REPRODUCTION/ PREGNANCY

Fertilization The sperm fertilizes the egg: –In the fallopian tubes –1 sperm is all it takes (a chemical change prevents other sperm from entering the egg) –They combine to form 1 cell (zygote) Sperm can live in a woman’s uterus for 3 – 5 days

Fertilized Egg Divides The zygote travels down the fallopian tubes toward the uterus (takes 3-5 days) –Divides into 2 cells, then 4, then into a ball of many cells

Embryo Implants in the Uterus Embryo – a developing human from fertilization to the 1 st 8 weeks Implantation – the embryo becomes embedded in the uterine wall –Once this happens the female is considered to be pregnant

Placenta Supports the Baby Placenta – a blood vessel-rich organ that forms in a mother’s uterus –Provides nutrients and oxygen to and removes waste from a developing human –The babies growth is completely dependent on this

Baby’s Development – 1 st Trimester The 1 st 3 months –Major time for growth and change –The embryo starts growing rapidly –By the 4 th week the heart starts beating, arm and legs buds appear, and the eyes and brain begin to develop –Embryo the size of a BB pellet ( ¼ inch long) –Umbilical cord is developed

1 st Trimester

Baby’s Development – 1 st Trimester The start of the 9 th week until the end of pregnancy the developing human is called a fetus –Brainwaves can be detected –Muscle movement begins –Bones are developing

Baby’s Development – 2 nd trimester Months 4 – 6 –Organ systems continue to develop –Mother can start feeling the fetus move or “kick” –Reproductive organs can be recognized –The fetus can hear and recognize voices –Hair forms on the body

Baby’s Development – 2 nd trimester Head and facial features develop Fingers and toes start to grow nails A fetus born prematurely at the end of this trimester may be able to survive with medical assistance and support

2 nd trimester

Baby’s Development – 3 rd trimester Months 7 – 9 –When the fetus gains most of its weight –By 8 months most fetuses are 20 inches long –Brain develops further –All organs are almost complete

Baby’s Development – 3 rd trimester The fetus can grasp with their hands Skin starts becoming smooth The nervous system will continue to develop after birth

3 rd trimester

Keeping Healthy During Pregnancy Avoid alcohol and other drugs Take prenatal vitamins Get regular, moderate levels of exercise Have all medical conditions evaluated by a doctor

Problems During Pregnancy Miscarriage –Death of a fetus from natural complications before the 20 th week of pregnancy Vaginal bleeding or pregnancy tissue expelled from uterus

Problems During Pregnancy Ectopic Pregnancy –Implantation of the fertilized egg in the fallopian tube Abdominal pain early in the pregnancy, weakness, fatigue

Problems During Pregnancy Toxemia –Medical problems with unknown cause, but common in pregnant teens; may be related to the placenta or hormones Swelling of face and ankles, high blood pressure, and protein in urine of mother; convulsions if severe

Problems During Pregnancy Gestational Diabetes –Diabetes during pregnancy High blood sugar levels in the mother –Change of diet, medication, and, in some cases early delivery of baby