Antenatal care for NEET PG: six pictures from the booking visit to the growth scan

Answer: D. Venous return and cardiac output fall

Venous return and cardiac output fall. Vessel 2 is the inferior vena cava, the thin-walled vein to the right of the spine, so it flattens under the uterus when she lies flat. Less blood returns to the heart, so stroke volume and cardiac output fall. Most women compensate through paravertebral veins and a rise in tone; a few cannot. Left lateral tilt rolls the uterus off the cava and reverses the fall within minutes.

Why the closest rival loses: arterial inflow to the legs (C) is not the problem: vessel 1, the aorta, keeps its lumen because of its thick wall. A vagal bradycardia (A) is not the cause: the collapse is mechanical and recovers with tilt. The claim that placental perfusion is unaffected (B) is wrong: it falls too, so the fetal heart rate can drop. The same effect is why chest compressions in late pregnancy are given with the uterus displaced to the left.

Recallab question 55971 · Obstetrics › Physiological Changes of Pregnancy · reference: DC Dutta's Textbook of Obstetrics

Answer: C. Drawing 1

Drawing 1. The lower strap goes under the bump and across the front of the bony pelvis, and the diagonal strap passes between the breasts and down the side of the abdomen. The bony pelvis can take a restraint load; the pregnant uterus cannot. A strap lying across the fundus presses the uterus against the spine on deceleration, and because the placenta does not stretch with the uterine wall, it shears away: abruption, the commonest cause of fetal death in a survivable crash.

Why the closest rival loses: drawing 2 (D) has its lower strap directly over the uterus, which delivers the crash load to the placental bed. Drawing 3 (A) has the diagonal strap tucked under the arm, which lets the upper body jack-knife over the lap strap. Drawing 4 (B), with no belt, is worse than any belt: being thrown forward is more dangerous than the strap. Under the bump, between the breasts.

Recallab question 58372 · Obstetrics › Antenatal Care · reference: DC Dutta's Textbook of Obstetrics

Answer: B. Device 1

Device 1, a handheld Doppler. It turns the frequency shift from moving fetal blood into sound and detects the heart through the abdominal wall from about 10 to 12 weeks. At 14 weeks the heart sounds themselves are far too faint to hear directly. Transvaginal ultrasound shows the cardiac activity from about 6 weeks.

Why the closest rival loses: device 2 (D) is the Pinard stethoscope, which carries the heart sounds themselves and hears them only from about 20 weeks. Device 3 (A), an ordinary stethoscope, is even less suited, since direct listening works only later. Device 4 (C) is a cardiotocograph, which records the heart rate over time in late pregnancy and labour. Scan at 6, Doppler at 12, Pinard at 20.

Recallab question 58072 · Obstetrics › Diagnosis Of Pregnancy · reference: DC Dutta's Textbook of Obstetrics

Answer: D. Ultrasound scan

An ultrasound scan. After 24 weeks the height in centimetres should lie within about two to three of the gestation in weeks. Here the tape reads 34 cm at 28 weeks, six centimetres too large, and the dates are secure because an early scan fixed them. So something beyond a single normal fetus fills the uterus: twins, excess fluid, a large baby or a fibroid. One scan tells these apart, so it comes first.

Why the closest rival loses: repeating the measurement in four weeks (C) only delays finding the cause when the reading is well outside the accepted range. Reassurance (B) is wrong because the tape detects a uterus that is too large as well as too small. A glucose tolerance test (A) is considered once the scan shows which cause is present. Centimetres equal weeks, give or take three.

Recallab question 55773 · Obstetrics › Antenatal Care · reference: DC Dutta's Textbook of Obstetrics

Answer: A. Woman C

Woman C. Her chart records ten movements comfortably for eleven days and then falls short three days running. A fall from her own baseline matters more than any absolute number. A definite reduction is assessed the same day, with a history, a heart rate tracing and a scan for growth and liquor, because reduced movement precedes some stillbirths and is never left to the next clinic.

Why the closest rival loses: woman B (C) is slow, about eight hours to reach ten, but unchanged on every day, so it is her normal pattern. Woman A (B) reaches ten in about two hours every day. Woman D (D) shows ordinary day-to-day variation within a few hours and reaches ten every day. Her own pattern is the reference, and the visit is today.

Recallab question 58475 · Obstetrics › Antenatal assessment of Fetus · reference: DC Dutta's Textbook of Obstetrics

Answer: D. Section A

Section A. The abdominal circumference is traced on the transverse section showing the stomach bubble and the short umbilical segment of the left portal vein within the liver, with the kidneys out of view. Those two landmarks fix the plane. A falsely large circumference conceals the growth restriction the scan was done to find.

Why the closest rival loses: section D (C) shows the same landmarks but its outline is an ellipse with three ribs on one side: an oblique cut, which inflates the measurement. Section B (A) is below the plane, because both kidneys are showing. Section C (B) is above it: the four-chambered heart marks the thorax. Stomach and vein in; kidneys and heart out; round, not oval.

Recallab question 57469 · Obstetrics › Antenatal assessment of Fetus · reference: DC Dutta's Textbook of Obstetrics