Final answer:
Monitoring fetal heart rate is the crucial nursing intervention during the first stage of labor. This stage involves the cervix thinning and dilation, with oxytocin driving the contractions and progesterone decreases, aiding cervix dilation.
Step-by-step explanation:
The crucial nursing intervention when caring for a pregnant patient in the first stage of labor is c) Monitoring fetal heart rate. The first stage of labor involves the thinning and dilation of the cervix, which is necessary for the baby and placenta to be expelled during birth. This stage does not require the administration of pain medication as a primary intervention, and pushing efforts are not encouraged until the second stage of labor when the baby is being expelled from the uterus. Initiating breastfeeding is also not applicable in the first stage of labor.
It is also important to understand the role hormones play during labor. The hormone oxytocin is primarily responsible for the contractions during labor, while a decrease in progesterone towards the end of pregnancy helps to bring on labor by decreasing the inhibition of uterine contractility, as this allows for the cervix to dilate appropriately.