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: Further testing will not be performed to determine the meaning of this score, as the biophysical profile score is a reliable indicator of fetal well-being. It is a combination of five parameters: fetal breathing movements, fetal movements, fetal tone, amniotic fluid volume, and fetal heart rate. Each parameter is scored as 0 (abnormal) or 2 (normal), and the total score ranges from 0 to 10.

Choice B reason: The test results are within normal limits, as a biophysical profile score of 8 or higher indicates a healthy fetus with a low risk of hypoxia or acidosis. It also suggests that the placenta is functioning adequately and the pregnancy can continue safely.

Choice C reason: An obstetric specialist will not evaluate the results of this profile and, within the next week, will inform you of your options regarding delivery, as the biophysical profile score is interpreted by the nurse or the health care provider who performed the test. It is not a diagnostic test that requires a consultation with a specialist.

Choice D reason: Immediate delivery by cesarean birth is not being considered, as the biophysical profile score of 8 does not indicate any fetal distress or complication that would warrant an urgent intervention. Cesarean birth may be indicated for other reasons, such as malpresentation, placenta previa, or failure to progress in labor.