Problems in Prenatal Development

1. Problems in Prenatal Development

2. Losing a Baby • Miscarriage – when developing baby dies prior to the 20th week of pregnancy • About 15% of pregnancies end in miscarriage • Medical experts not sure of cause • Stillbirth – when baby dies after the 20th week of pregnancy • Occurs in 2% of pregnancies • Causes include problems with placenta, abnormal chromosomes, poor growth, and infections

3. Losing a Baby • Very unexpected and painful • Stages of grief • Feel alone • May blame themselves • Couples may need support

4. Birth Defects • Some babies are born with serious problems • Problem that threatens health and is present at birth is a birth defect • Hundreds of types of birth defects • Some are mild, some are severe, and some can result in death • About 120,000 babies are born with birth defects

5. Types and Causes of Birth Defects • Some cause abnormality in the structure of the body • Misshapen foot • Extra or missing finger • Some cause one or more systems of the body not to function properly • Blindness • Deafness • Mental retardation

6. Types and Causes of Birth Defects • Not all are obvious at birth and may not be discovered until months or years later • Scientists do not fully understand • Four main causes • Factors in the environment • Hereditary factors • Errors in chromosomes • A combination of environmental and hereditary factors

7. Environmental Causes • First few weeks of conception are important for development of embryo • Choices the mother makes are important • Environmental factors that can affect embryo • Nutritional balance • Diseases or infections • Harmful substances • Some medicines • Air pollution • Exposure to X-rays, radiation, or chemicals

8. Hereditary Causes • Every person has approximately 20,00 to 25,000 genes • Genes direct growth and development of body systems • In most cases, a single copy of a faulty recessive gene will have no effect on development • Sometimes both parents pass on same faulty gene, which causes birth defect. • Called recessive heritance • Two conditions caused by this • Tay-Sachs disease • Cystic fibrosis

9. Hereditary Causes • Sometimes child will inherit a dominant defective gene • Only necessary for one parent to pass on gene for child to have defect • Called dominant inheritance • Huntington’s disease • Some inherited condition only affect one gender • Color blindness, Duchenne muscular dystrophy, and hemophilia usually only affects males

10. Errors in Chromosomes • Several types of birth defects are caused by problems in number or structure of chromosomes. • Can occur when egg or sperm are developing\ • Most common birth defect of this type • Down Syndrome – may have some degree of mental retardation, plus physical problems • One in 800 babies has this condition • Instead of having two copies of chromosome 21, child has three

11. Interaction of Heredity and Environment • Some defects caused by a combination of hereditary and environmental factors • Cleft lip • Cleft palate • Spina bifida • A genetic predisposition, or tendency, for spina bifida, combined with certain medications during pregnancy will increase chance of defecgt

12. Prevention and Diagnosis of Birth Defects • Can be challenging for a child born with a serious, or severe, birth defect to lead a normal, productive life. • Family members are affected by emotional and financial strain • Not all birth defects can be anticipated or controlled

13. Prevention and Diagnosis of Birth Defects • Several things couples can do to lessen the chance of having a child with birth defects • Get a checkup prior to getting pregnant to evaluate overall health • Discuss lifestyle changes • Stop smoking and drinking • Prenatal care after woman becomes pregnant • Do not take medications without doctors approval

14. Genetic Counseling • Some couples seek genetic counseling to assess their risk based on their genes • May have family history of defects • Counselors can explain options and risks • Counselor evaluates family history • Medical history • Diseases • Causes of death of family members

15. Genetic Counseling • Counselor may request • Physical exams • Blood and body tissue samples • Counselor can then determine risks of birth defects

16. Prenatal Tests • Some common prenatal tests • Alpha-fetoprotein (AFP) – performed between weeks 15 and 20 • AFP is a protein produced in the liver of the fetus and abnormal levels can indicate defect • Ultrasound • Uses sound waves to make a video image of baby • Helps monitor baby’s development, pinpoint baby’s age, and detect certain birth defects • Problems with skeletal, circulatory, and nervous systems can be detected

17. Prenatal Tests • Ultrasound • Usually done near 20th week of pregnancy • Many doctors now do 3D ultrasounds, which give more detail • Poses no threat to baby or mother • Amniocentesis • Withdraw a sample of amniotic fluid • Some cells from fetus are in fluid, which is then taken to the lab and tested • Used to test for Down Syndrome when mother is over age of 35 • Involves some risks only if strong reason to do so and done in 15th and 20th week of pregnancy

18. Prenatal Tests • Chorionic Villi Sampling • Uses sample of tissue from membrane that encases the fetus • Samples are cut or suctioned off • Used to tests for same disorders as amniocentesis • Done much earlier • New Prenatal Diagnosis • Several methods are in experimental stages • Possible to view fetus through a laparoscope • Doctors can get samples of fetal blood and tissue and even do surgery on unborn child • Carry risks