Clinical Obstetrics and Gynecology Syllabus

After 20 weeks, how does symphysis-fundal height (in cm) relate to gestational age?

The fundal height in centimeters approximately equals the gestational age in weeks ($\pm 2$ cm), e.g., about 30 cm at 30 weeks.

What does the first-trimester combined screening test measure to assess aneuploidy risk?

Nuchal translucency on ultrasound plus maternal serum beta-hCG and PAPP-A (pregnancy-associated plasma protein A), done at 11–14 weeks.

What four analytes are measured in the second-trimester "quad screen"?

Alpha-fetoprotein (AFP), beta-hCG, unconjugated estriol, and inhibin A.

How does non-invasive prenatal testing (NIPT) work, and what is it used to detect?

NIPT analyzes cell-free fetal DNA in maternal blood (from about 10 weeks) to screen for common aneuploidies such as trisomy 21, 18, and 13, and fetal sex/Rh status. It is a screening, not diagnostic, test.

Compare chorionic villus sampling (CVS) and amniocentesis in timing and sampled tissue.

CVS samples placental (chorionic villus) tissue at 10–13 weeks; amniocentesis samples amniotic fluid at 15–20 weeks. Both are diagnostic for chromosomal/genetic conditions and carry a small miscarriage risk.

How is gestational diabetes screened for, and what test confirms it?

Screening at 24–28 weeks with a 50 g 1-hour glucose challenge test; if abnormal, confirm with a 3-hour 100 g oral glucose tolerance test (OGTT). Some use a one-step 75 g 2-hour OGTT.

How much folic acid is recommended before and in early pregnancy, and why?

$400\text{–}800\ \mu g$ daily (up to 4 mg for high-risk women), started ideally at least 1 month before conception, to reduce the risk of fetal neural tube defects.

What is the recommended total weight gain during pregnancy for a woman with a normal pre-pregnancy BMI?

About 11.5–16 kg (25–35 lb) for a normal BMI ($18.5 \leq \text{BMI} < 25$). Recommendations are higher for underweight and lower for overweight/obese women.

Name three foods or substances pregnant women are advised to avoid, and the main reason for each.

High-mercury fish (neurotoxicity), unpasteurized dairy/deli meats (listeriosis risk), raw/undercooked meat and eggs (toxoplasmosis, salmonella), and alcohol (fetal alcohol spectrum disorders).

What are the three stages of labor?

First stage: onset of regular contractions to full cervical dilation (10 cm). Second stage: full dilation to delivery of the baby. Third stage: delivery of the baby to delivery of the placenta.

How are the latent and active phases of the first stage of labor distinguished?

The latent phase is slow cervical dilation from 0 to about 6 cm with irregular contractions; the active phase is more rapid dilation from about 6 cm to 10 cm with strong regular contractions.

List the cardinal movements of labor in order.

Engagement, descent, flexion, internal rotation, extension, external rotation (restitution), and expulsion.

What defines the third stage of labor as prolonged, and what are three signs of placental separation?

Prolonged if the placenta is undelivered after 30 minutes. Signs of separation: a gush of blood, lengthening of the umbilical cord, and rising/globular firm uterus.

Define preterm labor and post-term pregnancy by gestational age.

Preterm labor: regular contractions with cervical change before 37 weeks. Post-term (postdates) pregnancy: gestation continuing beyond 42 weeks.

What is shoulder dystocia, and name one common maneuver used to relieve it.

Shoulder dystocia is impaction of the fetal anterior shoulder behind the maternal pubic symphysis after delivery of the head. The McRoberts maneuver (hyperflexion of maternal hips) with suprapubic pressure is first-line.

Distinguish primary and secondary arrest/failure to progress in labor.

Primary dysfunctional labor is inadequate progress from early active labor; secondary arrest is cessation of previously normal progress. Causes fall into the "3 Ps": Power (contractions), Passenger (fetal size/position), and Passage (pelvis).

What is umbilical cord prolapse, and why is it an obstetric emergency?

It is descent of the umbilical cord below or alongside the presenting part after membrane rupture. It is an emergency because cord compression cuts off fetal blood flow, requiring immediate delivery (usually cesarean).

Differentiate a first-degree from a fourth-degree perineal laceration.

First-degree: involves only vaginal mucosa/perineal skin. Fourth-degree: extends through the perineal muscles, anal sphincter complex, and the rectal (anal) mucosa.

What is the difference between an elective and an emergency cesarean section?

An elective (planned) cesarean is scheduled before labor for a known indication (e.g., placenta previa, breech). An emergency cesarean is performed urgently for maternal or fetal compromise during labor (e.g., fetal distress, cord prolapse).

When are forceps or vacuum-assisted (operative vaginal) deliveries indicated?

In the second stage when the head is engaged and cervix fully dilated, for prolonged second stage, maternal exhaustion, fetal distress, or the need to avoid maternal pushing (e.g., cardiac disease).

What are the classic criteria for a normal spontaneous vaginal delivery ("normal labor")?

Spontaneous onset at term (37–42 weeks), single fetus in vertex (cephalic) presentation, delivery within a reasonable time frame without instruments, and no complications for mother or baby.

What are lochia, and describe the normal color progression postpartum.

Lochia is the postpartum vaginal discharge of blood, tissue, and mucus. It progresses from lochia rubra (red, days 1–3) to lochia serosa (pinkish-brown, days 4–10) to lochia alba (yellow-white, up to ~6 weeks).

Define primary postpartum hemorrhage and give its most common cause.

Primary PPH is blood loss $\geq 500$ mL after vaginal delivery ($\geq 1000$ mL after cesarean) within 24 hours of birth. The most common cause is uterine atony.

What is the significance of uterine involution and fundal position in the immediate postpartum period?

Involution is the uterus returning toward its pre-pregnancy size. The fundus is at about the umbilicus after delivery and descends roughly 1 cm (one fingerbreadth) per day, becoming non-palpable abdominally by about 2 weeks.

Which hormones drive milk production and milk ejection (let-down), and what stimulates each?

Prolactin drives milk synthesis (production); oxytocin drives the let-down (milk ejection) reflex. Both are stimulated by infant suckling; oxytocin is also released by the sight/sound of the baby.

What is colostrum, and why is it important for the newborn?

Colostrum is the thick yellowish first milk produced in the first few days postpartum. It is rich in protein and immunoglobulins (especially secretory IgA), providing passive immunity and acting as a natural laxative to pass meconium.

How does "baby blues" differ from postpartum depression in timing and severity?

Baby blues are mild, transient mood swings/tearfulness affecting up to ~80% of mothers, peaking around days 3–5 and resolving within 2 weeks. Postpartum depression is a more severe, persistent depression lasting >2 weeks, typically within the first year, that impairs function and needs treatment.

What screening tool is commonly used for postpartum depression, and what is a key red-flag symptom requiring urgent care?

The Edinburgh Postnatal Depression Scale (EPDS). Thoughts of self-harm or harming the baby (or symptoms of postpartum psychosis) are red flags requiring urgent evaluation.

Define amenorrhea and distinguish primary from secondary amenorrhea.

Amenorrhea is the absence of menstruation. Primary: no menarche by age 15 (with normal secondary sexual characteristics) or by 13 without them. Secondary: cessation of previously present menses for $\geq 3$ months (or 3 cycles).

Differentiate menorrhagia, metrorrhagia, and dysmenorrhea.

Menorrhagia: heavy or prolonged menstrual bleeding at regular intervals. Metrorrhagia: irregular bleeding between periods. Dysmenorrhea: painful menstruation (cramping).

What is the classic clinical triad/features and typical cause of pelvic inflammatory disease (PID)?

PID is an ascending infection of the upper genital tract, usually from Chlamydia trachomatis or Neisseria gonorrhoeae. Features include lower abdominal/pelvic pain, cervical motion tenderness, adnexal/uterine tenderness, fever, and abnormal discharge; a serious complication is Fitz-Hugh–Curtis syndrome (perihepatitis).

What is endometriosis, and what are its three classic symptoms?

Endometriosis is the presence of endometrial-like tissue outside the uterine cavity. The classic triad is dysmenorrhea, dyspareunia (painful intercourse), and infertility; cyclical pain and chronic pelvic pain are hallmark features.

Compare a functional (follicular) ovarian cyst with a corpus luteum cyst.

A follicular cyst forms when an ovarian follicle fails to rupture and continues growing; it is usually asymptomatic and resolves spontaneously. A corpus luteum cyst forms when the corpus luteum fails to regress and fills with fluid/blood; it can cause pain and occasionally rupture or hemorrhage.