1. Problems in Prenatal Development
Chapter 8

2. Miscarriage
Miscarriage—spontaneous loss of the pregnancy after less than 20 weeks of fetal development
the zygote, embryo, or fetus dies and is expelled from the mother’s body
between 15-20% of known pregnancies end in miscarriage
many other pregnancies end before the mother even knew she was pregnant

3. Miscarriage Myths
physical activity, stress, and minor falls are NOT believed to cause the loss of pregnancy
Miscarriages that occur early in pregnancy are usually due to a genetic abnormality
Most often the problem was not inherited, but happened by chance
Couples could not have done anything to prevent the miscarriage
Most of these couples are able to have a successful pregnancy later

4. Risk Factors for Miscarriage
age: women over age 35 are at a greater risk
having had a previous miscarriage
family history of miscarriage
certain diseases or infections
exposure to hazards during pregnancy such as: alcohol, drugs, smoking, heavy caffeine use, or certain chemicals

5. Stillbirth
Stillbirth if the fetus dies after the 20th week of pregnancy
occurs in 1 out of 200 pregnancies
death can occur during labor or delivery, but more often it occurs before labor
causes vary and sometimes no cause can be found

6. Ectopic Pregnancy
Ectopic Pregnancy—when a fertilized egg implants outside the uterus
in most cases, the egg implants in the fallopian tube
another name for ectopic pregnancy is: Tubal Pregnancy
without the nourishment and protection of the uterus, the embryo cannot survive
Risk to mother’s health: as embryo grows, it may eventually burst the fallopian tube
This can cause life threatening bleeding
-physician must end a discovered ectopic pregnancy

7. Premature Labor and Birth
Premature Labor and Birth—when labor and/or birth occurs before the 37th week of pregnancy
about 1 out of every 10 babies is premature
Premature babies have less time to develop in the uterus
babies with the most serious health problems: babies born before 26 weeks and weigh less than 2 pounds
These babies underdeveloped lungs, fluid accumulation in the brain, seizures, and growth and learning delays

8. Prenatal Testing
Various tests are used to determine if the fetus has a birth defect or other health problem
Some tests reveal other info such as if the new arrival will be a boy or a girl
Some tests, such as various blood tests are routinely given to almost all pregnant women
Other tests are warranted only when there is reason to suspect a problem
A family history of genetic defect is another possible reason for prenatal testing
EVEN WHEN A DR. RECOMMENDS PRENATAL TESTING, THE MOTHER-TO-BE CHOOSES WHETHER OR NOT TO UNDERGO THE PROCEDURE
Most prenatal tests involve some risks

9. Ultrasound Imaging
Ultrasound imaging—uses sound waves to create video and still images of the fetus inside the uterus
A woman lies on a padded table
A technician applies thick, clear gel to woman’s abdomen and rubs a transducer (handheld device) over the area covered by the gel
Sound waves bounce off the fetus’s bones, tissues, and organs producing images that are viewed on a monitor
ultrasound image—often called a sonogram
involves little or NO risk
Used to check fetal position and movement, measure fetus’s heart rate, and asses whether prenatal development is proceeding normally
can reveal the fetus’s gender and the presence of twins

10. Amniocentesis
Amniocentesis—test involving removing a small amount of amniotic fluid that surrounds the developing fetus
while viewing an ultrasound, a doctor guides a needle thru the abdomen and wall of the uterus
performed at 15 to 18 weeks of pregnancy, but is sometimes done as early as 11 weeks
slightly increases the risk of miscarriage so it is NOT routinely offered
reasons for amniocentesis:
check for genetic or chromosomal problems
if woman is over age 35
if there is a family history of genetic disorders
if blood tests indicate a problem

11. Amniocentesis

12. Chorionic Villi Sampling
Chorionic Villi Sampling (CVS)—take a sample of cells from the placenta
What are Chorionic Villi?
They are microscopic, fingerlike projections on the placenta
insert a tube/needle thru abdomen or vagina
Ultrasound is used to guide the tube or needle
The cells are removed and checked for their genetic structure
Doctors can use this to test for about 200 genetic defects
Chorionic Villi Sampling is preformed at 10 to 12 weeks of pregnancy
higher risks only done if a serious problem is suspected

13. Chorionic Villi Sampling