Xtro  (1983)
 [Type: Rapid Alien Pregnancy, Belly Expansion]

Xtro is an infamous pregnancy/belly inflation movie, simply for its scene that occurs early in the movie in which a woman is impregnated by an alien. She then proceeds to hold her stomach as it suddenly swells up. She gets bigger onscreen while wearing a robe.  After crashing around her kitchen she falls to the floor and her bare belly becomes exposed.  There is movement in the belly, which is enormous at this point, but she then gorily gives birth to a full grown man. Its a fun, but too-short scene, and unfortunately the alien impregnation doesn't occur again in the movie. 

Rating:
8/10