| Chapter 3 First trimester: Implantation of zygote in uterus about a week after fertilization Rapid cell division and specialization Placenta formed between zygote and uterus: allows exhange of nutrients, oxygen, and wastes without blood mixing Called embryo after two weeks Morning sickness Called fetus after 8 weeks Second trimester: Morning sickness usually disappears Increase in appetite => recommended gain weight of 25 to 30 pounds. Can determine sex by 13th week Major brain structures develop Teratogens Medication, caffeine, smoking, alcohol, stress, depression, radiations, pollution => have proper diet, lifestyle, support, light exercise Age of viability around the 24th week |
 |