Fetal environment
Amniotic fluid
The amniotic fluid surrounding your baby is essential to their growth and development. Among other things, it:
- Keeps your baby at the right temperature.
- Protects your baby against shocks from outside the womb.
- Provides space for your baby to move and develop their muscles and lungs.
The fluid is contained in a kind of pouch that surrounds the baby (the amniotic sac or membrane). The membrane actually consists of two layers, which is why you will often hear it referred to as “the membranes.”
Just before or during labour, the sac will break, causing the amniotic fluid to leak out. This is what’s known as “breaking the water.”
Placenta and umbilical cord
The placenta starts to grow as soon as the fertilized egg embeds itself in the uterus. It is connected to the baby by the umbilical cord.
At four weeks of pregnancy, blood begins to flow between you and the embryo.
The umbilical cord and placenta carry the oxygen and nutrients your baby needs to grow. They also help get rid of your baby’s waste by returning it to your body, which then eliminates it.
The placenta secretes hormones into your blood that maintain the pregnancy and help the fetus grow. It also acts as a barrier between your blood and the blood of the fetus.
But the placenta does not filter everything. Certain substances that are harmful to the fetus can get through, including alcohol, certain drugs, and certain medications.