A nurse is assisting in the care of a client who is in active labour. The nurse notes variable decelerations of the FHR. The nurse should identify which of the following is a cause of variable decelerations.

Choice D rationale:

The correct answer is Choice D. The biophysical profile is a prenatal test used to assess fetal well-being in the third trimester of pregnancy. It is not used to determine the estimated date of birth (Choice A), as that is typically calculated based on the first day of the last menstrual period and confirmed or adjusted by early ultrasounds.

The test also does not require the client to be NPO (nothing by mouth) for 8 hours prior to the test (Choice B). This restriction is commonly associated with certain medical procedures, but it is not applicable to the biophysical profile.

Furthermore, there is no need to initiate an IV (intravenous line) before the biophysical profile (Choice C). The test is non-invasive and involves the use of ultrasound and fetal heart rate monitoring. The biophysical profile assesses several fetal parameters, such as fetal movement, fetal tone, fetal breathing movements, amniotic fluid volume, and the fetal heart rate. These parameters help evaluate the well-being and health of the baby. The test is often recommended in cases of high-risk pregnancies, decreased fetal movement, or other conditions that may warrant closer monitoring of the baby's condition. By knowing that the biophysical profile predicts fetal well-being in the third trimester, the nurse can provide accurate information to the client, reassuring them about the health of their baby and explaining the importance of the test in ensuring a safe delivery and healthy outcome.

Choice A rationale:
0.25 mL - The nurse should not administer 0.25 mL because the available concentration of vitamin K injection is 1 mg/0.5 mL. To achieve the prescribed dose of 1 mg, administering only 0.25 mL would be insufficient.
Choice B rationale:
0.5 mL - This is the correct choice. The nurse should administer 0.5 mL of the vitamin K injection to deliver 1 mg of vitamin K, as the concentration of the injection is 1 mg/0.5 mL. By giving the full 0.5 mL, the newborn will receive the appropriate 1 mg dose.
Choice C rationale:
0.75 mL - Administering 0.75 mL would be excessive for the prescribed 1 mg dose of vitamin K. It is unnecessary to give a higher volume than required, as it could lead to potential adverse effects or wastage.
Choice D rationale:
1 mL - Similarly, administering the entire 1 mL of the vitamin K injection would result in doubling the prescribed dose, leading to potential overdose and adverse reactions. The nurse should avoid administering more than the necessary 0.5 mL.