A 26 years old female at 39 weeks gestation presents with gush of fluid and regular contractions. On examination, she is grossly ruptured, contraction every two minutes and a cervical dilatation of 4 cms. The fetal heart rate is 140/min and reactive. She was admitted for labor and delivery. Over the next four hours, the cervical dilatation progressed to 9 cms. In the past hour, the fetal heart rate increased from the baseline of 140/min to 160/min. There is moderate to severe variable decelerations are seen with each contraction. The fetal heart rate does not responds to scalp stimulation. It was decided to proceed for caesarean section. The most important reason for the decision is
Answer: d) Non reassuring fetal heart rate tracingCardio toco graphy-Continuous electric fetal monitoring:CharacterNormalBaseline FHR110-150bpmBaseline variability5-25bpmAcceleration2 in 20 minDecelerationNone or earlyBaseline FHR is the mean level of FHR between the peaks and the depressions in beats per minute (bpm).Baseline variability is the oscillation of baseline FHR excluding the accelerations and decelerations. A base line variability of 5-25 bpm is a sign of fetal wellbeing.Accelerations are increased in FHR by 15 bpm or more lasting for at least 15 secs. Denotes healthy fetus.Deceleration is decrease in FHR below the baseline by 15 bpm or more. Three basic types of deceleration are observed:Early decelerationLate decelerationVariable decelerationType-1 dips.Due to headcompression.Type-ll dips.Due to utero-placentalinsufficiency and fetal hypoxiaIndicates cord compression and may disappear with the change in position of the patient.Pneumonic: (VEAL-CHOP)V- variable decelerationsC- cord compression/ prolapseE- early decelerationsH- Head compressionA- AccelerationsO-OKL- late acceelrationsP-Placental insuffiencyWith each uterine contraction, blood flow to the placenta decreases, and the fetus is exposed to transient hypoxia.As the labor progresses and more and more contractions occur, this hypoxia can eventually lead to a change from aerobic to anaerobic metabolism- fetal acidemia.However, the fetus has a variety of protective mechanisms, including a blood buffering system and the diving reflex (a lowering of the heart rate in times of hypoxic stress), to protect it from becoming dangerously acidemic.Electronic fetal monitoring is not a very specific tool for identifying fetal acidemia.Many fetuses with a non-reassuring fetal heart rate tracing do not have acidemia and are not in distress.However, it can be very difficult to distinguish non-acidemic fetuses with non-reassuring fetal heart rate tracings from acidemic fetuses with non-reassuring fetal heart rate tracings.Thus, the delivery of many fetuses is expedited because of the concern for fetal acidemia when, in fact, the fetus is not acidemic at all.Thus, it is most accurate to state, as is in this case, that the fetus was delivered because of the non-reassuring fetal heart rate tracing.Fetal acidemia is not the reason for delivery. In fact, there is a strong likelihood that this fetus is not acidemic at all.Fetal distress is not the reason for delivery. There is a strong likelihood that this fetus is perfectly healthy and will have high neonatal APGAR scores and no distress at all.Fetal hypoxic encephalopathy is not the reason for delivery. The desire to prevent hypoxic/acidemic damage to organs, including the brain, is the reason for expediting delivery.However, the non-reassuring fetal tracing does not indicate that hypoxic encephalopathy is necessarily occurring.Low neonatal APGAR scores can be a marker of fetal acidemia.However, many fetuses with non-reassuring fetal heart rate tracings do not have low neonatal APGAR scores.
Fetal distress
Fetal acidemia
Fetal hypoxic encephalopathy
Non reassuring fetal heart rate tracing
Miscellaneous (Gynae)