The fetal life support system consists of the placenta, umbilical cord and amniotic sac filled with amniotic fluid. This life support system helps the baby develop in the uterus.
 

Components of the fetal life support system

The placenta

This organ is attached to the inside of the  uterus and connects to the fetus by the umbilical cord.  The placenta produces pregnancy related hormones such as chorionic gonadotropin (hCG), estrogen, and progesterone. The placenta is expelled from the uterus in a process known as the after birth.

What does it do : Small blood vessels carrying fetal blood runs through the placenta which is made of the blood of the mother. Oxygen and nutrients  are transferred from the mother across the placenta to the fetus and  waste products are transferred from the fetal blood to the maternal  blood  without the two bloods mixing up.

The umbilical cord

 
This is the life line that attaches the placenta to the fetus. It can grow as long as 60cm allowing the baby enough cord to move around without causing any damage to the cord or placenta. The cord is cut after delivery of the baby. The remaining section will heal and form the baby’s belly button. The umbilical cord  may form a knot  or wrap around part of the baby’s body during pregnancy. This is common and cannot be prevented. It does not pose any harm to the the fetus.

What does it do : The umbilical cord is made up of 3 blood vessels.The  2 small arteries carry blood to the placenta. The larger vein returns blood to the fetus.

The amniotic sac

 
This sac is filled with the amniotic fluid. Around pregnancy week 10, there is about 30 ml of this  fluid present. The fluid reaches its peak around 34 to 36 weeks at which time it is around 1 liter. When your water breaks, it is the amniotic sac that raptures  causing the amniotic fluid to leave the body. When this happens , your baby will still be supported  by the umbilical cord . It also means  your baby will be arriving soon.

What does it do : It gives the baby enough room to swim and move around to help build muscle tone. The temperature of the  amniotic sac and fluid is slightly higher than that of the mother. It is usually 99.7 F.  This helps keep the baby cozy.

Fetal life support system in multiple pregnancy

 
Identical twins often share the same placenta. However they usually have a separate amniotic sac and always have their own umbilical cord. Non identical twins have separate placentas, amniotic sacs and umbilical cords.