Clannad - Season 2 Episode 16 White Darkness

Winter comes and Nagisa enters the final months of her pregnancy, but she becomes sick again. On a snowy day, Nagisa goes into labor two weeks early and her family, unable to transport her to a hospital in time, is forced to have her give birth at home. After an excruciating process, Nagisa successfully gives birth to her daughter, Ushio, but the delivery and her illness combined take their toll on her and Nagisa dies moments after seeing her newborn baby. Tomoya, who has stayed by her side for the entire time, does not take the sudden turn of events well. His dream of raising their daughter together as a family is shattered.