Fetal Lifespan

These flashcards cover key terminology, milestones, and medical concepts related to embryogenesis, fetal development, and pregnancy complications based on the lecture notes.

Gestation

The timeframe between the fertilization of the egg and the eventual birth, typically lasting about $40$ weeks and divided into three trimesters.

Gestational age

The time calculated from the first day of the client's last menstrual period ($LMP$), described in weeks to estimate the development stage of the fetus.

Pre-embryonic period

The interval including the $2$ weeks before fertilization and continuing until the zygote develops at the end of week $2$.

Embryonic period

A critical window for fetal development starting at week $3$ of gestation and lasting until the end of the $10$-week mark, during which all major organ systems form.

Fetal period

Begins at week $11$ and continues until birth, characterized by the maturation of organ systems and the fetal growth spurt.

Blastocyst stage

The developmental stage reached by the end of day $5$ post-fertilization where cellular differentiation begins.

Zona pellucida

A protective layer surrounding the blastocyst that prevents it from contacting or implanting into the fallopian tube lining.

Amnion

The membrane that produces amniotic fluid to cushion the fetus and maintain a stable temperature.

Chorion

A membrane that contributes to the formation of the placenta and facilitates nutrient and oxygen exchange.

Allantois

The membrane responsible for the removal of nitrogenous waste products and contributing to the umbilical cord structure.

Yolk Sac

A structure providing nutrition and gas exchange before the placenta develops, instrumental in forming the other three membranes.

Amniotic Fluid Index ($AFI$)

A measurement of amniotic fluid volume; high levels indicate polyhydramnios and low levels indicate oligohydramnios.

Amniocentesis

A procedure to sample amniotic fluid for genetic testing that carries a 0.5\text{%} to 1.0\text{%} risk of pregnancy loss and infection.

Placenta previa

A complication where the placenta implants in the lower uterine segment over or near the cervix, potentially necessitating a cesarean birth.

Wharton’s jelly

Embryonic connective tissue that protects the umbilical cord's vessels and ensures cord integrity.

Umbilical Vein

A vessel within the cord that carries oxygenated blood from the mother/placenta to the fetus.

Umbilical Arteries

Two vessels within the cord that carry deoxygenated blood and waste from the fetus to the placenta.

Ductus Venosus

A shunt in the liver that transports oxygenated blood from the placenta to the inferior vena cava, bypassing the non-functional fetal liver.

Foramen Ovale

An opening between the right and left atria that allows blood to bypass the non-functioning pulmonary system before closing after birth.

Ductus Arteriosus

A structure between the pulmonary artery and the aorta that allows blood to bypass the pulmonary system, constricting and closing after birth.

Pulmonary surfactant

A substance produced by the lungs by week $32$ to decrease surface tension; it is insufficient to prevent atelectasis until week $34$.

Neural tube closure

A critical neurological development occurring during week $4$ of gestation.

Meconium

Visible in the intestinal tract by week $22$, indicating functioning gastrointestinal processes.

Lanugo

Fine hair that appears on the fetus around weeks $15$ to $18$ to provide warmth.

Vernix caseosa

A thick white substance covering the fetus during weeks $27$ to $30$ for protection and hydration.

Spontaneous Abortion

Pregnancy loss before viability, usually defined as occurring around $20$ weeks.

Threatened Abortion

A type of loss characterized by mild/moderate cramping and bleeding where the cervix is closed and the pregnancy remains viable in 50\text{%} of cases.

Missed Abortion

A condition where the fetus has died but remains in the uterus without contractions or bleeding.

$Rho(D)$-immune globulin ($RhoGAM$)

Medication administered to Rh-negative clients within $72$ hours of a pregnancy loss to prevent alloimmunization.

Mifepristone

A synthetic steroid and progesterone receptor antagonist used to prevent pregnancy continuation during medication abortion.

Misoprostol

A synthetic prostaglandin $E_1$ analog used to induce uterine contractions and cervical dilation.

Intrauterine Fetal Demise ($IUFD$)

The medical term for fetal death occurring at or beyond viability ($20$ weeks) or a weight of $350/500g$.