Which is the most common cause of discordant growth in dichorionic gestations?

Which is the most common cause of discordant growth in dichorionic gestations?

• A. IUGR
• B. TTTS
• C. Selective fetal growth restriction
• D. Placental insufficiency

Answer: (A)

Discordant growth in a dichorionic twin pregnancy most often comes from one fetus experiencing intrauterine growth restriction. Because each twin has its own placenta, problems that specifically restrict growth tend to affect only one pregnancy partner, leading to a size difference between the twins. TTTS requires shared placental circulation and occurs in monochorionic gestations, so it’s not the common cause in dichorionic twins. Selective fetal growth restriction is a term heavily tied to placental sharing and vascular connections in monochorionic placentation, making it less typical here. Placental insufficiency can underlie IUGR, but the overall and most frequent presentation is IUGR of a single twin, giving rise to discordant growth between the two.

Discordant growth in a dichorionic twin pregnancy most often comes from one fetus experiencing intrauterine growth restriction. Because each twin has its own placenta, problems that specifically restrict growth tend to affect only one pregnancy partner, leading to a size difference between the twins. TTTS requires shared placental circulation and occurs in monochorionic gestations, so it’s not the common cause in dichorionic twins. Selective fetal growth restriction is a term heavily tied to placental sharing and vascular connections in monochorionic placentation, making it less typical here. Placental insufficiency can underlie IUGR, but the overall and most frequent presentation is IUGR of a single twin, giving rise to discordant growth between the two.