Due Date - Pregnancy Calendar Due Date

After the moment you find out you're pregnant, the next thing on many women's minds is their estimated due date. The typical full term pregnancy is nine months or 40 weeks or 280 days, give or take a few weeks. To calculate your due date you begin your day count from your last period, not the conception date (or the date you suspect you conceived).

How to Get a Pregnancy Calendar Due Date Calculation

Many women use a due date calculator or due date predictor to complete the calculations for them. There are a variety of online pregnancy calendars that allow you to estimate your due date by entering in specific information. You'll be asked to enter the cycle of your periods. The default is 28 days since this is considered the average length of menstruation. But many women have shorter or longer cycles and these due date calendars take this into account when helping you figure out when your baby will be born. You'll then be asked to enter the date of the first day of your period. The calendar automatically figures out your estimated due date based on the information you provided. Some calendars also provide the estimated conception date and breaks down the date of the beginning and end of each trimester.

Accuracy of the Estimated Due Date

Online due date predictors and calculators tend to be accurate assuming that the information you entered is correct. Women who have irregular cycles may have difficulty determining their due dates since it can be hard to figure out when ovulation and conception occurred. Often women with irregular cycles who don't know how far along they are in their pregnancy require an ultrasound to assess the size of the fetus. Based on the size of the fetus and the uterus, a due date can be estimated to within two weeks. But to be as accurate as possible, the ultrasound needs to be completed early in the pregnancy. It's harder to determine due date with an ultrasound later in pregnancy.

Due dates are always estimated regardless of the way they've been determined. Few babies have precisely a 40 week gestation period and due dates. Statistically only five percent of women give birth on their due date. It's common for a baby to be born up to two weeks before the date and within two weeks after the date.

Factors the Cause an Early Birth

An early birth is considered any birth before 37 weeks. Thirty seven weeks is full term so you're not considered to have an early baby if your baby is born at this time. Reasons for premature birth aren't clear. There is some connection to premature birth and poor nutrition in pregnancy, smoking, diabetes, cervical incompetence or a multiples pregnancy. But women in good health who do everything right during their pregnancies according to medical professionals can still give birth prematurely.

Premature labor is commonly caused by a rupture of the membranes possibly from a vaginal infection or excessive amniotic fluid. If your membranes rupture at 37 weeks or later, don't be worried. Since the baby is considered full term at this point, it just means the baby is fully developed and ready to meet the world.

Factors That Cause a Late Birth

Some statistics suggest that about 70 percent of babies are born after their due date. Due dates are only an estimate and you should be prepared to have the baby any time between 38 weeks to 42 weeks. First time mothers tend to have their babies past their estimated due dates more often according to the University of Chicago Medical Center. The Center also determined that Caucasian women tend to generally have an eight day longer gestation period than women with African or Asian ancestry who often have their babies before their estimated due dates.