Pregnancy

Fertilization

The process of the egg and sperm uniting, typically occurring in the fallopian tubes.

Blastocyst

A stage of embryonic development consisting of 200-300 cells, formed about 5 days after fertilization.

Placenta

An organ connecting the mother and fetus, facilitating nutrient and gas exchange; forms from the trophoblast.

Umbilical Vein

Carries oxygenated, nutrient-rich blood from the placenta to the fetus.

Trimesters

Pregnancy divided into three-month periods; 1st (fertilization to 12 weeks), 2nd (13 to 24 weeks), 3rd (25 weeks to birth).

hCG

Human chorionic gonadotropin hormone sustaining pregnancy by maintaining the corpus luteum and secreting progesterone.

Maternal Adaptations

Changes in maternal organs and systems to accommodate fetal growth, including increased blood volume and cardiac output.

Fetal Circulation

Unique circulation in the fetus with shunts like ductus venosus, foramen ovale, and ductus arteriosus, which close or become ligaments after birth.

Cyanosis

Bluish discoloration due to mixing of deoxygenated and oxygenated blood, often caused by a persistent foramen ovale post-birth.