Summary of Pregnancy and Fetal Development

Ligaments and Uterus Support

  • Ligaments are crucial for supporting the uterus during pregnancy.

Key Terms in Embryonic Development

  • Zygote: Fertilized egg.

  • Embryo: Developed from the zygote.

  • Blastocyst: A stage after the embryo.

  • Fetus: Later stage of development.

Placenta Function

  • Develops at the site of implantation.

  • Temporary organ providing oxygen and nourishment to the fetus.

  • Important for determining delivery methods and fetal health.

Fetal Development Stages

  1. First Trimester (Weeks 1-12): Rapid changes, major organs developing.

  2. Second Trimester (Weeks 13-28): Continued development; heart beats and limbs form.

  3. Third Trimester (Weeks 29-40): Weight gain and preparation for life outside womb.

Fetal Circulation

  • Fetus relies on mother's body for oxygenation and filtration.

  • Important structures: Ductus arteriosus and foramen ovale bypass the liver and lungs.

Hormones of Pregnancy

  1. Progesterone: Maintains pregnancy, calms uterine muscles.

  2. Estrogen: Stimulates growth, improves placental blood flow.

  3. HCG: Detects pregnancy status.

  4. Human Placental Lactogen: Prepares for milk production.

  5. Relaxin: Causes relaxation of ligaments for birth preparation.

Umbilical Cord Details

  • Formed by week five, connects fetus to placenta.

  • Composed of two arteries and one vein (aka "AVA").

  • Wharton's jelly protects and supports blood vessels.

Amniotic Fluid

  • Cushions fetus, prevents compression of umbilical cord.

  • Average volume: 700-800 mL, important for fetal health analysis.

Multiple Pregnancies

  • Can be monozygotic (identical) or dizygotic (fraternal).

  • Risk factors include age, family history, and fertility treatments.

Teratogens and Risks

  • Teratogens can cause birth defects and should be avoided during pregnancy.

  • Risks associated with substances like alcohol, tobacco, caffeine, and illicit drugs.

Medication Use During Pregnancy

  • Minimize medication; nothing crosses placenta without risk.

  • Always consult healthcare provider for safe options.

Environmental Risks

  • Avoid chemicals, heavy metals, hot tubs, saunas, and certain foods that may harbor infections.

  • Stay cautious of exposure to infections (e.g., toxoplasmosis).