Diagnosis of Pregnancy and Dating

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?

A 28-year-old woman presents with amenorrhea of 6 weeks. Urine beta-hCG is positive. She has no risk factors for ectopic pregnancy. What is the investigation of choice to confirm intrauterine pregnancy and establish accurate dating?