Ob/Gyn Registry Review Flashcards

A vocabulary-style review of core concepts for the Ob/Gyn Registry, covering female pelvic anatomy, gynecological pathology, fetal development, and obstetrical complications.

Linea terminalis

An imaginary line extending from the pubic symphysis to the sacral prominence that separates the true pelvis from the false pelvis.

Levator ani and coccygeus

Hammock-shaped muscles that form the pelvic diaphragm, providing support to pelvic organs; weakening of these leads to uterine prolapse.

Obturator internus

A muscle of the true pelvis located lateral to the bladder.

Piriformis

A muscle of the true pelvis located posterolateral to the pelvic structures.

Broad ligament

A double fold of peritoneum extending from the lateral sides of the uterus to the pelvic walls; it is only visualized on sonography in the presence of pelvic ascites.

Space of Retzius

Also known as the retropubic space, it is located anterior to the bladder.

Pouch of Douglas

Also known as the posterior cul-de-sac or rectouterine pouch, it is located between the uterus and the rectum.

Internal iliac artery

Also known as the hypogastric artery, it is the vessel from which the uterine arteries originate.

Left ovarian vein

The longest pelvic vessel, which drains into the left renal vein instead of the IVC.

Neonatal uterus

A prominent uterus due to maternal hormone stimulation, characterized by an enlarged cervix with a $2:1$ ratio to the uterine body.

Anteflexion

A uterine position where the body of the uterus folds forward and comes in contact with the cervix.

Ampulla

The longest and most tortuous segment of the fallopian tube; it is the most common location for fertilization and ectopic pregnancies.

Follicle-stimulating hormone (FSH)

A hormone released by the pituitary gland that stimulates the development and maturation of ovarian follicles.

Luteinizing hormone (LH) surge

A peak in hormone levels that stimulates the rupture of the dominant follicle, resulting in ovulation.

Early proliferative phase

The endometrial phase immediately following menses where the endometrium is thin, echogenic, and measures no more than $4mm$.

Secretory phase

The endometrial phase where progesterone maintains thickness ($7-16mm$) to prepare for implantation; the endometrium appears thick and echogenic.

Gravida

A clinical term indicating the total number of pregnancies a woman has had.

Para

A clinical term indicating the number of pregnancies a woman has carried to term.

Mittelschmerz

A term meaning "middle pain," referring to pain experienced in the middle of the menstrual cycle near the time of ovulation.

Primary amenorrhea

The failure to reach menarche (first menses) by the age of $16$.

Septate uterus

The most common congenital uterine anomaly, characterized by two completely separate endometrial cavities and a concave fundal contour.

Hematometracolpos

The accumulation of blood within both the uterus and the vaginal canal, often caused by an imperforate hymen.

Adenomyosis

The invasion of endometrial tissue into the myometrium, often causing a heterogeneous, enlarged uterus and "linear striations."

Leiomyoma

Also known as a fibroid or myoma, it is a benign smooth muscle tumor stimulated by estrogen; it is the most common benign gynecological tumor.

Submucosal fibroid

A type of leiomyoma located adjacent to the endometrium that distorts the endometrial contour and is most likely to cause bleeding issues.

Endometrial hyperplasia

Abnormal thickening of the endometrium resulting from unopposed estrogen stimulation; it is a common cause of postmenopausal bleeding.

Asherman syndrome

The presence of adhesions or synechiae within the uterine cavity, usually resulting from scar formation after surgery or a D&C.

PCOS (Polycystic Ovarian Disease)

An endocrine disorder characterized by chronic anovulation, infertility, and a "string of pearls" appearance of the ovaries.

Endometrioma

Also known as a "chocolate cyst," it is a localized collection of ectopic endometrial tissue located in the adnexa, frequently appearing as a cystic mass with low-level echoes.

Cystic Teratoma

Also known as a Dermoid, it is the most common benign ovarian tumor in reproductive-age women, composed of three germ layers (ectoderm, mesoderm, endoderm).

Meigs syndrome

A clinical triad consisting of a benign ovarian tumor (usually a fibroma), ascites, and pleural effusion.

Krukenberg tumor

A metastatic ovarian tumor, usually originating from the GI tract (stomach), characterized by bilateral ovarian masses and ascites.

Ovarian Volume Formula

The calculation used to determine the volume of an ovary: $L \times W \times H \times 0.523$.

Blastocyst

A stage of the fertilized egg at day 5 where cell differentiation occurs, consisting of an outer trophoblast and an inner embryoblast.

Mean Sac Diameter (MSD)

A measurement calculated as $(length + height + width) / 3$; the gestational sac grows approximately $1mm$ per day.

Crown Rump Length (CRL)

The most reliable estimation of gestational age in the first trimester; the formula for GA is $CRL \text{(cm)} + 6.5 = GA \text{(weeks)}$.

Physiologic bowel herniation

A normal first-trimester migration of midgut bowel into the base of the umbilical cord that should be completed by $12$ weeks.

Nuchal Translucency (NT)

The fluid-filled layer between the fetus and the skin in the first trimester; a measurement $>3mm$ is considered abnormal.

Heterotopic pregnancy

The rare occurrence of a coexisting intrauterine pregnancy and an ectopic pregnancy.

Hydatidiform Mole

A type of Gestational Trophoblastic Disease resulting in a "vesicular snowstorm" or "swiss cheese" appearance of the uterus with markedly elevated hCG.

Levocardia

The normal cardiac position where the apex of the heart points to the left side of the chest.

Ductus venosus

A fetal shunt that carries oxygen-rich blood from the umbilical vein to the IVC, bypassing the liver.

Ductus arteriosus

A fetal shunt that directs blood from the main pulmonary artery (MPA) to the aorta, bypassing the lungs.

Tetralogy of Fallot

A cardiac syndrome consisting of four defects: overriding aorta, VSD, pulmonary stenosis, and right ventricular hypertrophy.

Rhabdomyoma

The most common fetal cardiac tumor, often associated with tuberous sclerosis.

Bochdalek hernia

The most common type of diaphragmatic hernia, occurring on the left side and containing the stomach, bowel, and left lobe of liver.

Aqueductal stenosis

The most common cause of fetal hydrocephalus, involving narrowing of the Aqueduct of Sylvius and dilation of the third and lateral ventricles.

Alobar holoprosencephaly

The most severe form of holoprosencephaly, characterized by a horseshoe-shaped monoventricle and fused thalami.

Dandy-Walker Malformation

A brain defect resulting in a "key-hole appearance" due to the absence of the cerebellar vermis and dilation of the fourth ventricle.

Arnold-Chiari II Malformation

A cranial deformity associated with open spina bifida, characterized by a "lemon-shaped" head and a "banana-shaped" cerebellum.

Cystic Hygroma

A pocket of lymphatic fluid under the skin, most common in the neck; it is strongly associated with Turner’s syndrome.

Thanatophoric dysplasia

The most common lethal skeletal dysplasia, characterized by a cloverleaf-shaped skull and "telephone receiver" bowed long bones.

Sirenomelia

Also known as "mermaid syndrome," it is characterized by the fusion of the lower extremities and is often associated with bilateral renal agenesis.

Gastroschisis

A right-sided abdominal wall defect where bowel herniates without a covering membrane; it is associated with highly elevated AFP.

Omphalocele

A midline abdominal wall defect where organs herniate into the base of the umbilical cord covered by a membrane; it has a strong association with chromosomal abnormalities.

Potter’s syndrome

A condition resulting from bilateral renal agenesis, characterized by no visible bladder and severe oligohydramnios.

Prune Belly Syndrome

Also known as Eagle-Barrett syndrome, it consists of a triad of absent abdominal musculature, undescended testis, and urinary tract abnormalities.

Trisomy 21 (Down's syndrome)

The most common aneuploidy, associated with an absent nasal bone, thickened nuchal fold, and duodenal atresia.

Trisomy 18 (Edwards syndrome)

A fatal trisomy associated with choroid plexus cysts, strawberry-shaped skull, micrognathia, and clenched hands.

Trisomy 13 (Patau’s syndrome)

A fatal trisomy associated with holoprosencephaly, facial abnormalities, polydactyly, and clubfeet.

Twin-to-Twin Transfusion Syndrome (TTTS)

A complication of monochorionic twins where fetal shunting occurs, resulting in a smaller donor twin with oligohydramnios and a larger recipient twin with polyhydramnios.

Twin Reversed Arterial Perfusion (TRAP)

A sequence where an acardiac parasitic twin is supported by a normal "pump" twin through vascular anastomoses.

Placenta accreta

The general term for abnormal adherence of the placenta to the myometrium, specifically when it is adhered to the wall but does not invade.

Vasa Previa

A critical condition where fetal vessels are implanted across the internal os, risking rupture during cervical dilation.

Asymmetric IUGR

A "brain-sparing" growth restriction where the head stays normal size while the body is small, often due to placental insufficiency.

ALARA

A safety principle in ultrasound standing for "As Low As Reasonably Achievable," focused on minimizing acoustic exposure.