Second Stage: Late Decelerations on the CTG
A 29-year-old primigravida at 40 weeks and 3 days is in the second stage of labor, fully dilated, pushing with contractions every 3 minutes lasting 60 seconds. She has an epidural in situ and has been pushing for 75 minutes. The fetal heart rate baseline is 145/min with moderate variability. Over the last 15 minutes, three decelerations have appeared: each begins after the peak of the contraction, reaches a nadir of about 100/min, and recovers slowly about 40 seconds after the contraction ends. The last three contractions have shown progressively less descent of the presenting part. Maternal BP is 108/66 mmHg, pulse 92/min, temperature 37.2 C. She is becoming exhausted and asks for 'something to help'.
1. Interpret the CTG findings and explain what they indicate about fetal status and the likely cause in this specific labor.
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Interpretation: The decelerations are late decelerations. The defining features are that they begin after the peak of the contraction and recover after the contraction has ended, and they are repetitive. The baseline (145/min) and moderate variability are reassuring background features, but repetitive late decelerations are classified as an abnormal (pathological) trace, because they signal uteroplacental insufficiency - the fetus is not getting adequate oxygen across the placenta during contractions.
Why this labor fits that picture:
- Second stage with 75 minutes of pushing means prolonged maternal expulsive effort, which reduces placental perfusion between contractions and increases maternal oxygen demand.
- The lack of progressive descent over the last three contractions suggests the fetus is not tolerating or not achieving descent, which can compound the problem (head compression, cord position, or cephalopelvic disproportion).
- Epidural analgesia can contribute to maternal hypotension and reduced uterine perfusion, though her BP here is acceptable.
Key distinction the examiner is testing: Variable decelerations (cord compression) are abrupt and often unrelated to contraction timing; early decelerations mirror the contraction and are benign. Late decelerations are the ones that demand immediate action because they reflect a fetus that is being progressively deprived of oxygen.
2. List your immediate intrauterine resuscitation measures in priority order and state what you would communicate to the obstetric team and why.
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Immediate intrauterine resuscitation, in order:
- Stop pushing / change position. Ask her to stop active pushing and turn her onto her left side (or knee-chest if the decelerations persist). This relieves aortocaval compression and improves placental blood flow.
- Maternal oxygen. Administer oxygen by mask as per unit protocol to increase maternal oxygen delivery.
- IV fluid bolus. Give a crystalloid bolus as ordered to support maternal circulating volume and placental perfusion.
- Assess for cord prolapse or other acute cause if the pattern worsens or becomes abrupt, and check whether the presenting part has descended.
- Continuous CTG monitoring and document each deceleration, its timing, and the maternal position at the time.
Communication to the obstetric team: I would call the obstetrician and midwife immediately, reporting: 'Repetitive late decelerations for 15 minutes, baseline 145 with moderate variability, nadir around 100, no progressive descent over the last three contractions, second stage at 75 minutes.' I would state clearly that I have stopped pushing, repositioned, and started oxygen and fluids, and ask for a review and a decision about delivery.
Why this matters: Repetitive late decelerations in second stage are an indication for expedited delivery if they do not resolve with resuscitation. The nurse's job is to buy time with resuscitation while escalating, not to wait and see.
3. The obstetrician decides to proceed to an instrumental delivery. Outline the nursing preparation and the specific risks you would monitor for in the immediate postpartum period.
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Preparation:
- Confirm consent and explain the procedure to the woman in plain language; she is exhausted, so keep it brief and check understanding.
- Ensure the delivery room is set up for instrumental delivery with resuscitation equipment for the newborn, and that the neonatal team is present.
- Confirm IV access is patent, and ensure oxytocin is available for active management of the third stage.
- Position her appropriately, empty the bladder if needed, and continue fetal monitoring until delivery.
Immediate postpartum risks to monitor:
- Postpartum hemorrhage. Instrumental delivery, prolonged second stage, and possible perineal trauma all increase risk. Monitor uterine tone, lochia, pulse, and BP frequently, and have oxytocin running as ordered.
- Perineal or vaginal trauma. Inspect the perineum and report excessive bleeding or hematoma; instrumental delivery raises the risk of third- and fourth-degree tears.
- Retained placenta or uterine atony, which would present as a boggy uterus and heavy bleeding.
- Newborn condition. The neonate may need assessment for birth trauma (cephalohematoma, facial nerve injury) and for the effects of the preceding hypoxia; document Apgar scores and observe closely.
- Maternal exhaustion and pain, which affect her ability to care for the baby and to mobilize safely.
Reasoning principle: The decision to deliver instrumentally resolves the fetal concern but introduces a new set of maternal risks. The nurse's monitoring plan should anticipate the complications that the intervention itself creates.