Posts Tagged ‘due date’

Why is 39 weeks so important?

Thursday, March 30th, 2017

midwife measuring pregnancy bellyIf your pregnancy is healthy, it is best to wait for labor to begin on its own. And if you do decide to induce labor, ask your provider if you can wait until at least 39 weeks.

Most people think that pregnancy lasts 9 months. But that isn’t exactly true. Pregnancy usually lasts about 40 weeks (280 days) from the first day of your last menstrual period (also called LMP) to your due date. A first trimester ultrasound can also help to determine your due date.

In the past, a pregnancy that lasted anywhere between 37 to 42 weeks was called a term pregnancy. Health care providers once thought this 5-week period was a safe time for most babies to be born.

But experts now know that scheduling your baby’s birth a little early for non-medical reasons can cause problems for both mom and baby. Getting to at least 39 weeks gives your baby the time he needs to grow.

Why is 39 weeks so important?

Here’s why your baby needs 39 weeks:

  • Important organs, like his brain, lungs and liver, get the time they need to develop. At 35 weeks, a baby’s brain weighs just two-thirds of what it does at 39 weeks.
  • There is more time to gain weight. Babies born at a healthy weight have an easier time staying warm than babies who are born too small.
  • Your baby will be able to feed better. Babies born early can sometimes have difficulties with sucking, swallowing, and staying awake long enough to eat.
  • Your baby is less likely to have vision and hearing problems after birth.

Why can scheduling an early birth cause problems?

There are some risks associated with inducing labor:

  • Your due date may not be exactly right. Even with an ultrasound, your due date can be off by as much as 2 weeks. If you schedule an induction and your due date is wrong, your baby may be born too early.
  • Pitocin, the medication used to induce labor, can make contractions very strong and lower your baby’s heart rate.
  • You and your baby have a higher risk of infection if labor doesn’t begin soon after your water breaks.
  • If the medications used to induce labor do not work, you may need to have a c-section.

What if there are problems with your pregnancy?

You may not have a choice about when to have your baby. Your provider may need to induce labor to help keep you and your baby safe. If your provider does decide to induce labor for the health and safety of you and your baby, you can learn more about how labor is induced on our website.

Remember: If your pregnancy is healthy, it is best to let labor begin on its own. If you and your baby are healthy, and you and your provider decide to induce labor, make sure you wait until at least 39 weeks. Healthy babies are worth the wait!

Pregnant? How far along are you in your pregnancy?

Monday, March 28th, 2016

pr_mr_lg_ultrasound1Many health care professionals will begin to estimate how far along you are in your pregnancy by asking you when the first day of your last menstrual period (LMP) was. But the development of your baby does not begin until conception – which is after your last period.

Are you confused? Let me explain…

Your pregnancy has two ages, gestational age and fetal age. Both are measured in weeks but they will be different numbers. Your gestational age is the age of the pregnancy from the first day of your last normal menstrual period. Your fetal age is the actual age of your growing baby from the day you conceived.

Health care providers use gestational age when dating a pregnancy. It is very difficult to determine an accurate date of conception, so your health care provider may estimate when you conceived based on the first day of your last period. This is your gestational age.

While your provider will use your LMP to initially date your pregnancy, according to the American Congress of Obstetrics and Gynecologists (ACOG), an ultrasound measurement of your baby in the first trimester is the most accurate method of confirming your gestational age. Keep in mind, after a first trimester ultrasound, your due date may be adjusted.

Why is it important to be aware of both?

We often hear from pregnant women that their baby’s development is not matching up with how far along they are in their pregnancy. For example, one question we received, the woman was 12 weeks pregnant but her baby was measuring 10 weeks along.  It is important to confirm with your provider that your gestational age is 12 weeks and your fetal age is 10 weeks – which means your pregnancy is on track. (Keep in mind that there may be other reasons why a baby is not developing on a typical schedule. If you are concerned, speak with your prenatal provider.)

Not sure how far along you are? Our due date calculator, will date your pregnancy based on gestational age.

Still have questions? Text or email us at AskUs@marchofdimes.org.

Due date calculator

Tuesday, March 19th, 2013

Pregnancy usually lasts 280 days (40 weeks) from the first day of the woman’s last menstrual period. Here’s a link to our interactive Due Date Calculator that will help you estimate the date your baby will arrive.

Remember, though, that this calculator is a general guide: every pregnancy is unique, and sometimes babies arrive sooner or later than expected. Always talk to your health care provider about your due date. And be sure you know the signs of preterm labor and what to do, just in case.