Mom and dad, empty pad, there’s time, prophylactic’s bad
Sperm are swimming, egg is going, fertilization

Week one, zygote there, dividing here, there, everywhere
Two, four, eight, sixteen, that’s the morula

Zona pellucida, shed from early blastocyst
Late blastocyst now, trophoblast and blastocoele

Trophoblast splits into inner cytotrophoblast
Synctiotrophoblast, outer shell, implanting


CHORUS
We didn’t stop the fetus
It keeps on developing, inside mom’s belly
We didn’t stop the fetus
Since we did create it, we are going to wait for it


Week two, synctiotrophoblast makes hCG
Corpus luteum continues the pregnancy

Embryonic disc formed, epiblast, hypoblast
Amnion, exocoelomic cavity

Week three, pretty long, gastrulation comes along
Ecto, meso, endo, trilaminar embryo

Primitive streak and node, neuralation, notochord
Neural plate forms neural groove, neural folds, then neural tube


Week three continuing, somites, coelem are forming
Early heart formation, chorionic villi

Now onto week four, closed the rostral neuropore
Otic pits, lens placodes, both limb buds are visible

Embryo c-shaped, rudimentary organ systems
Week five, not four, close the caudal neuropore

Weeks six through eight, digits start to separate
Ossification, intest’nal herniation


During weeks nine through twelve, intestines in the abdomen
Fetus doubles its size, begins forming the urine

Hematopoiesis, first the liver, then the spleen
Thirteen to sixteen, females have their ovaries

Seventeen through twenty, uterus, testes
Lanugo, quickening, vernix caseosa forms!


Twenty-one to twenty-five, fetus probably can survive
Weight gain, surfactant, fingernails are present

Twenty-six to thirty-four, white fat increases some more
CNS maturates, pupils constrict and di-alate

In weeks thirty-five and eight, towards light, orientates
Firm grasp, fetus plump, ultrasound, crown-to-rump

White fat, one-eighth of the total body weight
Growth slows, momma knows, parturition, here it goes!