Diagnosis of Pregnancy and Dating

A 32-year-old primigravida at 14 weeks gestation by menstrual history presents for dating ultrasound. Transvaginal ultrasound shows a crown-rump length of 68 mm. Which is the most appropriate next investigation to refine dating accuracy if there is a discrepancy between LMP and ultrasound measurement?

A 28-year-old woman attends the antenatal clinic at 12 weeks gestation. She has regular 28-day cycles and reports her last menstrual period (LMP) as 12 weeks ago. Transvaginal ultrasound shows a crown-rump length (CRL) of 58 mm. Which feature best distinguishes dating by LMP from dating by first-trimester ultrasound in this scenario?

A 32-year-old woman from Mumbai attends the antenatal clinic at 12 weeks of gestation (by LMP). On transvaginal ultrasound, the crown-rump length (CRL) measures 52 mm. The nuchal translucency (NT) is 1.8 mm. Fetal cardiac rate is 155 bpm. Based on the CRL measurement, what is the revised gestational age, and what is the margin of error for dating at this stage?

A 28-year-old married woman from Delhi presents to the antenatal clinic with amenorrhea for 6 weeks. She reports breast tenderness and mild nausea in the mornings. On examination, her uterus is palpable just above the symphysis pubis and is soft with a bluish tinge to the cervix. A urine pregnancy test (hCG) is positive. Transvaginal ultrasound shows a gestational sac of 8 mm diameter in the uterine cavity with no yolk sac visible. What is the most accurate assessment of gestational age based on the gestational sac diameter?

A 32-year-old woman with a positive urine pregnancy test at home attends the antenatal clinic. She is uncertain about her last menstrual period (LMP). Transvaginal ultrasound shows a gestational sac of 8 mm with no yolk sac. What is the drug of choice for medical management if she opts for termination of pregnancy at this stage?