The maternity nurse understands that vascular volume increases 40% to 45% during pregnancy to:

Choice A reason: Amniocentesis for fetal lung maturity is not an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a procedure that involves inserting a needle into the amniotic sac to obtain a sample of amniotic fluid, which can be used to assess the fetal lung development. It is usually done in late pregnancy or preterm labor, not in the second trimester.

Choice B reason: Contraction stress test (CST) is not an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a test that involves stimulating uterine contractions, either by nipple stimulation or oxytocin infusion, to evaluate the fetal heart rate response. It is used to assess fetal well-being and placental function, not to diagnose the cause of bleeding.

Choice C reason: Internal fetal monitoring is not an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a method of measuring the fetal heart rate and uterine contractions using electrodes or catheters that are inserted through the cervix and attached to the fetal scalp or the amniotic sac. It is usually done during labor, not in the second trimester.

Choice D reason: Ultrasound for placental location is an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a test that uses sound waves to create an image of the uterus, the placenta, and the fetus. It can help to determine the position and attachment of the placenta, which can be the cause of bleeding if it is low-lying or covering the cervix (placenta previa).

Choice E reason: None of the above is not a correct answer. There is one expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding, which is ultrasound for placental location.

Choice A reason: This is not the correct answer, as the pregnant woman does not use glucose at a more rapid rate than the nonpregnant woman. In fact, the pregnant woman has lower fasting glucose levels and higher postprandial glucose levels than the nonpregnant woman. This is because the pregnant woman adapts to the increased fetal demand for glucose by increasing her insulin secretion and decreasing her hepatic glucose production.

Choice B reason: This is the correct answer, as placental hormones are antagonistic to insulin, thus resulting in insulin resistance. Insulin resistance is a condition where the cells do not respond well to insulin and require more insulin to maintain normal glucose levels. Placental hormones, such as human placental lactogen, progesterone, and cortisol, increase the insulin resistance of the maternal tissues, especially in the second and third trimesters of pregnancy. This is to ensure that the fetus has enough glucose supply, as the placenta is not insulin resistant and can transport glucose to the fetus².

Choice C reason: This is not the correct answer, as pancreatic function in the islets of Langerhans is not affected by pregnancy. The islets of Langerhans are clusters of cells in the pancreas that produce hormones, such as insulin and glucagon, that regulate glucose metabolism. Pregnancy does not impair the function of the islets of Langerhans, but rather stimulates them to increase their size and number. This is to compensate for the increased insulin resistance and glucose demand of the pregnancy.

Choice D reason: This is not the correct answer, as the pregnant woman does not increase her dietary intake significantly. The pregnant woman needs to consume adequate calories and nutrients to support the fetal growth and development, but not excessively. The recommended weight gain during pregnancy depends on the pre-pregnancy BMI of the woman, but generally ranges from 11 to 16 kg. The recommended calorie intake during pregnancy is about 300 kcal more than the pre-pregnancy intake, which is equivalent to one extra snack per day.