Fetching details from the dictionary...
multiple pregnancy; multiple conception; multiple birth
双子や三つ子は多胎の一種だ。
Twins and triplets are a type of multiple birth.
体外受精では多胎になる確率がやや高い。
The chance of a multiple pregnancy is somewhat higher with IVF.
多胎妊娠はリスクが高いため、専門的な管理が必要だ。
Multiple pregnancies carry higher risks and require specialized care.