The first stage of pregnancy is obviously the fertilization of the egg. This takes place in the woman’s fallopian tube and then the fertilized egg moves to the uterus three or four days after fertilization. During this stage of pregnancy, the fertilized egg is referred to as a zygote. The zygote implants itself in the lining of the uterus which is the stage of pregnancy that the zygote becomes an embryo. The embryo now divides into two parts which will become the placenta and the baby.
The next important stage of pregnancy occurs during the sixth week where the baby’s heart will begin to beat and blood will start to circulate throughout his body. The umbilical cord will also start to form at this stage of pregnancy as will his head, eyes, intestines, and liver. The embryo then moves onto the next major stage of pregnancy during the 10th week when it becomes a fetus. At this stage of pregnancy, the baby’s external genitalia begin to form and her facial features, as well as limbs, become more perceptible. By the end of this stage of pregnancy, the baby’s vital organs will not only be formed but will also have begun to work.
The second-trimester stage of pregnancy begins after the 14th week. Once a woman reached this stage of pregnancy the risk of miscarriage is significantly reduced. The baby’s reproductive organs are developing and it will also begin to grow some hair as well as from eyelids, fingernails, and toenails. This is the earliest stage of pregnancy that a woman may begin to feel some of the baby’s movement, especially if is not her first pregnancy.
Week 18 is the next milestone stage of pregnancy because the bones in the baby’s inner ear will have developed enough that he may start responding to loud outside sounds. During week 22 the baby’s brain is developing and ultrasound images begin to show the baby moving her limbs more.
Week 26 is an important stage of pregnancy as it marks the point where the third trimester begins and a baby born at this point would actually have a good chance of survival. During week 30 the baby begins to try to breathe. Obviously, she is still surrounded by amniotic fluid and her gulping may give her hiccups.
The final stage of pregnancy is reached at 40 weeks. By this stage, the baby has fully developed and could be born at any time. It is not unusual for this stage of pregnancy to actually go on for up to two weeks past the estimated due date.