Amnioinfusion, fetal scalp electrodes, intrauterine pressure catheters: tools for intervention in labor & delivery
Each of these tools are illustrated below.
I’m wrapping up the series on fetal monitoring, discussing specific interventions for fetal heart abnormalaties that might indicate fetal stress or, even more importantly, fetal distress. Let’s take them categorically.
ACCELERATIONS (heart rate increasing above baseline). Usual cause: normal response and, unless prolonged, requires no intervention. Stimulating fetal scalp should cause acceleration and can be used clinically to reassure fetal well-being.
EARLY DECELERATIONS (gradually slowing of the baby’s heart simultaneous with peak of contractions). Usual cause: head compression; uterus pushing baby down the birth canal puts pressure on the head. This is a normal response and usually requires no specific intervention.
VARIABLE DECELERATIONS (sharp downward spike in heart rate simultaneous with peak of contraction). Usual cause: umbilical cord compression; the cord serves as the baby’s life line, repeated variable decelerations require intervention. Intervention: most often repositioning mom does the trick. If position change fails to remedy the situation supplemental oxygen and/or amnioinfusion (see above) may be utilized.
LATE DECELERATIONS (slowing of fetal heart below baseline that comes after the peak of the contraction). Usual cause: often not clear, necessitating exploration of possible factors – infection, maternal blood loss from any cause, reduced amniotic fluid; intense, frequent contractions; or dehydration. Intervention: as determined by analysis – change positions, treat infection; obtain ultrasound to diagnose blood loss, fetal position or reduced amniotic fluid; start amnioinfusion, stop Pitocin if augmenting contractions, give intravenous fluids; attach fetal scalp electrode and/or insert intrauterine pressure catheter (see above) to improve accuracy of monitoring.
PROLONGED LATE DECELERATIONS (similar to late decelerations, but lasting greater than one minute or longer). Usual cause: same as late decelerations, but more ominous requiring aggressive diagnosis and intervention to include preparations for possible emergency cesarean section.
One final word. Labor and delivery is a team sport often requiring the expertise of multiple caregivers – nurses, anesthesiologists, midwives, maternal-fetal medicine consults, and newborn baby specialists to ensure the goal of a healthy, happy baby.