1. 1)germinal Period (0-2 weeks)
Prenatal development is divided into three main Periods
1)germinal Period (0-2 weeks)
Conception occurs in fallopian tubes
Cell differentiation
Rapid cell division
42% of conceptions successfully implant in uterus
Blastocyst
A cell mass that develops from the zygote in the germinal period and forms a hollow sphere in preparation for implantation.
the organ that surrounds the developing embryo and fetus, sustaining life via the umbilical cord…attached to the wall of the uterus
Implantation
the process, beginning about 10 days after conception, which the developing organism burrows into the placenta that lines the uterus, where it can be nourished and protected as it continues to develop

2. 3) Fetus: From the Ninth Week Until Birth
Embryo: from the third through the eighth week
major organs develop
at eight weeks, organism is less than 2˝ long
3) Fetus: From the Ninth Week Until Birth
Sex organs develop
Brain development is significant
Age of viability occurs around 22 weeks
The Third Month
the fetus has all its body parts
weighs approximately 3 ounces, about 3 inches long
growth is rapid
fetus is too small survive outside of the womb

3. The Middle Three Months: Preparing to Survive
in the fourth, fifth and sixth months the heartbeat becomes stronger
the cardiovascular system more active
the brain increases about six times in size
Digestive and excretory systems develop
age of viability
twenty-two weeks after conception a fetus can survive outside the mother’s uterus if specialized medical care is available

4. The Final Three Months: From Viability to Full Term
life outside the womb is possible
born in the seventh month requires intensive hospital care and life-support systems
difference between preterm and newborn is the maturation of neurological, respiratory, cardiovascular systems
Brain development in the cortex

5. Risk Reduction
toxins, illnesses and experiences can harm a developing person before birth
teratology
a science of risk analysis, the study of birth defects
teratogens
Agents and conditions that can impair prenatal development and result in birth defects and death.
behavioral teratogens
Agents and conditions that can harm the prenatal brain, impairing the future child’s intellectual and emotional functioning

6. Risk Reduction Determining Risk risk analysis
the science of weighing the potential effects of a particular event, substance, or experience to determine the likelihood of harm
Timing of Exposure
critical period
In prenatal development, the time when a particular organ or other body part of the embryo or fetus is most susceptible to damage by teratogens

7. Risk Reduction Amount of Exposure Threshold effect Interaction effect
a situation in which a certain teratogen is relatively harmless in small doses but becomes harmful once exposure reaches a certain level (the threshold)
Interaction effect
the result of a combination of teratogens. Sometimes risk is greatly magnified when an embryo or fetus is exposed to more than one teratogen at the same time

9. Genetic Vulnerability
Developing organisms genes determine if a teratogen will have an effect.
Dizygotic twins experience different effects.
Some nations have increased rates of some defects and decreased rates of others.
Males are at greater risk

10. Risk Reduction
Protective Measures
Benefits of Prenatal Care

11. Method used to make Prenatal Genetic Diagnoses
Ultrasound
Chorionic Villus Sampling
Alpha Fetoprotein Screen
Amniocentesis
Genetic Counseling 11

12. Ultrasound
Sound wave echoes are used to form a live video image of a fetus
Can be used for diagnosis of birth defects
Very safe
Tim Brown/Getty Images 12

13. Chorionic Villus Sampling (CVS)
Conducted at 9-12 weeks gestation
Needle is inserted
Fetal cells are removed and tested for various genetic disorders 13

14. Alpha Fetoprotein Detection
Conducted at weeks gestation
Mother’s blood is assayed for AFP levels
high levels indicate possible neural tube defects
low levels indicate possible chromosomal abnormalities 14

15. Amniocentesis Conducted at 15-19 weeks gestation
Needle is inserted into abdomen
Fetal skin cells are removed and assayed for genetic abnormalities
Low risk 15

16. Genetic Counseling Birth defects Genetic counselors
Occur in 1/33 births
Are the leading cause of infant death
Genetic counselors
Help determine risk
Provide counseling for families with an infant born with genetic problems 16

17. Genetic Counseling Recommended for
Parents of children with genetic disorders
Parents with a known genetic disorder
Women who have repeatedly miscarried
Older pregnant women
Couples of certain ancestry/ethnicities
Couples who are related to each other 17

18. Normal Uncomplicated Birth
The Newborn’s First Minutes

19. Birth Complications

20. The Birth Process The Newborn’s First Minutes Apgar scale
a quick assessment of a newborn’s body functioning.
color
heart rate
reflexes
muscle tone
respiratory effort

21. The Birth Process Variations medical Intervention birth complications
cesarean section
fetus is removed through incisions in the mother’s abdomen and uterus
Home birth
birth complications
includes anything in the newborn, the mother, or the birth process itself that requires special medical attention
anoxia
a lack of oxygen that, if prolonged during birth, can cause brain damage or death to the baby

22. The Birth Process Birthweight
the average weight of a newborn is 7½ lbs. (normal range is 5 ½ to 9 pounds)
LBW is considered less than 5½ lbs.
VLBW is considered less than 3 lbs. 5 oz.
ELBW is considered less than 2 lbs. 3 oz.
preterm is less than 35 weeks (usually LBW, but not always)
lifestyle choices
e.g., cigarette smoking accounts for 25% of LBW births worldwide!
maternal malnutrition
multiple births
prescription drugs
maternal obesity

23. The Birth Process
Some babies are born small for their gestational age (SGA)
Ex. 5 lb. Newborn
These babies gained weight too slowly during the prenatal period
More concerning than a underweight pre-term baby
Failure to thrive
Causes (problems with placenta and umbilical cord, maternal illness and maternal drug use)

24. The Birth Process Social Support Mother’s Role Postpartum Depression
Help from fathers
Postpartum Depression
8-15% of women experience postpartum depression, a sense of inadequacy and sadness after birth.
includes irritability, sleep and eating disruptions, sadness, feeling overwhelmed and inadequate as a mom, no interest or overly worried about baby.