Table of Contents
- Overview
- Prevention
At birth, the baby's lungs are filled with
Once the umbilical cord is cut and the baby takes the first breath, a number of changes occur in the infant's lungs and circulatory system:
- Increased oxygen in the lungs causes a decrease in blood flow resistance to the lungs.
- Blood flow resistance of the baby's blood vessels also increases.
- Amniotic fluid drains or is absorbed from the respiratory system.
- The lungs inflate and begin working on their own, moving oxygen into the bloodstream and removing carbon dioxide by breathing out (exhalation).
TEMPERATURE REGULATION
A developing baby produces about twice as much heat as an adult. That heat dissipates as blood flows into the mother's circulation via the placenta and is cooled. A small amount of heat is removed through the developing baby's skin, the amniotic fluid, and the uterine wall.
After delivery, the newborn begins to lose heat. Receptors on the baby's skin send messages to the brain that the baby's body is cold. The baby's body then creates heat by shivering and by burning stores of brown fat, a type of fat found only in fetuses and newborns.
LIVER
In the fetus, the liver acts as a storage site for sugar (glycogen) and iron. When the baby is born, the liver has various functions:
- It produces substances that help the blood to clot.
- It begins breaking down waste products such as excess red blood cells.
- It produces a protein that helps break down bilirubin. If the baby's body does not properly break down bilirubin, it can lead to
newborn jaundice .
GASTROINTESTINAL TRACT
A baby's gastrointestinal system doesn't fully function until after birth.
In late pregnancy, the fetus produces a tarry green or black waste substance called meconium. Meconium is the medical term for the newborn infant's first stools. Meconium is composed of amniotic fluid, mucus, lanugo (the fine hair that covers the baby's body), bile, and cells that have been shed from the skin and intestinal tract. In some cases, the baby passes stools (meconium) while still inside the uterus.
URINARY SYSTEM
Review Date: 11/02/2009
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of
Pediatrics, University of Washington School of Medicine. Also
reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
