When Egg Meets Sperm…

Life Spans Unfertilized egg can only live for 24 hours Sperm usually live for 48 hours (can live up to 7 days) in a women’s body

Fertilization The fusion of a sperm and egg Millions of Sperm are released in the vagina move up uterus & to the fallopian tubes  if there is an egg, fertilization occurs ONLY 1 sperm can fertilize an egg! Once this occurs, a protective shield forms (fertilization envelope) around the egg Fertilized egg = Zygote

What’s Next? Zygote divides into many cells  moves into uterus Ball of cells = blastocyst Cells travel for 7-8 days Attach to uterine lining & continue developing Called implantation

The Pathway

Implantation Occurs when the embryo attaches to the wall of the uterus Some women can feel this occur (feel light cramps) Causes a hormone called hcG to be released Supports pregnancy what pregnancy tests use

After implantation: Pregnancy Membranes develop around the embryo to protect & nourish it = placenta

More on pregnancy… Umbilical cord: connects embryo to mom Transports oxygen & nutrients to embryo Removes waste products At 8 weeks, embryo is called a fetus Pregnancy lasts about 266 days 40 weeks or 9 months

Giving Birth Oxytocin (hormone) triggers uterine wall to contract Labor begins Cervix expands Baby starts to emerge, head first  cut cord Cord will dry up/fall off  becomes your belly button Placenta must be delivered after baby

Miscarriages Spontaneous end of a pregnancy Types: Causes: Occurs when a fetus can NOT survive out of the womb Types: Embryo stops growing very early  no fetus forms Fetal heartbeat has stopped  fetus has died Causes: Genetic Uterine abnormalities, hormonal abnormalities Reproductive tract infections Tissue rejection Risk Factors: diabetes, smoking, drugs, fertility issues, etc

Stillbirth Baby has died during delivery or prior to birth Causes: (many) Umbilical cord Diabetes Trauma Drugs, smoking Birth defects infections

Ectopic Pregnancies Implantation occurs outside the uterus in: In fallopian tube *most common 95%* Cervix Abdomen Ovary Pregnancy has to be terminated Symptoms similar to pregnancy Additional symptoms: bleeding, lower back pain, low blood pressure, dizziness, sharp stabbing pain in back/neck

Infertility Inability to conceive Options: Can be female or male Fertility drugs: side effects include multiples IVF (invitro fertilization): fertilization happens outside the body Very expensive, possible multiples Egg Donors/Sperm Donors Expensive, invasive for egg donors Would you want it? Adoption Can be expensive, heartbreaking, and joyful

Why do Birth Control Pills Work? Estrogen & progesterone pills  fool your body into thinking you are pregnant Hence, you don’t ovulate (or shouldn’t), FSH & LH stay low Effectiveness also depends on following directions