Fertility Control Agents Research Articles

Prostaglandins and Reproduction.

This is a review of the literature and a summary of the findings and the clinical studies dealing with the role of PGs (prostaglandins) in the general field of reproduction. The chemical structure of PGs, including the biosynthetic chain, is reviewed briefly. The role PGs play in normal menstruation and dysmenorrheic menstruation, normal pregnancy, labor induction, postconception fertility control, and induced abortion are reviewed, citing the studies involved. Most of the PGs inhibit spontaneous motility of the human myometrium, varying according to the phase of the menstrual cycle. PGs also have an effect on the fallopian tubes, the ovary, and male reproductive organs. PGs, especially PGF, have been identified in human amniotic fluid during spontaneous abortion and labor. In the future, PGs may be used as postconception fertility control agents, even self-administered agents. PGs could influence the process of reproduction by: 1) delaying ovum transport; 2) having an effect on the site of implantation; 3) acting as an abortifacient; and 4) through luteolytic action.

Contraception by intrauterine release of steroids

Due to the incidence of missed doses in a large population a failure rate of 4-7% for oral contraceptives has been reported. As a result a new group of pharmaceutical products has been developed. The most appropriate drug at the lowest effective concentration and with a minimum of patient intervention was sought. The compound developed by the ALZA Corporation was called Progestasert. It is a T-shaped device for uterine placement. Progesterone is contained within a capsule and released continuously at a rate of 65 mcg/day over a 1-year period. The polymer membrance control element achieves the precision and constancy of drug delivery. Clinical studies in 20 countries with 4200 women for 3600 woman-months of use have resulted in a failure rate of 1% and a continuation rate of 85% after 1 year of use. This method eliminates the need for estrogen and avoids systemic side effects. The total dose of progesterone released by the Progestasert during 1 year of use is less than the amount normally produced by the ovaries each day during the high point of the menstrual cycle. It is the 1st once-a-year hormone fertility control agent and the 1st target-specific hormonal system.

Directions and potentials of contraceptive research.

This article reviews the current status of birth control methods, emphasizing the reversible fertility control agents that will be needed during the next decade or two, notably in developing countries. Special mention is made of chemical approaches to abortion, hormonal agents, the intrauterine device, sterilization techniques, and male contraceptives. The prospects for reaching the goals of better research and more effective implementation are fairly dim unless major changes in public and governmental attitudes toward contraceptive research are instituted. Attention is drawn particularly to some of the operational problems associated with the development of new fertility control approaches in the female and in the male.

Fertility control agents as a possible solution to the world population problem.

While the demographic - the transition from high death rate and birth rate to low death rate and birth rate - occurred in the industrialized nations completion of the revolution with family planning methods alone may be implausible or too slow in arriving in the underdeveloped countries. Moreover even if couples throughout the world become proficient in family planning the world populations desire for children may prevent the avoidance of disaster. The author raises the possibility that in the future fertility control agents will be used by governments as supplements to family planning measures used voluntarily by couples. An example of a fertility control agent would be a compound raising the threshold requirement of some substance involved in the implantation of blastocysts. Such a compound may be available for field testing within 5-15 years. A fertility control agent must have less than 100% effectiveness and should reduce the fertility of everyone equally. Moreover it should be easily and unobtrusively a part of the intake of everyone in the population harmless inexpensive easily reversible unassociated with family planning of couples and unrelated to the sexual activity of individuals. Economic sanctions directed at couples bearing more than a predetermined number of children have been proposed but associated problems involve welfare of the children born in spite of the sanctions and discrimination against economic groups. Raising the legal age of marriage or denying requirements of married life (housing etc.) to people below a certain age are inconsistent with the more attractive concept of allowing marriage at an age consistent with cultural and biological desires. Policies allowing couples to have only a certain number of children might be unworkable unduely harsh or objectionable in method. When the population growth is seriously affecting the welfare of the population and voluntary means are inadequate then gover nmental action becomes morally and politically justifiable.