A nurse is preparing to measure an infant’s vital signs.

Which of the following sites should the nurse use to assess the heart rate?

Choice A rationale
Uterine atony refers to a soft and weak uterus after childbirth. It happens when your uterine muscles don’t contract enough to clamp the placental blood vessels shut after childbirth. This can lead to life-threatening blood loss after delivery. One of the causes of uterine atony is urinary retention. When the bladder is full, it can displace the uterus, preventing it from contracting properly. This can lead to uterine atony and postpartum hemorrhage. Therefore, urinary retention can cause uterine atony and lateral displacement of the fundus.
Choice B rationale
Poor involution of the uterus is a condition where the uterus does not return to its normal size after childbirth. While poor involution can lead to prolonged bleeding, it does not directly cause uterine atony. Uterine atony is specifically a lack of muscle contraction, while poor involution is a failure of the uterus to reduce in size.
Choice C rationale
While infection can lead to many complications during the postpartum period, it is not a direct cause of uterine atony. Infections can cause endometritis, which is inflammation of the uterine lining, but this does not prevent the uterus from contracting.
Choice D rationale
Hemorrhage, or heavy bleeding, is a result of uterine atony, not a cause. When the uterus does not contract properly after childbirth, it can lead to excessive bleeding, or hemorrhage.

Choice A rationale
While reduced fetal oxygen supply can occur with hypertonic contractions and inadequate uterine relaxation, it’s not the primary adverse effect. The main concern is the impact on the progress of labor.
Choice B rationale
This is the correct answer. Inadequate uterine relaxation between hypertonic contractions can delay cervical dilation, slowing the progress of labor.
Choice C rationale
Prolonged labor is not typically associated with hypertonic contractions and inadequate uterine relaxation. In fact, these conditions can lead to a more rapid labor.
Choice D rationale
Increased maternal stress can occur with any labor complication, but it’s not the primary adverse effect of hypertonic contractions and inadequate uterine relaxation.