A nurse is caring for a laboring client at 40 weeks gestation. The fetal heart rate monitor shows late decelerations with each contraction, and the baseline fetal heart rate has dropped from 140 bpm to 110 bpm over the past 30 minutes. The client is currently in the supine position. What is the nurse's priority intervention?

Late decelerations with a dropping baseline indicate fetal hypoxia due to uteroplacental insufficiency. Repositioning to left lateral is the priority to relieve aortocaval compression and improve placental perfusion. Oxygen and fluids are secondary, and cesarean is reserved if conservative measures fail.

Clinical Scenario Analysis

The fetal heart rate (FHR) monitor reveals two critical findings: late decelerations with each contraction and a declining baseline FHR from 140 bpm to 110 bpm over 30 minutes. Late decelerations are a hallmark of uteroplacental insufficiency (UPI), where the fetus experiences transient hypoxemia during uterine contractions because placental perfusion is compromised . The gradual drop in baseline FHR suggests the fetus is depleting its glycogen reserves and transitioning from a compensatory sympathetic response to a decompensatory state, risking metabolic acidosis . This pattern is a classic, non-reassuring fetal heart rate status (NRFHRS), which is strongly associated with fetal hypoxia and adverse perinatal outcomes .

Prioritizing Nursing Interventions

The nurse must apply the least invasive, most rapidly effective intervention first to correct the underlying physiological insult. The client is currently in the supine position. In this position, the gravid uterus compresses the maternal aorta and inferior vena cava, a condition known as supine hypotensive syndrome or aortocaval compression. This mechanical compression directly reduces maternal cardiac output and placental blood flow, which is the most immediate and reversible cause of the observed UPI and late decelerations .

Therefore, the priority intervention is to alleviate this compression. Repositioning the client to the left lateral position displaces the uterus off the great vessels, immediately improving maternal venous return, cardiac output, and uteroplacental perfusion. This simple action often resolves the late decelerations and allows the fetal heart rate to recover without further intervention.

The other options are important but are secondary or tertiary interventions to be performed if repositioning fails to resolve the pattern:
- Administering oxygen (Option 1) increases the oxygen gradient for diffusion but will be ineffective if placental blood flow is mechanically obstructed.
- Increasing intravenous fluids (Option 2) can expand maternal circulating volume and support cardiac output, but it does not directly remove the mechanical obstruction caused by the supine position.
- Preparing for immediate cesarean delivery (Option 3) is the definitive treatment for persistent NRFHRS indicating fetal intolerance to labor, but it is not the first-line action before attempting intrauterine resuscitation measures .