A state of a female carrying a fertilized egg in her womb until gestation and a child is born. This entire process takes roughly nine months, and is broken into three-month periods known as trimesters.
During the first trimester, some of the most dramatic changes happen as well as physical illnesses and aches. The fetus grows largely in this stage, and starting to develop specific tissues to develop organs. Cramps for the mother are also very common during this stage. "Morning sickness" is also common, but usually improves after the first trimester. By the end of the eighth week in the twelve-week period, all the fetus's major organs, legs, arms, genitals, and toes are all roughly formed before entering the second trimester. On average, the fetus is about three inches long and weighs about one ounce. The women may start to notice certain foods that she likes and she may crave them, this is just because they need that certain nutrient.
During this time the mother usually feels more energetic, and morning sickness usually fades. By now most mothers are capable of seeing the sex of the baby or not, however some choose not too. At this point the mother also begins to gain weight, and lots of it. Her uterus can expand to become twenty times bigger than its normal size. This is when the mother starts to feel the fetus move inside her, though it can be much later until this happens in some cases. Breast milk production begins when specific hormones are produced by the female's body as they approach the Third Trimester.
The fetus finishes up developing within the uterus and the female's body begins to prepare itself for the eventual birthing of the child. The mother begins experiencing varying contractions in her hip region in the third trimester, since the vagina is getting prepared to become the birth canal in which the baby is delivered from the uterus down to the vaginal opening. Changes with the body keep occurring until the mother enters labor in the late stages of the Third Trimester and in most cases she can successfully deliver her new child into the world.
Pregnancy has been and is still featured in many of the various anime and manga franchises that have been released over the years.
In certain Hentai-themed anime or manga franchises, the pregnancy of the main female character or of several female characters within that series usually occurs due to the unprotected sex featured within the anime/manga in question. Some series deal with it in a appropriate and respectful mannor, but there are other series that decide to use it as a way to "spice" up their stories by having the pregnant female characters engage in sex.