Expert Commentary
Is neonatal injury more likely outside of a 30-minute decision-to-incision time interval for cesarean delivery?
Not according to this study.
Although a timely delivery is always desirable, it may not always be possible to achieve safely due to intrinsic patient characteristics or situational constraints.
CASE 1: Term delivery: 45 minutes from decision to incision
P. G. is a 27-year-old woman (G2P1) at 38.2 weeks’ gestation who presents to the labor and delivery unit reporting painful contractions after uncomplicated prenatal care. She has a body mass index (BMI) of 40 kg/m2. Upon admission, her fetal heart-rate (FHR) tracing falls into Category 1. An examination reveals a cervix dilated to 4 cm and 70% effaced. Epidural analgesia is administered for pain control.
After 4 hours, the FHR tracing reveals minimal variability with occasional variable decelerations. The obstetrician is informed but issues no specific instructions. After 2 more hours, the FHR tracing lacks variability, with late decelerations and no spontaneous accelerations—a Category 3 tracing, which is predictive of abnormal acid-base status. Contractions occur every 3 to 4 minutes.
When fetal scalp stimulation by the nurse fails to elicit any accelerations, intrauterine resuscitation is attempted with an intravenous fluid bolus, left lateral positioning, and oxygen administration. Despite these measures, the FHR pattern fails to improve.
Although she is apprised of the need for prompt delivery, the patient hopes to avoid cesarean delivery, if possible, and insists on more time before a decision is made to proceed to cesarean. After another 2 hours, the FHR pattern has not improved and cervical dilation remains at 4 cm. The patient gives her consent for cesarean delivery.
Approximately 35 minutes are needed to take the patient to the operating room (OR). About 45 minutes after informed consent, the incision is made. Forty-seven minutes later, a male infant is delivered with Apgar scores of 1, 3, and 4 at 1, 5, and 10 minutes, respectively. Umbilical arterial analysis reveals a pH level of 6.9, with a base excess of –21. The infant has a neonatal seizure within 3 hours and is eventually diagnosed with cerebral palsy.
A claim against the clinicians alleges that deviation from the “standard of care 30-minute rule more than likely caused” hypoxic ische- mic injury and cerebral palsy.
Does the literature support this claim?
Approximately 3% of all births involve cesarean delivery for a nonreassuring FHR tracing.1 Much has been written about the “30-minute rule” for decision to incision time. In this article, we highlight current limitations of this standard in the context of 4 distinct clinical scenarios.
Case 1 highlights several limitations and ambiguities in the obstetric literature. Although a timely delivery is always desirable, it may not always be possible to achieve safely due to intrinsic patient characteristics or situational constraints. Conditions prevailing before the decision to proceed to cesarean delivery also affect overall pregnancy outcomes. Not all cases have the same starting point; fetal status at the time of the cesarean decision also determines the acuity and urgency of the case.
A widely promulgated rule— but is it valid?
Both the American College of Obstetricians and Gynecologists (ACOG) and the Royal College of Obstetricians and Gynaecologists have published guidelines stating that any hospital offering obstetric care should have the capability to perform emergent cesarean delivery within 30 minutes.2,3 This general statement has been touted as the standard by which obstetric services should be evaluated. Regardless of the clinical situation, obstetric providers are expected to abide by this rule.
These guidelines recently have come under scrutiny. For example, a 2014 meta-analysis involving more than 30 studies and 22,000 women revealed that only 36% of all cases with a Category 2 FHR tracing were delivered within 30 minutes.4 Interestingly, investigators reported that infants with a shorter delivery interval had a higher likelihood of having a 5-minute Apgar score below 7 and an umbilical artery pH level below 7.1, with no difference in the rate of admission to a neonatal intensive care unit (NICU) when the time from decision to delivery was examined.4 This finding highlights the questionable nature of the current clinical standard, as well as the conflicting findings currently present in the literature.
In general, patients who have graver clinical findings will be delivered at a shorter interval but may still have worse neonatal outcomes than infants delivered 30 minutes or more after the decision for cesarean is made.
Although Case 1 is complicated by FHR abnormalities, the association between such abnormalities and adverse long-term outcomes in neonates is questionable. Fewer than 1% of cases involving late decelerations or decreased variability during labor lead to cerebral palsy,5 highlighting the weak association between FHR abnormalities and neurologic sequelae. Most adverse neurologic neonatal outcomes are multifactorial in nature and may not be attributable to a single prenatal event.