"Ever notice how many films portray pregnancy as infestation, as colonization by stealth? Rosemary's Baby was just the beginning. In Alien, a foul extraterrestrial claws its way out of John Hurt's belly. In Mimic, a woman gives birth to a two-foot maggot. Later, the X-files turned bug-eyed aliens bursting gorily from human mid-sections into a running theme. In horror and sci-fi, the host is consumed or rent, reduced to husk or residue so that some nightmare creature may survive its shell."
from We Have to Talk About Kevin