PRENATAL DEVELOPMENT The prenatal development is sometimes separated into 3 development periods.

Period of the zygote Lasts for about 2 weeks Fertilized egg reaches and attaches itself to the lining of the uterus. Size of a pinhead.

Period of the embryo Second stage Lasts from the 3rd week until the 8th week. At 3 weeks after conception, the heart is the largest organ, and it has already started beating.

Placenta The placenta (which attaches the sacs around the embryo to the uterus) and the umbilical cord (the tube that connects the placenta to the embryo) develop.

Umbilical cord The umbilical cord carries nourishment and oxygen from the mother’s blood stream to the baby’s and takes wastes from the baby.

The growing embryo is surrounded by a bag of liquid called amniotic fluid. It acts as a cushion to protect the embryo.

During this time all the major organs are formed.

Period of the fetus Begins around the 8th or 9th week and lasts until birth. By the beginning of this period, the embryo has developed the beginnings of all organs and body parts. It is recognizable as a human being. Facial features are forming and all the internal organs are present, but not ready to function yet.

During the 4th or 5th month the mother begins to feel some kicks and movement of the baby. This is known as quickening.

By the 7th month the fetus is capable of living outside the womb, but not without a lot of medical help. From the 7th month on the fetus’s main task is to get ready for independent life. It will gain weight rapidly, fat deposits develop under the skin to help maintain body heat after birth.

The final weeks of pregnancy, the fetus stores nutrients and builds immunities to disease and infection. The fetus can do many things at this point. It sucks it’s thumb, coughs, yawns, kicks, hiccups, and even cries.

During the 9th month the baby’s weight seems to shift down and the mother feels more comfortable. This is called lightening. The baby has moved head first (usually) into the birth canal to prepare for birth. After about 40 weeks the time has come for the baby to be born.