Prenatal Development and Birth Three PreNatal Periods A

Pre-natal Development and Birth

Three Pre-Natal Periods A. Germinal Period (conception to implantation… 10 – 14 days) 1. Zygote – Single, fertilized cell (36 hours) 2. Blastocyst – sperhical mass of cells 3. Differentiation Occurs – cells change into distinct layers • Ectoderm – Skin and central nervous system • Endoderm – Lower layer (most organs) • Mesoderm – Middle layer (skeleton, muscles, circulatory system)

B. Embrionic Period (implantation to 8 weeks) 1. 1 st Month – Neural tube forms (brain & spinal chord) • Cephalocaudal Development – growth works from the head out to extremeties • By end of 1 st month – eyes, ears, nose, mouth, and budding appendages begin to form • Umbilical cord - 2 arteries & 1 vein 2. 2 nd Month – appendages become more distinct • By 8 weeks, 1” long and 1/30 of an ounce • Intestinal tract appears

C. Fetal Period (2 -9 months) 1. 3 rd Month – muscles develop and start working • Cartilage turns to bone • Sex organs develop 2. 2 nd Trimester (4 -6 months) • Hair grows, heartbeat, brain growth is rapid 3. 3 rd Trimester (7 -9 months) • Heart & lungs grow stronger, brain still grows quickly, fat layer developes (gains ~5 ½ lbs. )

Damaging Effects A. Teratogens (from the Greek tera, meaning “monster”) • Any agent (radiation, drug, etc) capable of altering fetal development in ways that cause birth defects. • Ex: In the late 1950’s many women took thalidomide early in pregnancy to prevent morning sickness and insomnia. Babies born to these mothers had stumps for arms and legs.

Damaging Effects B. HIV/AIDS • 20 percent of infants born to women infected with HIV become infected with the virus. • There are 3 ways a mother with HIV can infect her offspring: 1. During Pregnancy – through the placenta 2. During Delivery – through contact with maternal blood and other fluids 3. After Birth – through nursing

Damaging Effects C. Fetal Alcohol Syndrome • Definition: a cluster or abnormalities that occur in children born to mothers who are heavy drinkers. • Symptoms include a small head and defective limbs, face, and heart.

Damaging Effects D. Smoking and Pregnancy • Fetal and neonatal deaths, and preterm birth, are higher among smoking mothers. • Urine samples of newborns born to smoking mothers show substantial amounts of carcinogens • Prenatal exposure to cigarette smoking is correlated to poorer language and cognitive skills.

The Newborn Baby Immediately after birth, the Hospital staff will conduct baby’s first checkup: • Clear airways by suctioning mouth & nose • Clamp and cut umbilical cord • Assign an Apgar Score an 1 and 5 minutes • Apply antibiotic to baby’s eyes • Weigh baby (average is 7 ½ lbs. ) • Measure length (avg is 20”) • Measure head circumference (avg is 13. 8”. . normal is 12. 9 to 14. 7) • Count fingers, toes, and look for any deformity • Hearing screening

The Newborn Baby Blood Tests: 1. Hypothyroidism: thyroid gland isn’t working properly Symptoms: • Dull look, puffy face, thick tongue that sticks out • Choking episodes, constipation, jaundice, lack of muscle tone, poor feeding, sleepiness

The Newborn Baby Blood Tests cont. 2. PKU: rare condition in which a baby is born without the ability to properly break down an amino acid called phenylalanine.

The Newborn Baby Symptoms of PKU: • Lighter skin, eyes, hair color than siblings • Delayed mental and social skills • Head size significantly below normal • Hyperactivity • Jerking of arms and legs • Mental retardation • Musty odor on breath, skin, and urine

The Newborn Baby Treatment of PKU: • Diet – • No milk, eggs, or other dairy • No meat • No nuts or seeds • No sweetener (aspartame) • Special Infant formula • Fish oil supplement • Iron supplement

The Newborn Baby Complications from PKU: If untreated: • Severe mental retardation from brain damage (usually by first birthday). If treated: • Normal functioning If treated, but diet not followed: • ADHD