Postmaturity  also known as dysmaturity is used to describe babies born after 42 weeks. The normal length of pregnancy is  37 to 41 weeks. Early term is  37 to 38 weeks and 6 days. Full term is  39 weeks to 40 weeks and  6 days. Late term is 41 weeks to 41 weeks and 6 days. Very few babies are born at 42 weeks or later. Other terms  used to describe these  births include post-term, postmaturity, prolonged pregnancy and post-date pregnancy.


Causes of postmaturity in the newborn

It is not known why some pregnancies last longer than others. Sometimes the pregnancy may be off because the mother is not sure of her last menstrual period. Getting the date wrong will mean the baby will be born earlier or later than expected. The most accurate way to tell the date of a  pregnancy is through an ultrasound in the first trimester unless the date of conception is specifically known such as an in vitro fertilization.


Who is at risk ?

The risk increases when the mother has had a post term pregnancy before. After one post term pregnancy, the risk of anther post term pregnancy increases  by 2 to 3 times. Other minor factors include the following :

  • First pregnancy
  • Male baby
  • Older mother
  • Obese Mother
  • Mother or father with personal history of post maturity
  • White mother

What are the symptoms of postmaturity in the newborn ?

Some of the symptoms include the following :

  • Dry, loose peeling skin
  • Overgrown nails
  • Large amount of hair on the head
  • Visible creases on the hand and sole of feet
  • Small amount of fat on the body
  • Green , brown  or yellow coloring of the skin from baby passing stool in the womb
  • More alert and wide eyed

How is postmaturity treated ?


Your healthcare provider may decide to start labor early depending on certain factors. The baby’s heart beat will be monitored with an electronic monitor during labor. This  will spot changes in the heart rate caused by low oxygen levels. Changes in your baby’s condition may warrant a cesarean delivery.


Post term babies will be monitored for breathing problems caused by baby breathing in fluid containing the first stools (meconium). Blood test will also be done to check for low blood sugar.


Complications that may be associated with postmaturity includes the following :


Content Sources
Postmaturity in the Newborn. Stanford Children’s Hospital. Accessed October 29th, 2019

Postmaturity in the newborn. University of Rochester Medical Center. Accessed October 29th, 2019

Postmaturity. Children’s Hospital of Philadelphia. Accessed October 29th, 2019

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