There are actually quite a few films for this in the history of Japanese cinema, so many in fact that Chika Kinoshita at the University of Western Ontario is writing a piece on the pregnancy films of Japan. You should look her up.
Of these, the most fascinating and impressive (and also autobiographical) are by Kawase Naomi. Many of her films fit precisely what you are interested in. Her first films are about the aunt who played surrogate mother to her. In one of her feature films she seems to stage her own desire for giving birth, and when she finally manages it in real life she films it. They are wonderful, beautiful, touching films. Here is the box set of her documentaries; the features are easier to get. She also has a nice blog that interweaves with the documentary films in curious ways (link below---the English is a rough translation of what she's writing in Japanese).
http://www.yesasia.com/us/naomi-kawase-documentary-dvd-box-dvd-japan-version/1010714594-0-0-0-en/info.htmlhttp://www.kawasenaomi.com/en/diary/
Cheers,
Markus
----
Online resources for film/TV studies may be found at ScreenSite
http://www.ScreenSite.org
