A common way to look at prenatal development is to divide it into three categories. Germinal period, embryonic period, and fetal period. The germinal period is the first two weeks of prenatal development consisting of the blastocyst. The blastocyst has to embed itself into the uterine wall during this time. Weeks three to eight are the embryonic period. This is when the embryo forms and the neural tube, head, and a small blood vessel that takes the form of a beating heart develop. Arms, legs, eyes, ears, nose, and mouth also start to form. The last period is the fetal period. It goes from nine weeks until birth. This is an important time when major development occurs and also the sex is formed.
The age of liability is important during the fetal period. It simply is the time from which the baby can survive on it's own. This time is about 22 weeks. Any baby born before then will not survive because the brain has not yet developed the ability to survive.
Teratogens can be very dangerous to the development of a prenatal baby. Teratogens are pollutants that can cause physical and neurological damage. Some examples would be, drugs, smoking, drinking, too many vitamins, prescription drugs, and viruses. To reduce this risk, it is important to never be around any of the chemicals listed above and always consult with your doctor before taking prescription drugs. Some are safe to take, while others can be very harmful. It also can depend on at what point in development the fetus is in.
All in all, giving birth is a blessing and it should not be considered as risky if all the precautions are met and you give birth with doctors present. Always make sure to stay away from possible teratogens that will cause birth defect and personality disorders. Take preventive measures from STD's as they are also considered as teratogens. Refer back to the stages of development and then ask your doctor what prescription drugs will not affect the baby's development in that stage. With all that said, you should give birth to a healthy, happy baby.