Third Trimester

Fetal Development

Week 24-25

the fetus at 6 months
A protective waxy substance called Vernix covers the skin. By birth, most of the Vernix will be gone but any that is left is quickly absorbed. Fetus has a hand and startle reflex. Footprints and fingerprints are forming. Fetus practices breathing by inhaling amniotic fluid into its developing lungs. At 24-25 weeks there is a 50-75% chance of survival if born, and is considered viable at this stage. Viability refers to the ability of a fetus to survive outside the uterus without artificial support.

Weeks 26 – 28

the unborn child at 7 months
Rapid brain development occurs during this period and the nervous system is able to control some bodily functions. The fetus’ eyelids now open and close. There is now a more than 90% chance of survival if the fetus is born at this point.

Weeks 29 – 32

There is a rapid increase in the amount of body fat the fetus has. Rhythmic breathing occurs, but the lungs are not yet mature. The fetus sleeps 90-95% of the day. At this point the survival rate is above 95% if the baby is born.

the unborn child at 8 months

Weeks 38 – 40

The fetus is considered full-term. Lanugo is gone except on upper arms and shoulders. Hair on the baby’s head is now coarser and thicker. The lungs are mature. The average weight of the baby at this point is seven and a half pounds. At birth the placenta detaches from the uterus and the umbilical cord will be cut as the baby takes his first breaths of air. Breathing will trigger changes in the heart and bypass arteries forcing all blood to now travel through the lungs.

newborn baby

About the Photos

Many of the amazing pictures shown here were taken from the very excellent Nine Month Miracle CD ROM, by A.D.A.M. Software, Inc.,the book A Child Is Born by the famous Swedish photographer Lennart Nilsson, and the handbook When You were Formed in Secret, by Gary Bergel. Complete references are listed below. More about how these photos were taken. Photos appearing on this web site are reproduced under “fair use” terms for the purpose of public education. For permission to use these photos for commercial purposes, please contact the sources indicated below.

Sources

  • Nine Month Miracle (CD ROM software) , A.D.A.M. Software, Inc., 1600 RiverEdge Parkway, Suite 800, Atlanta, GA, 30328.
  • The First Nine Months of Life, (brochure) Focus on the Family, Colorado Springs, CO, 1995.
  • Medline Plus, a service of U.S. National Library of Medicine and the National Institute for Health
  • Wellness Center
    Fetal Development Pages
  • Pain and its Effects in the Human Neonate and Fetus, THE NEW ENGLAND JOURNAL OF MEDICINE, Volume 317, Number 21: Pages 1321-1329, 19 November 1987.
  • Pediatricweb.com: Pre-Term Birth Information.
    • Journal of Maternal-Fetal and Neonatal Medicine 2008, Vol. 21, No. 2, Pages 115-121.
    • March of Dimes (http://www.marchofdimes.com/professionals/14332_1196.asp)

Recommended Books, Videos and Software

  • A Child Is Born by Lennart Nilsson (also in paperback). The pictures are truly amazing (if you are pregnant or even thinking about getting pregnant, you must see this book!).
  • Nova: The Miracle of Life includes a detailed account of how a baby is formed, from conception to birth, complete with prenatal footage. Order from Amazon.com.
  • Nine Month Miracle, A.D.A.M. Software, Inc.: Join Adam & Eve as they experience life’s greatest miracles – the birth of their child. Nine Month Miracle is a wonderful way for the entire family to learn about conception, childbirth and everything in between.
  • Or visit our bookstore for more recommended educational materials