What is a multiple pregnancy?
A multiple pregnancy occurs when more than one baby develops in the uterus. This happens when two or more eggs are fertilized. It can also result from the division of a single fertilized egg (identical twins).
What are the types of multiple pregnancies?
Multiple pregnancies are defined based on the number of placentas (chorion) and the number of amniotic sacs (amnion).
The most common ones are:
• Dichorionic diamniotic gestation : This is the most common type of multiple gestation, representing 70-80% of cases. It consists of two placentas and two amniotic sacs, one for each fetus. They can be of the same sex or different sexes .
• Monochorionic diamniotic pregnancy : This is the second most common type of multiple pregnancy, representing 20-30% of cases. It consists of a single placenta and two amniotic sacs: each fetus has its own sac, but they share the placenta. They are identical twins of the same sex.
• Monochorionic monoamniotic pregnancy: This is very rare, representing 1% of multiple pregnancies. It consists of a single placenta and a single amniotic sac, which contains both fetuses. They are identical twins of the same sex .
• Triplet gestation : is very rare. They can consist of one, two or three placentas and two or three amniotic sacs. They can be of the same sex or different sexes
