pregnancy

• Pregnancy


  Events that occur from the time of fertilization (conception) until the infant is born

  
• Conceptus


  The pregnant woman's developing offspring

  
• Gestation period


  The time during which development occurs

  
• Embryo


  The conceptus from fertilization through week 8

  
• Fetus


  The conceptus from week 9 through birth

  
• Infant


  The conceptus at birth
• Accomplishing Fertilization


  1. Sperm transport and capacitation

  2. Acrosomal reaction and sperm penetration

  3. Blocks to polyspermy

  4. Completion of meiosis II and fertilization

  
• Zygote to Blastocyst Implantation

  1. Cleavage

  2. Blastocyst formation

  3. Implantation
• Placentation


  The formation of a placenta, a temporary organ that originates from both embryonic and maternal (endometrial) tissues

  
• Roles of the extraembryonic membranes

  • Amnion
  • Yolk sac
  • Allantois
  • Chorion
• Gastrulation: Germ Layer Formation


  Cellular migrations transform the inner cell mass into a three-layered embryo (gastrula) containing ectoderm, mesoderm, and endoderm

  
• Organogenesis: Differentiation of the Germ Layers

  1. Ectoderm forms nervous system and epidermis

  2. Endoderm forms digestive and respiratory systems

  3. Mesoderm forms all other organ systems and tissues
• Fetal development


  Rapid growth of body structures established in the embryo, with cells differentiating into specific cell types and completing fine details of body structure

  
• Effects of pregnancy on the mother

  • Anatomical changes
  • Metabolic changes
  • Physiological changes
• Anatomical changes


  • Reproductive organs become vascular and engorged
  • Vagina develops purplish hue
  • Breasts engorge and areolae darken
  • Uterus enlarges and pushes into abdominal cavity
• Metabolic changes


  • Placental hormones stimulate maturation of breasts for lactation
  • Maternal cells metabolize more fatty acids and less glucose
  • Increased maternal metabolism
• Physiological changes


  • Gastrointestinal system: nausea, constipation
  • Urinary system: increased urine production
  • Respiratory system: nasal congestion
  • Cardiovascular system: increased blood volume
• Parturition (Birth)


  1. Initiation of labor

  2. Dilation stage

  3. Expulsion stage

  4. Placental stage
• Adjustments of the infant to extrauterine life

  • Taking the first breath and transition
  • Occlusion of special fetal blood vessels and vascular shunts

  
• Lactation


  Breast milk production and release in response to suckling
• Breast milk advantages
• Clinical terms


  • Ectopic pregnancy
  • Dystocia
  • Breech presentation
  • Premature infant
  • Neonatal period
  • Physiological jaundice
• Clinical applications


  • Obstetrics
  • Prenatal development: first trimester, second trimester, third trimester
• During labor, contractions push the baby through the birth canal until it emerges from the vagina.
• The placenta is the organ that connects the mother to the fetus, providing nutrients and oxygen.
• After delivery, the umbilical cord is cut and the newborn is placed on the mother's chest to begin breastfeeding.
• Postpartum care involves monitoring the health of both the mother and the newborn.
• After delivery, the mother's uterus contracts to stop bleeding and return to its normal size.
• The placenta is expelled shortly afterward.
• After childbirth, the uterus contracts to expel the placenta (afterbirth).
• Maternal mortality refers to deaths related to complications during pregnancy or childbirth.