The nurse is calculating the estimated date of confinement (EDC) using Nagele's rule for a client whose last menstrual period started on February 13th. Which date is most accurate?

Choice A reason: Biophysical profile is a test that assesses the fetal well-being by measuring five parameters: fetal breathing movements, fetal movements, fetal tone, amniotic fluid volume, and fetal heart rate. It does not predict chromosomal abnormalities in the fetus.

Choice B reason: Lecithin/sphingomyelin [L/S] ratio is a test that measures the amount of two phospholipids in the amniotic fluid. It is used to evaluate the fetal lung maturity and the risk of respiratory distress syndrome. It does not predict chromosomal abnormalities in the fetus.

Choice C reason: Type and crossmatch of maternal and fetal serum is a test that determines the blood type and Rh factor of the mother and the fetus. It is used to identify the risk of hemolytic disease of the newborn due to Rh incompatibility. It does not predict chromosomal abnormalities in the fetus.

Choice D reason: Multiple-marker screening is a test that measures the levels of four substances in the maternal serum: alpha-fetoprotein, human chorionic gonadotropin, unconjugated estriol, and inhibin A. It is used to estimate the risk of Down syndrome, trisomy 18, and neural tube defects in the fetus.

Choice A reason: This is not a good intervention, as it may worsen the symptoms of faintness, dizziness, and agitation. Standing up can cause a sudden drop in blood pressure (orthostatic hypotension), which can reduce the blood flow to the brain and the fetus. This can cause lightheadedness, blurred vision, and loss of consciousness in the woman, as well as fetal distress or hypoxia.

Choice B reason: This is not a good intervention, as it may also worsen the symptoms of faintness, dizziness, and agitation. Lying supine can cause compression of the inferior vena cava (a large vein that returns blood to the heart) by the gravid uterus, which can reduce the cardiac output (the amount of blood pumped by the heart) and the blood pressure. This can cause nausea, sweating, and visual disturbances in the woman, as well as fetal distress or hypoxia.

Choice C reason: This is not a good intervention, as it may not improve the symptoms of faintness, dizziness, and agitation. Sitting down and holding the arm in a dependent position can lower the blood pressure in the arm, but not in the rest of the body. This can cause inaccurate readings of the blood pressure and delay the detection of hypotension or hypertension. This can also cause discomfort and pain in the arm due to impaired circulation.

Choice D reason: This is the best intervention, as it can relieve the symptoms of faintness, dizziness, and agitation by improving the blood flow to the brain and the fetus. Turning to the left side can reduce the pressure of the uterus on the inferior vena cava and increase the cardiac output and the blood pressure. This can also optimize the placental perfusion (the blood flow to the placenta) and the fetal oxygenation.