Prenatal Development Vocabulary Flashcards

Prenatal development

Development of the baby before birth; occurs in three stages: zygote, embryo, and fetus.

Zygote

Fertilized egg that begins dividing as it travels to the uterus; implants to become the embryo.

Embryo

Developing organism from conception through about the end of the 8th week (Months 1–2 in the notes).

Fetus

Developing baby from about Month 3 (week 9 onward) until birth; internal organs are present but not all function yet.

Conception

Moment when a sperm fertilizes an egg; typically occurs if sperm reaches the egg within about 24 hours.

Ovum

The female egg released monthly during ovulation.

Fallopian tube

The passage from ovary to uterus where fertilization often occurs.

Blastocyst

A ball of cells formed when the zygote divides; it travels to and implants in the uterus.

Implantation

The blastocyst attaches to the uterine wall and begins embryo development.

Monozygotic twins

Identical twins; arise when one fertilized egg splits into two.

Dizygotic twins

Fraternal twins; arise from two separate fertilized eggs.

Placenta

Tissue that connects the baby to the mother’s uterus; provides nutrients and removes wastes.

Umbilical cord

Tube connecting the baby to the placenta; carries nutrients/oxygen and wastes.

Amniotic fluid

Fluid surrounding the developing baby in the amniotic sac for protection and movement.

Amniotic sac

Membrane surrounding the fetus that contains the amniotic fluid.

Lanugo

Fine, soft downy hair covering the fetus (common in the fetal period).

Vernix

Protective white waxy coating on the baby’s skin that forms before birth.

Teratogen

Any agent that can cause birth defects or negatively alter fetal development.

Toxoplasmosis

Parasite from cats (and some livestock) that can affect a pregnant person and fetus.

Premature birth

Birth occurring before 37 weeks of gestation.

Average pregnancy length

Typically about 40 weeks from conception to birth.

Missed menstrual period

One early sign of pregnancy when a monthly period is absent.

Morning sickness

Nausea and sometimes vomiting experienced in early pregnancy.

Frequent urination

Increased urination common in pregnancy due to hormonal changes.

Cravings

Strong desires for particular foods during pregnancy.

Breast enlargement

Breasts enlarge in preparation for milk production during pregnancy.

Fatigue

Feeling of extreme tiredness common in pregnancy.

Urine pregnancy test

Medical test used to determine if a woman is pregnant.

Month 1 events

Fertilized egg reaches the uterus; cell division begins; heart starts beating; arm/leg buds begin to form.

Month 2 events

Embryo ~1/4–1/2 inch; all major organs develop; placenta and umbilical cord form; face/limbs take shape.

Month 3 events

Fetus ~2.9 inches; nostrils, mouth, lips, teeth buds, and eyelids form; fingers and toes develop; organs present but not functional; gender identifiable.

Second trimester

Period characterized by skin changes and mood shifts; mother feels fetal movements.

Month 4 events

Fetus ~5 inches; lanugo covers skin; heartbeat audible; first kicks; sucking/swallowing/hiccup.

Month 5 events

Fetus ~10 inches; vernix forms on skin; hair and eyebrows appear; organs mature; eyes can open.

Month 6 events

Fetus ~12–13 inches; 1.5 pounds; lungs practice breathing; fat deposits; fingerprints form; possible hearing.

Third trimester

Final stage; abdomen enlarges, fatigue and discomfort may occur, movement often continues and mothers monitor fetal activity.

Month 7 events

Fetus ~15 inches; 2–2.5 pounds; senses active; may turn toward bright light.

Month 8 events

Fetus ~18 inches; 4–5 pounds; fat layers form; head-down position common; can react to noises.

Month 9 events

Fetus ~19–20 inches; 6–9 pounds; skin smooth from fat; movement slows; antibodies transferred from mother.

Weight gain during pregnancy

Total gain typically about 25–30 pounds to support baby, placenta, uterus, fluids, and maternal stores.

Baby weight

Approximately 7.5 pounds of the total pregnancy weight is the baby.

Placenta weight

Approximately 1.5 pounds of the total weight is the placenta.

Uterus weight

Approximately 2 pounds of the total weight is the uterus.

Amniotic fluid weight

Approximately 1.5 pounds of the total weight is the amniotic fluid.

Extra blood and water weight

Approximately 4.5 pounds of the total weight is extra maternal blood and water.

Breast tissue weight

Approximately 3 pounds of the total weight is breast tissue.

Maternal protein stores weight

Approximately 4 pounds of the total weight are maternal protein stores.

Danger signals

Warnings to seek medical care immediately: vaginal bleeding, severe pain/cramps, fluid loss, dizziness, visual changes, persistent nausea/vomiting, sudden swelling, headache, painful urination, fever, or vaginal discharge.