Flashcards in Third Month to Birth: The Fetus Deck (10):
When does the greatest length increase occur?
months 3, 4, and 5
When does the greatest weight increase occur?
months 8 and 9
Length of pregnancy
38 weeks (266 days) after fertilization or 40 weeks after the last menstrual period
When does the external genitalia develop?
week 12 (the sex of the fetus can be determined by ultrasound)
Highlights of 13 to 16 weeks
growth is very rapid here, limb movements are more coordinated, face becomes more human-looking, by 16 weeks the ovaries are differentiated and contain primordial follicles that have oogonia
Highlights of 17 to 20 weeks
growth slows down, movements are felt by mother, brown fat forms, testes begin to descend
Highlights of 21 to 25 weeks
substantial weight gain, secretory epithelial cells in the lung have begun to secrete surfactant, sucking movements and can react to sounds, respiratory system immature
Highlights of 26 to 29 weeks
lungs have developed sufficiently for gas exchange, CNS has matured where it can direct rhythmic breathing and control body temp., formation of red blood cells moves to bone marrow
Highlights of 30 to 34 weeks
pupillary light reflex of the eyes, 32 weeks and older typically survive if born