Tips for Managing Variable Decelerations : Focus not only on intensity and duration, but on how factors affect baseline in second stage of labor.


LAS VEGAS — When assessing variable decelerations in the second stage of labor, measure their depth and duration but also determine how those decelerations are affecting the baseline variability and baseline rate, Suzanne McMurtry Baird, a registered nurse clinician, advised at a conference on fetal monitoring sponsored by Symposia Medicus.

“How well is this baby tolerating those persistent variable decelerations?” asked Ms. Baird, a staff nurse in the labor and delivery unit at Vanderbilt University Medical Center, Nashville, Tenn. “Over a prolonged period of time, fetal oxygen reserves will decrease and variability will progressively decrease. Baseline rate will progressively rise if hypoxia begins. Make sure you are documenting and assessing for this and anticipating that this is a possibility. It will prolong the second stage of labor.”

Variable decelerations occur when the fetal heart rate decrease is greater than or equal to 15 beats per minute and last for longer than or equal to 15 seconds but less than 2 minutes from onset to return to baseline.

Common causes of variable decelerations include vagal reflex triggered by head compression during pushing and cord compression such as that caused by short cord, nuchal cord, body entanglement, prolapsed cord, decreased amniotic fluid, and fetal descent.

Perform a cervical exam to rule out prolapsed cord and funic presentation and check for imminent delivery.

Depending on the position of the cord, amnioinfusion could be a good option. “Some health care providers like this option and use it,” Ms. Baird said. However, she noted that the consistent efficacy of this measure is “very up in the air.”

Nevertheless, communication with the patient is key during variable decelerations. “Notify this patient and let the family know,” said Ms. Baird, who also teaches at the Vanderbilt University School of Nursing. “They may get real excited and see a [fetal] heart rate of 60 [bpm]. Have you had the heart rate disappear during that time because you're [doing] an ultrasound? I've heard patients say that the baby's heart rate stopped with every contraction. It wasn't stopping. We just failed to tell them that we weren't tracing that heart rate at the end of a deceleration.”

Ms. Baird emphasized that “there is no place” for uterine hyperstimulation when a woman is experiencing persistent variable decelerations or persistent late decelerations.

“Oftentimes, I see nurses turning the Pitocin up, even in the presence of all of these patterns and we're at 1–2 minute uterine contractions,” Ms. Baird said at the conference.

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