Health Promotion and Maintenance
55. A client with preterm contractions at 34 weeks' gestation is dilated to 3 cm. A physician orders an amniocentesis for fetal lung maturity. Which laboratory test will provide the most information to a nurse about fetal lung maturity?
. Human chorionic gonadotropin (HCG).
. Phosphatidylglycerol (PG).
. α-Fetoprotein (AFP).
. Partial thromboplastin time (PTT).
Test-Taking Tip
The key to this question is choosing the proper laboratory test. Eliminate the alternative that is obviously not specific to pregnancy.
Content Area: Maternity, Intrapartum; Integrated Process: Nursing Process, Assessment; Cognitive Level: Comprehension; Client Need/Subneed: Physiological Integrity/Reduction of Risk Potential/Laboratory Values
Health Promotion and Maintenance
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Answer 1 is incorrect because human chorionic gonadotropin (HCG) is a hormone produced by the developing placenta that prevents the corpus luteum from deteriorating and secretes estrogen and progesterone, which maintains the pregnancy for the first 20 weeks of gestation. It is found in maternal blood and urine. Answer 2 is correct because phosphatidylglycerol (PG) is a major phospholipid of surfactant. The presence of PG in amniotic fluid indicates fetal lung maturity. Answer 3 is incorrect because α-fetoprotein (AFP) is a plasma protein that is produced by the fetus. Abnormally high or low levels can indicate fetal anomalies. AFP levels are drawn from maternal blood. Answer 4 is incorrect because partial thromboplastin time (PTT) levels are drawn to determine if anticoagulant drugs are at a therapeutic level in women with thromboembolic disease.