How long is the gestation period for a human?

  Improve

The gestation period of a human, from time of conception to birth is approximately 9 months (266 days/38 Weeks). 9.5 months is calculated from the first day of the last menstrual period (280 days/40 Weeks).
most full-term babies will come between 37-42 weeks

Correction: A pregnancy is considered to be "full-term" between 37 and 42 weeks.....therefore by definition, ALL full-term babies will come in that time frame. I think that's what that was meant to say. 40 weeks is still considered the standard length of a pregnancy and "due dates" are based on that number. However, newer studies have indictaed that the true AVERAGE gestation for a healthy pregnancy with spontaneous in a nulliparous (first-time) mother is approximately 41 weeks and 3 days, with multiparous (with previous children) mother giving birth spontaneously, on average, at 41 weeks and 1 day. But in America in particular, most labors are induced before reaching that gestation without medical cause, so they never reach the natural gestational "average".
Once a lady gets pregnant, it takes 9 months before the child comes into this world.
== Human Gestation Period == Forty (40) weeks is average. It is not uncommon for a fetus to be plenty developed by 38 weeks, or for a fetus to need up to 42 weeks to finish development.

The "normal" range is 38-42 weeks. The average is 40 weeks.

Many babies are born before the 38th week, and there no true medical emergencies. Others born before the 38th week have not completed development, particularly of the lungs.
The range is 37 to 42 weeks (259 to 294 days) depending on the person. The average is 40 weeks, anything less than 37 weeks is considered pre-term, which is dangerous due to underdevelopment. Over 42 weeks is also dangerous due to septic poisoning.

Months vs. Weeks

As any woman who has had a child (or has basic math and logic skills) can tell you, 40 weeks are 10 four week months, not 9! Depending on the time of year, they are usually 9 calendar months due to the extra days sprinkled in here and there in the Gregorian calendar, but weeks are a much simpler and more accurate way to determine where you are in your pregnancy and your due date.

First answer by Emdrgreg. Last edit by Keygirlus. Contributor trust: 0 [recommend contributorrecommended]. Question popularity: 57 [recommend question].