Problems in Prenatal Development Section 4.2

Losing a Baby A baby’s health is a major concern for all expectant parents – Most babies develop normally and are born health – Sometimes the baby does not develop normally and this can lead to death When the developing baby dies prior to the 20 th week of pregnancy, this is called miscarriage – About 15% of recognized pregnancies end in miscarriage After the 20 th week this is called a stillbirth – About 2% of pregnancies Most common causes – Problems with the placenta – Abnormal chromosomes – Poor growth – Infections

Birth Defects Some babies survive pregnancy, but are born with serious problems that threaten their health or even their lives A serious problem that threatens a baby’s health, and is present at birth, is called a birth defect There are hundreds of types of birth defects – Approx. 120,000 babies are born each year in the US with a birth defect

Types and Causes of Birth Defects Types – Some cause abnormality in the structure of the body – Some cause one or more systems of the body to not function properly – Not all are obvious at birth Four main causes for birth defects – Factors in environment – Heredity factors – Errors in chromosomes – Any combination of environmental and hereditary factors

Prevention and Diagnosis of Birth Defects It can be challenging for a child born with a serious or severe birth defect to leave a normal, productive life Advances in treatment and support groups are helping children and their families cope Not all causes of birth defects can be anticipated or controlled

Prevention and Diagnosis of Birth Defects There are several things couples can do to lessen the chances of having a child with birth defects – If a couple is planning to become parents they should get a checkup to evaluate overall health – Woman should quit smoking/drinking prior to trying to conceiving – Some seek genetic counseling

Prevention and Diagnosis of Birth Defects Prenatal testing – Alpha-fetoprotein (AFP): Blood test on expectant mothers weeks looking for the AFP protein produced in the liver of the fetus – Ultrasound: Test that uses sound waves to make a video image of an unborn baby. Sonogram is that image. – Amniocentesis: Removing a sample of the amniotic fluid surrounding unborn baby to get cells from the fluid – Chorionic Villi Sampling: Sample of the tissue from the membrane that encases the fetus. More risky than amniocentesis but can be done earlier between 10 th and 12 th week – New technology is being developed every day!