placenta: Quick Facts

Written and fact-checked by

The Information Architects of Encyclopaedia Britannica

Last updated

Nov. 8, 2026

News •

Scientists discover a surprising clue to autism's origins hidden in the placenta • Nov. 3, 2026, 7:53 AM ET (Science Daily)

Videos

Close-up illustration of a human fetus inside the womb, showing the developing baby holding the umbilical cord in a warm, reddish environment.

See All Videos →

Topics

nondeciduate placenta placental barrier syndesmochorial placenta chorionic placenta yolk-sac placenta deciduate placenta epitheliochorial placenta chorioallantoic placenta afterbirth chorion

Dig Deeper: More Articles That Discuss This Topic

pregnancy: Diseases of the placenta