like the barrier methods, the effectiveness of spermicides is dependent on their consistent and correct use. Its advantages are similar to barrier methods of contraception.

There is a consensus for the need to increase efforts to find innovative approaches to expand the focus of family planning methods beyond simple contraception to include the concern for reproductive health. Efforts to combine effective contraception and protection against HIV and STI transmission are of the utmost priority because the incidence of transmission of HIV and STIs is greatest in women of reproductive age (153).

Any substance that can substantially reduce the transmission of HIV and STI when applied to the vagina is considered a microbicide. Many other compounds are currently under development. These formulations will probably be used as an adjunct to condoms, but may be used as primary protection for those who are unable or unwilling to use condoms consistently. These microbicides will work by either killing or immobilizing pathogens possibly by forming a barrier between pathogen and vaginal tissues, preventing the infection from entering target cells, preventing a pathogen from replicating once it has entered cells, by boosting the vagina's or rectum's own defense system or by acting like invisible condoms. The most desirable qualities of a new formula microbicide would be that it is applicable hours before sexual intercourse, it is not messy or "leaky," and spreads rapidly and evenly over the vagina and cervix (79).

Currently it is estimated that more than 60 potential microbicides are in various phases of development. The class of new compounds can generally be stratified by their mechanism of action (154). The first generations of microbicides, which work on a charge basis as polyanionic molecules, are about entering Phase 3 clinical trials. However, many of these compounds are still in pre-clinical work. These drugs have previously been used in therapeutics, and are now crossing over. Anti-retroviral compounds, like tenovafir, have been formulated as a microbicide. Some of the newer NNRTIs are also being developed as microbicides. They are effective against herpes simplex, bacteria, yeast, fungi, viruses, and potentially effective against other STIs as well.

Surface Active Agents are compounds that penetrate cervical mucus readily, disrupt viral envelopes and cover the surface of viral STIs. Compounds such as nonoxynol 9, octoxynol 9, benzalkonium chloride, menfegol and N-docosanol are included in this category. Examples include C31G (Savvy Biosyn Inc), which is a mixture of two synthetic amphoteric surface-molecules (alkyl amine oxide and alkyl betaine). It has a broad spectrum of antimicrobicidal activity including activity against bacteria, yeast, fungi, and viruses (HIV,HSV, and HPV). Another example is Benzalkonium Chloride (BZK), (Axcan Ltd. Protecaid ®). It is active against a broad spectrum of pathogens including HIV, chlamydia, and gonorrhea.

Sulfated Compounds are highly negatively charged. These compounds bind to virus or host cell receptors, thus blocking viral uptake; however they do not kill the virus. Examples include Dextrin Sulfate, Dextran 2 sulfate, Carageenan, Polystyrene Sulfonate, Heparin Sulfate: Cholic Acid, Cellulose Sulfate, PC-515, and Naphthalene Sulfonate (PRO 2000).

Anti-HIV Compounds are antiretroviral agents and prevent virus replication. Products such as X-2371 (Low-molecular-weight, non-peptide oligospecific integrin modulator, PMPA (Adenine Anti-retroviral Drug), Serine Proteinase Inhibitor, Novel Aryl Phosphate Derivatives of AZT, nevirapine gel/cream, and cyanovirn N (selectively inhibits binding of HIV molecule to receptor) are all also under development as topical microbicides.

Some compounds may increase the host natural defenses against certain sexually transmitted pathogens by maintaining the normal acidic pH of the vagina in the presence of semen. They contain lactobacillus which naturally resides in the human vagina and produces hydrogen peroxide to kill HIV and STDs. Examples are: Lactobacillus suppositories, Buffer gel, and Acid gel (ACIDFORM).

Invisible Condoms: Thermoreversible Gel - Prevents infection by forming a protective barrier after being inserted into the vagina or rectum. It is a liquid at room temperature and quickly turns into an impermeable gel inside the rectal/vaginal canal.

Abstinence: Couples who avoid sexual intercourse are practicing abstinence. Effectiveness for preventing pregnancy is 100%, but HIV and STIs may spread through the oral or rectal mucus membrane.

Coitus Interruptus: Also known as the withdrawal method, coitus interruptus entails withdrawal of the penis from the vagina (and external genitalia) immediately prior to ejaculation. Effectiveness depends largely on the man's ability to withdraw prior to ejaculation. Its actual efficacy is difficult to measure but the probability of pregnancy among perfect users is estimated to be approximately 4% in the initial year of use. (155)

Fertility Awareness: Symptothermic method -Natural family planning methods use the signs, symptoms, and timing of a normal menstrual cycle to avoid intercourse during fertile intervals. These methods are effective because of periodic abstinence during the fertile period of a woman's menstrual cycle. The fertile period of a woman's menstrual cycle can be determined by using cycle beads, a calendar, measuring basal body temperature and monitoring cervical secretions. (156)

Calendar Method: Estimating the fertile period during each menstrual cycle is based on 3 assumptions: (1) ovulation occurs on day 14 (±2 days) before the onset of the next menstrual flow, (2) the ovum survives for approximately 24 hours, and (3) sperm remain viable up to 5 days. Past cycle lengths give an estimate of fertile days within a given cycle. Avoidance of pregnancy is achieved by abstinence beginning about 5 days before and ending nearly 5 days after ovulation.

Basal Body Temperature: Most ovulatory cycles demonstrate a biphasic temperature pattern with lower temperatures in the first half of the cycle and higher temperatures beginning at the time of ovulation and continuing for the remainder of the cycle. Because this method does not adequately predict ovulation in advance, couples are instructed to abstain from intercourse or use a barrier method of contraception for the first half of the menstrual cycle until at least 2 days after a rise in temperature signifying ovulation.

Cervical Secretions: Changes in the character of cervical mucus can signify the fertile period of a woman's menstrual cycle. Cervical mucus that is abundant, clear or white, stretchy, and slippery represents the fertile period. Ovulation most likely occurs within 1 day of the appearance of cervical mucus that is abundant, stretchy and slippery. After ovulation, cervical secretions appear thick, cloudy and sticky. Couples are counseled to avoid intercourse when cervical secretions are first noted until 4 days after the peak of clear and slippery cervical mucus.

Couples can also use a combination of natural family planning methods (i.e., basal body temperature measurements and cervical secretion monitoring) to further avoid an undesired pregnancy. In addition, recent advances in home hormonal detection kits allow for detection of ovulation and better timing of abstinence for avoidance of pregnancy.

Lactation Amenorrhea Method (LAM) - Breastfeeding: Breastfeeding provides more than 98% protection from pregnancy in the first 6 months after birth (157) This method of contraception requires complete or nearly complete infant dependence on breast milk so that frequent suckling (at least 6-10 times per day) prevents ovulation. High frequency of feeds, long duration of each feed, night feeds, and short intervals between breastfeeds delay the return of ovulation. (158, 159) Infant suckling disrupts the pulsatile release of gonadotropin releasing hormone (GnRH) by the hypothalamus resulting in abnormal pulsatility of LH and subsequent anovulation (160). Ovulation however can occur even in the absence of menstruation. The probability of ovulation occurring before menstruation increases with time after delivery; the probability that women will ovulate before the resumption of menses increases from 33-45% during the first 3 months after delivery to 87-100% more than 12 months from delivery (161). To maintain effective contraception, another method should be used as soon as menstruation resumes, the frequency or duration of breastfeeding is reduced, food (or bottle) supplements are introduced, or the duration since delivery is 6 months. This method provides no protection against sexually transmitted diseases, but may help reduce post partum bleeding.