dichorionic diamniotic
Type of twin pregnancy where each fetus has its own separate placenta and amniotic sac.
Full Definition
Dichorionic diamniotic (DCDA) twins represent the safest type of twin pregnancy, where each fetus develops with its own placenta (chorion) and amniotic sac (amnion). This configuration occurs in all dizygotic (fraternal) twins and approximately one-third of monozygotic (identical) twins, depending on the timing of embryonic splitting. DCDA twins have the lowest risk of complications compared to other twin types, as there are no vascular connections between the fetuses. However, they still carry increased risks compared to singleton pregnancies, including preterm birth, growth restriction, and pregnancy-induced hypertension. Chorionicity determination is crucial and is best accomplished in the first trimester using the lambda or twin peak sign on ultrasound.
Usage
Usage note: Often abbreviated as DCDA; chorionicity determination is critical for risk assessment.
In Context
- "The first-trimester ultrasound confirmed dichorionic diamniotic twinning with a clear lambda sign." — Ultrasound report
- "Dichorionic diamniotic twins have a lower risk of complications than monochorionic pregnancies." — Patient education material