Pregnancy & Early Development Chapter 18 (pp. 443-450) Objectives: Describe how a human life begins Summarize how a baby develops during the three trimesters of pregnancy Identify five things a couple can do to stay healthy before and during pregnancy Summarize four problems that can occur during pregnancy Describe the stages of childbirth List three changes that occur during early child development

Do Now Why do you think genes are so important in the development of a fetus? What factors should a couple consider before they decide to have children?

Fertilization (conception) The joining of the sperm and egg in the fallopian tube

Zygote A one-celled fertilized egg Image (2h after fertilization)

Blastocyst The dividing mass of cells of the fertilized egg before implantation

Implantation The fertilized egg attaches itself to the uterus

Embryo A developing human from fertilization through the first 8 weeks of development In the seventh week, the embryo has both male and female primordial ducts x chromosome = female structures y chromosome = male organs (hormonal switch happens)

Placenta Mother’s Circulation Oxygen Drugs, Alcohol Nutrients Immunities Viruses Hormones Fetus’ Circulation Wastes Carbon Dioxide An organ that will form during pregnancy to nourish the developing embryo and fetus It comes out after birth http://www.alibaba.com/catalog/11026602/Placenta_Cream.html

Umbilical Cord Anything in the mother’s blood can enter the baby’s blood through the umbilical cord, by way of the placenta A cord that connects the developing baby to the placenta

Amniotic Sac A sac filled with fluid (Amniotic Fluid) which protects the baby during pregnancy

Trimesters of Pregnancy

Stages of Development Click on the following links to learn about fetal development: http://www.epigee.org/fetal.html http://www.nlm.nih.gov/medlineplus/ency/article/002398.htm

First Trimester (months 1-3) Fourth week: heart starts beating Arm and leg buds appear Eyes and brain begin to develop Size of a BB pellet

Second Trimester (months 4-6) The mother can feel the fetus move or “kick” Reproductive organs can be recognized as male or female Fetus can hear and recognize voices Hair forms on the body Head and facial features become apparent Fingers and toes grow nails

Third Trimester (months 7-9) Fetus gains most of its weight Brain develops further All other organs are almost complete Fetus can grasp with his or her hands Fetus’ nervous system will continue to develop after birth

Keeping Healthy Before and During Pregnancy Avoid alcohol and other drugs, and exposure to cigarette smoke Maintain a nutritious diet and eat regular meals Take prenatal vitamins Get regular, moderate levels of exercise Have regular checkups with a healthcare provider

Problems During Pregnancy Fetal alcohol syndrome (FAS) http://www.kidshealth.org/parent/medical/brain/fas.html Miscarriage (death before 20th week) Ectopic pregnancy http://www.kidshealth.org/parent/pregnancy_newborn/pregnancy/ectopic.html Toxemia http://familydoctor.org/online/famdocen/home/women/pregnancy/complications/064.html Gestational diabetes http://www.kidshealth.org/parent/question/infants/gestational_diabetes.html Rh incompatibility http://www.kidshealth.org/parent/pregnancy_newborn/pregnancy/rh.html Premature birth (delivery before 38th week)

Ectopic Pregnancy When a fertilized egg implants anywhere but in the uterus, usually in the fallopian tube This is dangerous and must be removed

Miscarriage Also known as a Spontaneous Abortion When a pregnancy will end by itself, usually during the first three months

Abortion When a pregnancy is terminated on purpose

1. Labor (dilation) 2. Expulsion 3. Afterbirth (placental) Childbirth 1. Labor (dilation) 2. Expulsion 3. Afterbirth (placental)

Labor Begins with contractions and ends when the cervix is completely dilated The longest stage of childbirth

Cervix dilating 0-10 cm

Cervix fully dilated @ 10 cm

Head appears after full dilation of cervix

Expulsion Passage of the baby through the birth canal The baby is “expelled” Ends when the umbilical cord is cut

Afterbirth Passage A few minutes after the umbilical cord is cut, the mother delivers the placenta and the rest of the umbilical cord

Episiotomy An incision made in the skin below the vagina to facilitate the passage of the baby through the vagina

Breech Birth When a baby comes out anyway other than head first, usually feet first

Caesarian Section The surgical removal of the baby through the abdomen Video: What to expect with a caesarian delivery http://mayoclinic.com/health/c-section/MM00531

Multiple Births Identical Twins Fraternal Twins Triplets ETC.

Identical Twins Fertilized egg splits They will share one placenta They will always be the same sex and are “identical”

Fraternal Twins Two separate eggs are fertilized by two separate sperm They will have their own placenta They are not “Identical”

Epidural Anesthesia Anesthesia given to a woman in her back for pain relief of labor and delivery. Woman does not feel pain, but she and the baby are not drugged.

Closure Describe the importance of prenatal care for keeping healthy before and during pregnancy.

Works Cited Textbook: Lifetime Health (2004) Fetal Development Overview at http://www.w-cpc.org/fetal.html Mayo Foundation for Education research athttp://www.mayohealth.org/mayo/baby/htm/ww5r450.html www. Google images http://mayoclinic.com/health/prenatal-care/PR00112