Dichorionic-Diamniotic Twins (DCDA)
Definition - What does Dichorionic-Diamniotic Twins (DCDA) mean?
Dichorionic-diamniotic (DCDA) is a twin pregnancy where each fetus has its own placenta and amniotic sac. This means that each embryo has its own individual chorion (the outer membrane that develops into the placenta) and amnion (the inner membrane that fills with amniotic fluid and becomes the amniotic sac).
DCDA twins most frequently occur when two eggs are fertilized by two sperm simultaneously (dizygotic twins), but may also be caused by a single zygote splitting into two (monozygotic twins).
Assisted reproductive technologies (ART) greatly increase the chance of becoming pregnant with twins.
Of all twin pregnancies, DCDA twins have the lowest rate of complications.
FertilitySmarts explains Dichorionic-Diamniotic Twins (DCDA)
Dizygotic DCDA twins
In order for dizygotic DCDA twins to develop, two eggs must be present for fertilization. While this does occur naturally, it is rare. However, this type of pregnancy is common with fertility treatments such as intrauterine insemination (IUI) or in vitro fertilization (IVF) when multiple eggs are either present (in the case of IUI) or fertilized and transferred to the uterus as embryos (in the case of IVF).
Multiple gestation pregnancies of two or more fetuses are a common result of both of these treatments.
Monozygotic DCDA twins
In order for monozygotic DCDA twins to develop, one fertilized egg, called a zygote, splits into two separate entities in the 1-4 days following fertilization. This treatment also occurs naturally and may be impacted by other variations of ART. However, it is a rarer occurrence, particularly with DCDA twins.
Complications with DCDA twins
While all twins carry a higher level of risk then a singleton pregnancy, DCDA twins are considered a lower risk multiples pregnancy. Because each fetus is contained in its own sac, there is a reduced chance of entanglement or cross-contamination.
However, the person pregnant with DCDA twins still faces additional pregnancy complications, including preeclampsia, gestational diabetes, or anemia.
- Dichorionic diamniotic twin pregnancy. (2019).
- Antenatal care with twins -Your pregnancy and baby guide. (2019).