Final answer:
The most serious problem with monochorionic placentas is Twin-twin transfusion syndrome (TTTS), which occurs when there is uneven blood flow between the twins sharing the same placenta. This can result in serious complications for both twins.
Step-by-step explanation:
Most Serious Problem with Monochorionic Placentas
The most serious problem with monochorionic placentas is
Twin-twin transfusion syndrome (TTTS)
. TTTS occurs when there is uneven blood flow between the twins sharing the same placenta, leading to one twin receiving too much blood and the other not enough. This can result in serious complications for both twins, including organ damage and even death.
Other problems such as cord entanglement, preterm labor, and placental abruption can also occur in monochorionic pregnancies, but TTTS is considered the most severe.