From Fetus to Baby!

Signs of pregnancya. Missing menstrual periodb. Pregnancy tests

a. these tests detect the presence of hCG (human chorionic gonadotrophin) in the urine

b. hCG is produced by the developing embryo and is present is a woman’s urine only when she is pregnant

Embryo Development & Stages of Pregnancy

First Trimester: (week 1- week 13)

Week 1- 7: “Embryo” Week 8: “Fetus” Week 12:

Sex of fetus can be determined

The fetus can move

Second Trimester: (week 14- week 26) Week 20:

Fetus can hear sounds Can suck it’s thumb Hair begins to grow Use it’s digestive system

by swallowing amniotic fluid

Week 24: Mother can feel the baby

moving (kicks from the legs)

Third Trimester: (week 27 – week 40)

Rapid development of the fetus which requires a large quantity of nutrients from the mother it’s crucial for the mother to eat a healthy diet

Week 28: Fetus can open it’s eyes

Week 32: fetus settles into a head down position in preparation for birth

Week 36: Recognizes mother’s voice

Embryo development & stages of pregnancy

Functions of the placenta, umbilical cord A. Placenta

Membrane that forms between the mother’s uterus and the developing embryo

Allows for exchanges of nutrients and oxygen between mother and embryo (it serves as a filter)

N.B. Mother’s blood does not enter the embryoB. Umbilical cord

connects fetus to the placenta, cut at birth

Functions of amniotic fluid

In the uterus, the fetus is suspended in a fluid called amniotic fluid

This fluid has 3 functions To protect the fetus from injury To keep body temperature of the fetus constant To protect the fetus against dehydration

Identical and fraternal twins

a. Identical twins (30% of the time) From a single egg and sperm Great deal of resemblance

Same chromosomes Same sex Same blood type

b. Fraternal twins (70% of the time) Two ova, two sperms Little resemblance

Important factors to consider during pregnancy

A. NutritionB. Physical exerciseC. Tobacco

(harmful chemicals pass through the placenta to the fetus)

D. Alcohol Fetal alcohol syndrome is characterized by growth,

mental, and physical birth defects associated with the mother's high levels of alcohol use during pregnancy

Alcohol ingested by a pregnant woman easily passes across the placental barrier to the fetus

Process of birth

Process of birth

A. Signs of the onset of laboura. Uterine contractions are triggered to begin by the

hormone oxytocin secreted by the pituitary gland Initially are irregular but they become:

More frequent Stronger Regular

b. Rupturing of the amniotic sac (“water breaks”) As result of the contractions… Rupture the membrane surrounding the fetus Cause the amniotic fluid to flow out of the body

It lubricates the baby’s passage out of the body

Process of birthB. 4 Stages of labour (8-20 hours)

a. Dilatation of the cervix (2-20 hours) The cervix is the lower end of the uterus It must open to allow the mature fetus to leave the

mother’s body Opens wider over time and with each contraction

b. Engagement of the baby’s head in the vagina (30 min – 2 hours)

The baby moves through the cervix into the vagina The baby’s head rotates to help it’s body pass out of

the vagina more easily

Process of birth

B. 4 Stages of labourc. Expulsion of the baby (5 to 60 min)

Physician holds the baby’s head and gently eases the shoulders, trunk, and finally the lower limbs out of the mother’s body

Baby’s head might be slightly deformedd. Expulsion of the placenta (10-15 min after birth)

Once the baby is born, the contractions continue and cause the placenta to detach and be expelled

Process of birth

Different types of delivery Natural childbirth: with the active participation of the

mother, no anesthetic Caesarean

delivery of a baby through an abdominal incision performed when a vaginal birth is not possible or is not safe for

the mother or child C-sections have become fairly common

Induced labour: stimulated by the injection of a hormone Administering of a local anesthetic

Epidural (injection into the spine)

Human Reproduction Test Female and male anatomy

Know how to label a diagram (* you will not be given a word bank!)

Know functions of all organs Puberty and hormones Menstrual Cycle Stages of development (zygote embryo

fetus Baby!) Process of birth