Prenatal development means the development since conception before birth. There are some factors that would influence prenatal development. Some of them are; maternal characteristics such as age (optimum 18-35 years), nutritional state, maternal illnesses thyroid hormone ,Maternal psychological state and maternal exposure to drugs and substances and smoking.
Mothers who have their first child when they are over 35 or under 15 are having experience more problems during pregnancy and difficulties during delivery than women between these ages. Apart from that Young adolescents are less likely to eat properly or to get prenatal care; older women are more likely to have diabetes, hypertension and other problems related to age of the mother. Some of maternal diseases and disorders can affect prenatal development such as Rh factor incompatibility high blood pressure; diabetes; rubella; and sexually transmitted diseases such as toxo-plasmosis, syphilis, gonorrhea, chlamydia, AIDS and genital herpes. The effects of maternal diseases are related to the stage of fetal development during which they are contracted, and the length of time that they last. For example, doctors discovered that when a mother contracts rubella early in her pregnancy her child might suffer blindness, heart abnormalities and brain damage as a result.
Deficiencies in maternal diet are related to increased rates of premature, stillbirth, infant mortality, physical and neural defects, and small size. Also maternal emotional disturbance has been related to complications during pregnancy and delivery and to hyperactivity and irritability in infants after birth.
Mothers who smoke cigarettes or drink alcohol and having psychoactive drugs are more likely to bear premature or low-birth weight babies. In addition, maternal drinking is related to fetal alcohol syndrome which results in facial abnormalities short stature and mental retardation. Apart from that some obstetrical medications used to ease pain and sedate women during labor and delivery may affect the newborn’s behavior for several days after birth. The specific time of when the growing organism is exposed to the danger can play a major effect in the ultimate outcome. For example an embryo is most vulnerable to tera-togens in the first eight weeks after conception. However, damage to major areas of the body including the brain and eyes can also occur during the later weeks of pregnancy.