“RECOMMENDATIONS FOR PERINATAL CARE HAVE A TROUBLING PEDIGREE”
ROBERT L. BARBIERI, MD (EDITORIAL, APRIL 2009)
I appreciated Dr. Robert L. Barbieri’s thoughtful response to the rigid guidelines promulgated by the National Quality Forum (NQF). The source of much confusion about these guidelines, which advise against elective cesarean delivery prior to 39 weeks’ gestation, is the flawed, recent article in the New England Journal of Medicine regarding the alleged risks of elective term cesarean delivery.1 As a faculty obstetrician for a high-risk, indigent, safety-net population, I have more than a passing interest in this topic. I must counsel and schedule these patients for “elective” repeat cesarean delivery on a routine basis.
My concern is not that 39 weeks is an unreasonable generic target; it is that the subject is nuanced. There is likely some modest, transient neonatal risk during the 37th week of gestation that significantly diminishes during the 38th week—but these risks must be balanced against the benefit of scheduled cesarean delivery without labor. As Dr. Barbieri noted, the quality of evidence asserting risk is lacking, a fact that often gets lost in the rush to mandate medicine by protocol.
I offer the following points:
- If a study does not accurately date the pregnancies of its participants by means of early transvaginal ultrasonography (US), it should not make firm pronouncements regarding gestational age and related outcomes. The aforementioned study fails in this regard.1 Furthermore, accurate US dating, on average, produces an earlier gestational age. As a result, a gestational age of 39 weeks may sometimes represent an otherwise well-dated 38-week gestation.
- The NEJM study was further biased by differences between women at 38 weeks’ and 39 weeks’ gestation on the bases of ethnicity and smoking, both of which are known to affect fetal lung maturation.1
- Some studies demonstrate little or no risk during the 38th week.
- The literature suggests that 1) all morbidity at term is transient, without any long-term sequelae, and 2) during the 38th week, any increase in respiratory morbidity is minimal and likely represents transient tachypnea of the newborn—not true respiratory distress syndrome (RDS).
- Amniocentesis carries risk and expense but no proven benefit at term.
- Unscheduled cesarean delivery in general has a significantly poorer outcome than scheduled repeat cesarean delivery for both the newborn and the parturient, and the risk increases the longer the cesarean is delayed. If the patient is in labor, her risk of uterine rupture rises from essentially zero to the quoted figure of 0.7% or higher. Approximately 10% of women scheduled to undergo cesarean delivery during the 39th week will require an unscheduled repeat cesarean earlier.
- There is no physiologic basis for the argument that cesarean delivery at 38 weeks and 5 days is “risky” but magically “safe” 2 days later.
- The risk of stillbirth or fetal demise is very real during the 38th week.
These issues should be taken into consideration by the OB (especially when resources are limited) and should enter into counseling of the patient. Ultimately, the decision should be made by the patient in consultation with her physician, not under threat of “protocol noncompliance” or peer review.
Kenneth W. Elkington, MD
North Colorado Family Medicine Residency
Dr. Barbieri responds:
I deeply appreciate Dr. Elkington’s letter. It is far wiser than my original editorial! He concisely and convincingly argues that our key focus should remain on the needs of our patients, not rigid guidelines that are based on evidence from observational studies.