Ch. dev. 1/23

Overview of the Lecture

• Focus on prenatal development with an overview of child development stages.

• The only lecture emphasizing a specific stage in child development.

Prenatal Development Stages

Major Stages

1. Germinal Stage

   • Lasts for about two weeks.

   • Begins after sperm fertilizes the ovum, forming a zygote.

   • Zygote divides and travels down the fallopian tube to implant in the uterus.

   • Only 25-50% of zygotes successfully implant.

   • Not typically detectable as pregnancy until after the germinal phase.

2. Embryonic Stage

   • Lasts from weeks 3 to 8.

   • Zygote becomes an embryo after implantation.

   • Formation of the placenta, which serves as the gateway for nutrients and oxygen from the mother.

   • Growth patterns: Cephalocaudal (head to toe) and Proximal Distal (inside out).

   • Major organs begin to develop.

3. Fetal Stage

   • Begins at week 9 and lasts until birth at around week 40.

   • Fetus develops further, gaining more recognizable features.

   • Key developments include:

     • 9 weeks: fetal stage begins

     • 12 weeks: sex organs differentiate

     • 20 weeks: fetus can hear

     • 24 weeks: lungs develop; age of viability

     • 28 weeks: rapid brain growth

     • 36 weeks: muscles fully developed

     • 40 weeks: considered full term

Importance of Brain Development

• All neurons are developed by 5 months in utero.

• Brain development crucial during prenatal stage as it influences learning and functioning.

Teratogens: Environmental Risks

• Definition: External factors that can negatively impact fetal development.

Types of Teratogens

1. Alcohol

   • Associated with fetal alcohol spectrum disorders (FASD).

   • Avoidance is strongly recommended during pregnancy.

2. Pollutants

   • Includes lead, pesticides, BPA, radiation, and mercury.

   • Common in older homes and certain environments.

   • Lead can cause significant developmental issues; avoid lead exposure.

3. Diseases and Viruses

   • STIs like gonorrhea, syphilis, chlamydia, and HIV can transfer from mother to child.

   • Rubella (German measles) also poses risks.

4. Tobacco and Illicit Drugs

   • Lead to pollutants and toxins affecting fetal health.

   • Consultation with medical professionals encouraged for prescription medications during pregnancy.

5. Parasites

   • E.g., Toxoplasmosis found in pets, particularly cats.

   • Pregnant women should avoid handling cat litter due to transmission risk.

Maternal and Paternal Factors

• Maternal Factors:

  • Risks increase with maternal age (over 35 years): fertility issues, genetic disorders, stillbirths, etc.

  • Gestational diabetes: treated through diet and monitoring; risk for premature birth.

• Paternal Factors:

  • Older fathers (over 40 years) may face risks of miscarriage, autism, birth defects due to chromosomal abnormalities.

Delivery Process

Stages of Vaginal Delivery

1. Dilation Stage

   • Cervix dilates to 10 centimeters.

   • Can last hours to days.

2. Birth Stage

   • Baby is delivered head first, followed by shoulders and body.

3. Afterbirth

   • Delivery of the placenta follows the birth of the baby.

Cesarean Section (C-Section)

• Reasons for C-sections include:

  • Baby's size, maternal health risks, signs of distress, or multiple pregnancies.

Induced Birth

• Induction may occur if pregnancy extends past due date or if health issues arise.