Prenatal Development

Placenta

Provides oxygen and nutrients, removes waste, produces some hormones

Think of it as the "life-support system" for the fetus

Amniotic fluid

Cushions the baby and regulates temperature

Protects against infection, acts like a shock absorber

Umbilical cord

Connects fetus to placenta

Transports nutrients, oxygen, and waste

Think: highway from placenta to baby

Amniotic sac

Holds amniotic fluid, surrounds fetus

Think: bubble of protection

If the question asks "provide nutrients/oxygen," think...

Placenta

If the question asks "cushions," think...

Amniotic fluid

Zygote

Fertilized egg

0-2 weeks

Embryo

Weeks 2-8

Major organs begin to form

Fetus

Weeks 9-birth

Organ growth and maturation

What's the first organ to function?

The heart

Beats around week 3-4

What is the critical period?

The first trimester

Major organs are vulnerable

What organs develop later?

Lungs, liver, and brain

Quickening

Usually in the second trimester

First noticeable fetal movment

Full-term pregnancy

37-42 weeks

Typically 40 weeks

Premature birth

Before 37 weeks

Post-term birth

After 42 weeks

First trimester

Organs developing

Second trimester

Growth and movement

Third trimester

Weight gain and preparation for birth

Folic acid

Prevents neural tube defects (spina bifida)

Critical in first trimester

Iron

Prevents anemia

For both mom and baby

Calcium

Supports bone development

Works well with vitamin D

Vitamin D

Helps calcium absorption

Sunlight and supplements

What's the recommended weight gain during pregnancy?

25-35 pounds

Progesterone

Maintains uterine lining

Low: miscarriage risk

Estrogen

Supports development and growth of the uterus and breasts (thickening of uterus and formation of breast tissue)

Imbalance: complications

Oxytocin

Triggers labor

Morning sickness

Caused by hormonal changes, especially hCG

hCG

Early pregnancy hormone

Causes morning sickness

Ovulation

Release of mature egg from ovary (mid-cycle)

Fertilization

Occurs in the fallopian tube

Implantation

Embryo attaches to the uterine lining

What's the order of events for pre-pregnancy and pregnancy?

Ovulation --> fertilization --> implantation --> embryonic --> fetal stages

Amniocentesis

Tests fetal DNA for genetic disorders

Ultrasound

Gives an image of the baby, checks growth

growth and development check

MRI/X-ray

Medical imaging, not for genetic testing

Week 4

Cluster of cells

Week 8

Embryo starts looking like a baby; features form

Week 12

Fetus continues to grow; features established

Birth

Fully developed baby