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Why Baby Needs a Full 40 Weeks of Pregnancy

By Helen M. Hurst DNP, RNC, APRN-CNM

Why Baby Needs a Full 40 Weeks of Pregnancy

Your baby needs a full 40 weeks of pregnancy

As you get closer and closer to your due date, it probably seems like your baby will never arrive. You’re having a hard time sleeping, your back hurts, your feet are swollen and just when you finally get comfortable, you have to use the bathroom again. But don’t give up with the finish line in sight. Your last few weeks of your pregnancy are very important to your baby.

Problems with Being Born Early

Did you know that babies who are born even a few weeks early could have immediate and life-long health issues, including struggles feeding, breathing and staying warm, premature brain or lung development and problems maintaining stable blood sugars?
Babies born early also have increased lifetime risks for diabetes, heart disease, high blood pressure and attention deficit hyperactivity disorder if born before the full 40 weeks.

Get to Term

In those last few weeks, your baby will gain weight more rapidly so she has enough fat to hold a normal body temperature. Her lungs, liver and brain will also continue to rapidly change—at 35 weeks her brain is only 2/3rds of the size it will be at term.

You may be told that your baby is “measuring big” but this is no indication of whether her lungs are mature. Baby’s liver is also maturing: Being born early makes her more prone to developing newborn jaundice—a yellowing of the skin that shows her liver can’t rid her body of a substance called bilirubin. If baby has jaundice, she may have to stay in the hospital under special lights, and in severe cases, her brain could be affected.

During those last few weeks, your body gives baby a big boost of antibodies that helps her fight infection once born. And being born too early could hamper breastfeeding, because the brain development baby needs to coordinate sucking and swallowing doesn’t happen until the last few weeks of pregnancy.

Worst of all, many of these problems could result in you having to leave your baby at the hospital when you are discharged home, which is very distressing for any mom!

Just How Long Can Baby Stay in There?

Most providers will support women and their babies gestating for up to 42 weeks, after which time the uterine environment may begin to deteriorate to the degree that it puts your baby at risk. During weeks 40-42, your provider may ask you to:

  • Perform daily kick counts with baby and call with any changes
  • Take a non-stress test, which uses a fetal monitor to watch baby’s heart rate for 20-40 minutes. This is usually done at the provider’s office
  • Undergo a biophysical profile via ultrasound to observe baby’s breathing, heart rate, amniotic fluid amount, and body movements


inductiondecisions_web Nurse expert Cathy Ruhl explains why it’s important to wait for labor to start on its own.





Nurses share 40 Reasons to Go The Full 40 Weeks of Pregnancy in our GoTheFull40.com zone!





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