Prenatal development is the period in development from conception to the onset of Perinatal period is the period beginning about the seventh month of pregnancyand continuing until about four weeks after birth. Postnatal development is the periodin development the follows directly after birth. The germinal stage is the stage lastingabout ten -fourteen days following conception before the fertilized egg becomesimplanted in the uterine wall. The embryonic stage is the stage in which majorbiological organs and systems form. The fetal stage is the stage in which is marked byrapid growth and preparation of body systems for functioning in the postnatalenvironment. Viability is the ability of the baby to survive outside the mother’s womb.The gestational age is the age of the fetus derived from onset of mother’s lastmenstrual period. The number of older mothers is on the rise in the U.S. as womenpostpone pregnancy to establish careers or for other reasons. Healthy women olderthan thirty-five routinely deliver healthy infants just as other between the ages oftwenty and thirty-five do. Teenagers, however, may be at a greater risk for deliveringless healthy babies. Lack of prenatal care is a big reason. Diets, while pregnant, mustbe sufficient not only in number of calories but also with respect to the right amount ofproteins, vitamins, and other nutrients. Stress also plays a big role in delivering ahealthy baby. Cultural beliefs about potentially harmful consequences of frightening or stressfulevents on fetal development are pervasive, and many societies encourage a calmatmosphere for pregnant women. The social support a pregnant woman receives fromfamily and friends is an important factor that can lessen the consequences of stressduring pregnancy.Another reason is the complicated nutritional needs of teenagers. Teenage mothersgive birth to as many as 500,000 babies in the U.S. every year. It is suggested towomen that are thirty-fiv...