How Accurate is a Due Date Calculator?

November 12, 2012

How Accurate is a Due Date Calculator?

Generally speaking, there are two ways to measure a pregnancy: through gestation or through a woman’s last menstrual period. A due date calculator is part of the latter.

How to Calculate Your Pregnancy

A due date calculator calculates pregnancies at 10 lunar months or at 40 weeks. The last menstrual period calculation can be used if your ovulation took place during day 14 of the pregnancy, while the gestation calculation can be used if your ovulation date will result in a pregnancy that lasts 38 weeks. Therefore, if you know exactly when your ovulation was, you can either calculate where your pregnancy currently lies through either of the methods mentioned above.

How Do Ultrasounds Do It?

Ultrasounds might give you odd dates since th

ey don’t always use gestation, the last menstrual period or a due date calculator to calculate your pregnancy. Instead, they sometimes take the development rate and change your due date, depending on where your baby’s scale is. In some cases, the doctor might even move your entire due date because of this, no matter how sure you are of when your baby will be conceived.

There is only a certain set of potential size variability that babies can reach during a pregnancy, so the majority of them will reach a certain size during a certain point of the pregnancy. Later on during the pregnancy, the individual variability amongst babies will be higher, though, so their date estimates and sizes will be less and less accurate. However, almost every baby will be at two inches long after 13 weeks. So, if they are a little larger than that by 13 weeks, then your doctor might add an additional day onto your ultrasound estimate.

What Should You Do, Then?

Ideally, you should try and use a due date calculator to calculate your actual due date during the pregnancy – provided there are no complications so far, that is. If you do experience complications during your pregnancy, then things might change for you. In this case, you should get ready earlier on and try to find out how early or late you might give birth.

A lot of women set their hearts on a specific due date, though, which is why a due date calculator would be ideal for them. This will help them prepare for their actual due date and ensure that they don’t let it pass by or get upset about it. In the end, it really will just depend on you as a mother.

Category: Articles