Chapter 3: Pregnancy

• Period of the Zygote: conception to implantation
• Period of the embryo from week 3 to week 8, cell division, germ layers and little organs
• period of the fetus: Week 9 to birth
• Amnion: the closes membrane to the fetus
• Chorion: the outermost layer of the membrane that interacts with the mothers uterine wall
• Placenta: another layer of protection for the fetus, it also filters out waste and feeds the baby
• During the period of the Embryo, three cell layers are formed:

  • Ectoderm
  • Mesoderm
  • Endoderm
• Ectoderm: outside things, and neural tube
• Mesoderm: will become muscles, bones, and circulatory
• Endoderm: Becomes the internal organs
• Within the second month limbs, gonads, and a vague skeleton will form
• Third month: now the baby is considered a Fetus, and can swallow and can move
• In months 4-6, more motor skills are developing, the baby is covered in lanugo (small hair) and vernix (like lotion for the skin)
• In months 7-9, organs finish developing, gain a lot of weight and spin around with their head facing down
• Age of Viability is the survival outside the uterus. Usually between 22 to 28 weeks
• Teratogen: environmental agents that can cause harm to the fetus
• Environmental hazards: pollutions within the enviroment
• Maternal characteristics: nutrition, wellbeing, and age
• Each structure of the Fetus has a 'sensitive' period when it is most sensitive to damage from teratogens
• Rubella: Blindness, deafness, abnormality, and intellect disability
• Toxoplasmosis: brain damage and miscarriage
• Syphilis: Dangerous after 18th weeks, and damages the eye, ear, bones, heart, and brain damage. Miscarriage
• Herpes: causes death. blindness, brain damage, and neurological disorders
• HIV/AIDS: low birth rate, impaired early growth, immune system issues, and cognitive development
• Thalidomide: birth defects in their limbs, eyes, ears, and heart
• Diethylstilbestrol (DES), Seems to effect nothing till early adulthood
• Fetal Alcohol Syndrome: caused by heavy drinking in pregnancy: Causing hyperactivity, facial malformation, and other problems
• Fetal Alcohol effects: moderate 'social' drinking: poor motor skills, and attention problems
• Smoking: low birth weight and cleft palate and/or cleft lip, risk of miscarriage and SIDS
• SIDS: Sudden infant death syndrome
• Radiation: can cause deformities, death and intellectual disabilities
• Chemical and pollutants, causes deformities and disabilities
• Stress can cause issues for the fetus, due to coping mechanisms, and leads to higher birth complications due to low weight