Prenatal Development

Chapter 4-1Child Development

Prenatal Development

• How Conception Occurs• Inner lining of uterus

thickens• Every 28 days, an ovum

is released into fallopian tubes

• If a sperm fertilizes the egg while in the fallopian tube…

• CONCEPTION occurs

Prenatal Development

• Time Frames• Ovum usually lives for

24-48 hours• Sperm is capable of

fertilizing for 48 to 72 hours

• During a woman’s cyle, there are 3-4 fertile days each month

Fertilization of an Egg

Real Life Pictures of Ovulation

Prenatal Development

• Germinal Stage• Lasts about two weeks• Cell division begins

while still in the fallopian tube

• After about 4 days, zygote reaches the uterus and implants

• Zygote is the size of the head of a pin

Prenatal Development

• Embryonic Stage• Lasts from 3rd through

8th weeks• Embryo grows rapidly• Lots of changes occur

Ultrasounds – 3 weeks, 8 weeks

Prenatal Development

• Organs and Body Systems Develop• Cells separate and turn in to major systems of

body • Neural tube (becomes the brain/spinal cord)

develops at 27 days after conception• Brain then takes over development• Very sensitive to drugs and alcohol

Prenatal Development

• Amniotic Sac• Sac filled with fluid forms

around the embryo• Amniotic fluid protects

the baby• Cushions the baby from

bumps or falls• Embryo is about 1” long• Floats freely in fluid

Prenatal Development

• Placenta and Umbilical Cord• Placenta absorbs oxygen and

nourishment from mother• Sends to baby through

umbilical cord • takes carbon dioxide and

other waste away• Placenta and umbilical cord

provide everything baby needs until birth

Prenatal Development

• Umbilical cord • Thick and firm• Like a garden hose filled

with water• Usually not flexible

enough to loop around fetus

Prenatal Development

• Fetal Stage• From 8th week until birth• Baby is called “fetus”• Buds for 20 baby teeth

appear• Vocal chords develop• Digestive system works• Spontaneous

movements begin

Prenatal Development

• When can Baby live outside the womb?

• At Month 7, with help• Baby gains weight • Adds fat• What does the fat do? • Helps keep Baby warm

after birth

Prenatal Development• What else is Baby up to? • Suck its thumb• Cough, sneeze, kick• Cry!• Still can change positions

• As baby grows bigger• Baby runs out of room and

assumes “fetal position”• Can no longer change

positions

3 Weeks

8 Weeks

• Biology of Prenatal Development video– http://www.ehd.org/shoppingcart/products/The-Biology-

of-Prenatal-Development.html• Ovulation video

– http://www.youtube.com/watch?v=nLmg4wSHdxQ• Graphic Medical Photos of Cervix, Uterus, etc…

– http://library.med.utah.edu/WebPath/FEMHTML/FEMIDX.html#2

• Nova Life’s Greatest Miracle• http://www.pbs.org/wgbh/nova/body/life-greatest-miracle.htm

l

• Nova’s Stem Cells• http://www.pbs.org/wgbh/nova/body/stem-cells-research.html

Prenatal Development and FruitChild Development

Source: BabyCenter.com

4 Weeks

• 4 Weeks: Baby -- now officially an embryo -- is about the size of a poppy seed.

5 Weeks

• 5 weeks: Baby has grown to the size of a sesame seed, looking more like a tiny tadpole than a human.

6 Weeks

• 6 weeks: Baby is as long as a lentil (about 1/4 inch).

7 Weeks

• 7 weeks: Baby, having doubled in size since last week, is as big as a blueberry (about 1/2 inch in length).

8 Weeks

• 8 weeks: Baby -- now comparable to the size of a kidney bean (just over 1/2 inch long) -- is constantly moving and shifting.

9 Weeks

• 9 weeks: Baby has grown to the size of a grape, weighs a fraction of an ounce, and is almost 1 inch long.

10 Weeks

• 10 weeks: Baby, now barely the size of a kumquat, weighs less than a quarter of an ounce. (Length: a little over 1 inch, head to bottom.)

11 Weeks

• 11 Weeks- Baby is now about as big as a fig. (Length: just over 1 1/2 inches, head to bottom.)

12 Weeks

• 12 weeks: Baby is, by this time, the size of a lime and weighs 1/2 ounce. (Length: just over 2 inches, head to bottom.)

13 Weeks

• 13 weeks: Baby has reached the size of a medium shrimp and weighs nearly an ounce. (Length: almost 3 inches, head to bottom.)

14 Weeks

• 14 weeks: Baby, now as long as a lemon, weighs about 1 1/2 ounces. (Length: 3 1/2 inches, head to bottom.)

15 Weeks

• 15 weeks: Baby has grown to the size of an apple and weighs about 2 1/2 ounces. (Length: 4 inches, head to bottom.)

16 Weeks

• 16 weeks: Baby measures up to an avocado, now, and weighs 3 1/2 ounces. (Length: 4 1/2 inches, head to bottom.)

17 Weeks

• 17 weeks: Baby weighs 5 ounces this week -- about as much as a turnip. (Length: 5 inches, head to bottom.)

18 Weeks

• 18 weeks: Baby is as big as a bell pepper and weighs almost 7 ounces. (Length: 5 1/2 inches, head to bottom.)

19 Weeks

• 19 weeks: Baby equals a large heirloom tomato in size and weighs 8 1/2 ounces. (length: 6 inches, head to bottom)

20 Weeks

• 20 weeks: Baby has grown as big as a banana. (Length: about 6 1/2 inches from head to bottom, and 10 inches from head to heel.)

21 Weeks

• 21 weeks: Baby -- currently the length of a carrot -- weighs about 3/4 of a pound. (Length: 10 1/2 inches, head to heel.)

22 Weeks

• 22 weeks: Baby has stretched to the size of a spaghetti squash and weighs almost a pound. (Length: nearly 11 inches.)

23 Weeks

• 23 weeks: Baby weighs about as much as a large mango -- just over a pound. (Length: more than 11 inches.)

24 Weeks

• 24 weeks: Baby is the size of an ear of corn and has caught up with an ear of corn in size and gained about 1/4 pound since last week. (Length: almost a foot.)

25 Weeks

• 25 weeks: Baby is the size of a rutabaga and rivals the average rutabaga in weight -- about 1 1/2 pounds. (Length: 13 1/2 inches, head to heel.)

26 Weeks

• 26 Weeks- Baby is as tall as an English hothouse cucumber and weighs about 1 2/3 pounds. (Length: 14 inches, head to heel.)

27 Weeks

• 27 weeks: Baby is the size of a hefty as a head of cauliflower, weighing in at almost 2 pounds. (Length: about 14 1/2 inches.)

28 Weeks

• 28 weeks: Baby is equal in weight to a Chinese cabbage -- about 2 1/4 pounds. (Length: almost 15 inches, from head to heel.)

29 Weeks

• 29 weeks: Baby is as big as a butternut squash, weight-wise -- about 2 1/2 pounds. (Length: a tad over 15 inches, head to heel.)

30 Weeks

• 30 weeks: Baby rivals a good-size cabbage in weight, tipping the scales this week at 3 pounds. (Length: about 15 3/4 inches, head to heel.)

31 Weeks

• 31 weeks: Baby now weighs as much as four navel oranges. (Length: over 16 inches, head to heel.)

32 Weeks

• 32 weeks: Baby is taking up more and more space in the uterus and weighs as much as a large jicama -- about 3 3/4 pounds. (Length: about 16 3/4 inches, head to heel.)

33 Weeks

• 33 weeks: Baby is proportioned like a pineapple when it comes to weight -- a little over 4 pounds. (Length: more than 17 inches, head to heel.)

34 Weeks

• 34 weeks: Baby has bulked up like the average cantaloupe -- to about 4 3/4 pounds. (Length: almost 18 inches, head to heel.)

35 Weeks

• 35 weeks: Baby, now as hefty as a honeydew melon at 5 1/4 pounds, doesn't have much room to maneuver in your belly. (Length: more than 18 inches, head to heel.)

36 Weeks

• 36 weeks: Baby, almost 6 pounds and still packing on the pounds at a rate of about an ounce a day, is comparable to a crenshaw melon in size. (Length: more than 18 1/2 inches, head to heel.)

37 Weeks

• 37 weeks: Baby is as lofty as a stalk of Swiss chard and weighs 6 1/3 pounds. (Length: a bit over 19 inches, head to heel.)

38 Weeks

• 38 weeks: Baby, now as long as a leek, weighs nearly 7 pounds. (Length: more than 19 1/2 inches, head to heel.)

39 Weeks

• 39 weeks: Baby matches up to a mini-watermelon, weighing a bit over 7 pounds. (Length: about 20 inches, head to heel.)

40 Weeks

• 40 weeks: Baby is probably around the size of a small pumpkin. The average newborn weighs about 7 1/2 pounds and is about 20 inches long.

Pregnancy Succession

Issues in Prenatal Development

Chapter 4.3, 4.4Child Development

Prenatal Development• Options for Infertile Couples• Adoption• Artificial insemination• Sperm injected into uterus when ovulating• In Vitro Fertilization (IVF)• Doctor places zygote in uterus• Ovum transfer• Same as in vitro but ovum has been donated• Surrogate mother• When another women becomes pregnant for you

Prenatal Development• Fertility Treatments– Women take hormones, daily shots– Can cause uncomfortable

and serious side effects– Women will often

conceive more than one baby

Prenatal Development• Losing a Baby• When baby is not developing normally, sometimes it may result in

the baby’s death

• Miscarriage• Happens before 20 weeks• 15-20% of recognized* pregnancies

• Stillbirth• Happens after 20 weeks• 2% of pregnancies• Problems with placenta, abnormal chromosomes, poor

growth and infections

Prenatal Development• Birth Defects• Affects 150,000 babies each year around the

world• Some defects are mild, some are severe• Not all defects are apparent at birth• Doctors and scientists are researching how to

prevent and treat birth defects

• NOTE ON THE NOTES: You don’t have to write the details on each defect!

Cleft Lip / Cleft Palate

• Gap in the upper lip or palate (roof of mouth) • Causes problems with eating, speech, appearance

Cleft Lip Repairs

Cleft Lip Repairs

Cleft Lip Repairs

Cystic Fibrosis

• Respiratory and digestive issue• many die before 18 • very salty sweat and cough that doesn’t go

away• more likely to affect Caucasians than African

or Asian American’s

Cerebral Palsy

• Variety of motor problems: lack of coordination, stiffness, paralysis, difficulty with speech

Down Syndrome

• Group of problems that may include mental retardation, problems with heart, blood, digestive system, poor muscle tone

• caused by extra chromosome• can be detected by amniocentisis

Muscular Dystrophy

• Weakness and shrinking of muscles• usually starts between age 2-6• usually hereditary• Mainly affects males but some females

PKU

• Body is unable to process a specific protein that is in almost all foods

• All newborns are tested for this by law. • Special diet can reduce brain damage.

Sickle Cell Anemia

• Malformed red blood cells affects supply of oxygen• Symptoms include tiredness, lack of appetite, pain, early death• African American’s are more likely to have this condition

Spina Bifida / Hydrocephalus

• Incompletely formed spinal cord leads to stiff joints, difficulty moving legs, problems with kidneys and urinary tract

• 70/100 with Spina Bifida also have Hydrocephalus, excess fluid around brain

• Amniocentisis and blood tests can reveal before birth

• Fetal Alcohol Syndrome (FAS)– Passed directly to child– Has no cure and lasts forever– 20% of babies born with

FAS die before age 1– Those who survive may have– Facial deformity– Heart defects– Mental retardation

• Fetal Alcohol Effects– Less severe than

FAS but similar symptoms

Fetal Alcohol Syndrome

Tay-Sachs Disease

• Babies lack a chemical in their blood that makes them unable to process fats• Usually leads to death by age 4• Most common in families of European Jewish decent• No cure for disease, just make the child comfortable

Causes of Birth Defects• THIS IS WHERE YOU START WRITING AGAIN.

• Environmental causes• Nutritional balance of mother’s diet• Diseases or infections that mother has• Drugs, alcohol, prescription or OTC medicine• Exposure to chemicals, radiation (x-rays), etc.

Causes of Birth Defects• Hereditary causes• Tay-Sachs, Cystic Fibrosis• Errors in Chromosomes• Down Syndrome• Interaction of Heredity and Environment• Cleft palate, cleft lip

• We don’t always know why

Prevention / Diagnosis of Birth Defects• What can we do? • Genetic Counseling• Prenatal Tests• Alpha-fetaprotein (AFP)• Ultrasound• Amniocentisis

Environmental Risks• Medicines, OTC and prescribed• Can cause deformities, mental retardation• Caffeine• Increased risk of miscarriage and low birth

weight• Nicotine (Cigarettes)• Low birth weight• Illegal drugs• Can pass on addiction to baby

Multiple Births

• Fraternal Twins• Mother releases two eggs and two different sperm fertilize• 3% (3 out of 100) of births in U.S. are fraternal• Fraternal twins

depends on family history, socio-economic status, mothers age (older moms are more likely)

Multiple Births

• Identical Twins– One sperm and one egg (zygote) splits – Always the same sex – .23% (23 out of 1000) are identical – Average number of identical twins is the same all over the world and

has not changed throughout history

• Triplets & More– Much less common and poses greater risk for mom and babies

Twins

Twins Trivia• Do identical twins have the same DNA and fingerprints?

• Identical twins, formed when one fertilized egg splits, are the only people in the world with identical DNA.

• Fraternal twins, on the other hand, are formed when two different eggs are fertilized.

• Genetically speaking, fraternal twins are no closer than normal siblings, sharing only about 50% of their genes.

• Although identical twins have the same genotype, or DNA, they have different phenotypes, meaning that the same DNA is expressed in different ways.

• Traits determined by phenotype, such as fingerprints and physical appearance, are the result of "the interaction of the individuals genes and the developmental environment in the uterus."

• Thus, a DNA test can't determine the difference between identical twins, while a simple fingerprint can

More No-No’s for Mama– You don’t have to write these!

– X Rays - Radiation can cause birth defects– Lead-based paint– Pesticides (used to kill bugs)– Mercury (found in some fish)– Unwashed Vegetables, Sushi, Cat Litter Box (toxoplasmosis)– Deli meats (listeria) – have to heat to steaming– Raw Eggs (cookie dough)– Soft cheeses (brie, feta, gorgonzola, queso blanco and fresco) – Amusement park rides– Jacuzzi’s and hot tubs– Extreme sports.

Consider this…

• Miranda suspected that she might be pregnant so she took a home pregnancy test, which confirmed that she was. A friend has told her to see a doctor, but Miranda says that she can’t afford it now.

• Is her response appropriate? Why or why not? • Inappropriate• Pregnant women should have prenatal care all

through their pregnancy for their health and that oftheir babies

Consider this…

• Alberto and Diane, parents of a healthy eight-year old, want another child. There is a history of birth defects in Diane’s family. They are going to visit with a genetic counselor.

• Is their response appropriate? Why or why not?

Consider this…

• Amy is a healthy twenty-three-year-old. She has just found out she’s pregnant. Her best friend’s baby was born with spina bifida. Amy is afraid that her child may be born with some birth defects and requests having special prenatal tests.

• Is her response appropriate? Why or why not?

Consider this…

• Chantal and her husband Charles want to have a baby. Since they made this decision, they both have quit smoking.

• Is their response appropriate? Why or why not?