Antenatal Visits and Investigations

A 28-year-old primigravida at 16 weeks of gestation attends her first antenatal visit. She is asymptomatic with a normal obstetric examination. Her booking blood tests show: Hb 11.2 g/dL, blood group O positive, negative infectious serology (HIV, HBsAg, VDRL, rubella IgM). She has no significant past medical history. What is the most appropriate next investigation at this visit?

A 28-year-old primigravida at 32 weeks of gestation is screened for anemia. Her hemoglobin is 9.5 g/dL. Which laboratory finding best distinguishes iron deficiency anemia from anemia of chronic disease in pregnancy?

A 32-year-old multigravida at 20 weeks of gestation presents for her routine antenatal visit. She reports no complaints. Obstetric examination is unremarkable. Her first-trimester combined screening (NT + biochemistry) showed a low risk for chromosomal abnormalities (risk 1 in 2500). She has no significant past medical history and is not diabetic. What is the most appropriate next investigation at this visit?

During routine antenatal care at 16 weeks of gestation, a 32-year-old woman undergoes the triple screen (maternal serum screening). Which is the most common chromosomal abnormality detected by this test in the Indian population?

At which antenatal visit is the routine oral glucose tolerance test (OGTT) or random blood glucose screening recommended in India?