NSG 3323 Lecture Notes - Lecture 19: Gestational Age, Human Chorionic Gonadotropin, Femur
Document Summary
Diagnostic procedure = accuracy dependent on person performing exam. Transducer = uses high frequency sound waves that bounce off the fetus to produce an image called a sonogram. Transvaginal transducer = primarily used in 1st trimester and does not require a full bladder. Transabdominal transducer = moved across the abdomen and may require a full bladder. Crown rump measurement = most accurate 6-10 weeks. Greater than 12 weeks - biparietal diameter (bpd) and femur length (fl) Monitor fetal growth through a series of us measurements. Identi cation of gross fetal anomalies during fetal anatomy surgery > 20 weeks. Assessment of fetal well being in the first trimester: Quantitative serum beta hcg testing = very accurate marker of presence of pregnancy and placental health. Should double every 2 days for the rst 10 days of pregnancy peaking at 60-90 days. Progesterone level = secreted by the corpus lute until approximately 8 weeks than manufactured by the placenta.
