In general, any disease is most dangerous to a human society upon first exposure; within a few generations, natural selection encourages the survival of in­dividuals who have some natural resistance. When Europeans began colonial expansion in the 15th century, they brought new diseases (such as smallpox and measles) to the colonized lands; these diseases killed [...]

While advances in examining the fetus have been used to diagnose extremely severe defects, these same techniques have opened up possibilities for treating certain fetal disorders. The best-known example is treatment of hemolytic disease of the newborn due to Rh incompatibility.

Major developmental or genetic defects occur in more than one in 50 pregnancies. Some result in stillbirths; in others, the baby is born alive. Advances in prenatal diagnosis using the latest obstetrical instruments and equipments have made it possible to identify certain major defects early in pregnancy. For some cases in which the fetus has [...]

To maximize the chance of having a successful preg­nancy and a healthy baby, a couple should examine their health habits before pregnancy occurs. Both partners-but especially the woman-should eat a balanced diet and should avoid alcohol, tobacco, and all drugs except those taken in consultation with a physician. Women with metabolic disorders, such as diabetes [...]

Since the turn of the century, improvements in medi­cal care including the use of obstetrical instruments and techniques have resulted in a dramatic decline in infant and childhood mortality in developed countries. Cur­rently, infant mortality is more of a socioeconomic problem. The greatest difficulties are encountered with teenage pregnancies, which are associated with little or [...]