In several posts over the past 18 months we have discussed the neonatal (and, to a lesser, though still significant degree, maternal) risks of “late preterm” or “near term” birth especially when this is done ‘electively’ and by cesarean section prior to the onset of labor. Personally, I have spent the last two years repeating the litany at each of the local hospitals throughout our perinatal region in the Upstate of South Carolina. Recently, recognizing the importance of both patient and provider education as necessary to the success of the campaign, and with the support of the March of Dimes and our State Medicaid Office, we have sent out patient friendly brochures to all providers detailing these risks. Within the past year or so, even the American College of Obstetricians and Gynecologists has taken the firm stance of decrying elective delivery before 39 weeks without medical indication or assessment of fetal lung maturity. So, why am I writing a new post on this subject? Despite the simplicity of the message, not all patients and providers are listening or taking the commandment seriously. “Thou shalt not deliver before 39 weeks, unless thou hast a good indication.”
Ignoring the message is foolish, is associated with increased morbidity for otherwise healthy babies (usually in hospital settings not prepared to handle the unexpected – further increasing the risk of morbidity, mostly respiratory distress), and has gotten to the point where it is indefensible from a medical-legal standpoint. Late preterm birth now constitutes about three-quarters of all preterm deliveries. This amounts to more than 300,000 deliveries per year! Many of these deliveries are by elective cesarean section and many others result from cesarean section as a consequence of failed labor induction when the mother’s cervix is ‘unfavorable.’ Indeed, 50% or more of late preterm inductions end up as cesarean sections. The real tragedy is not in the delivery for appropriate medical indications that results in a baby with complications of prematurity, but the ‘iatrogenic’ prematurity resulting from inaccurate pregnancy dating or marginal medical indications such as “the baby was getting awfully big, her blood pressure was up a little at her last visit, she’s getting a lot of swelling…” and, unfortunately, as many as one-third of all late preterm births are the result of iatrogenic prematurity.
Several recently published articles contribute to the growing body of evidence supporting the concerns related to late preterm birth – whether spontaneous, medically indicated, or iatrogenic. McIntire and Leveno (Obstet Gynecol 2008; 111:35-41) evaluated neonatal outcomes at 34, 35, and 36 weeks of gestation compared with births at 39 weeks. At their institution, late preterm singleton live births accounted for 76% of all preterm births, 45% the result of the late of ‘preterm labor’ and found that ”mortality rates per 1,000 live births were 1.1, 1.5, and 0.5 at 34, 35, and 36 weeks, respectively, compared with 0.2 at 39 weeks (P<.001).” Neonatal morbidity was significantly increased at 34, 35, and 36 weeks, including respiratory distress requiring ventilator support, intraventricular hemorrhage (grades 1 and 2), need for invasive sepsis work-ups, culture-proven sepsis, hyperbilirubinemia, and necrotizing enterocolitis. Shapiro-Mendoza and colleagues (Pediatrics 2008;121:223-32) compared 26,170 infants born late preterm to 377,638 born at term and found that the late-preterm infants were 7 times (22% vs 3%) more likely to have newborn morbidity than term infants. “The newborn morbidity rate doubled in infants for each gestational week earlier than 38 weeks. Maternal medical conditions, especially, maternal hypertensive disorders and hemorrhage increased the vulnerability of the late preterm infants. Yoder and colleagues (Obstet Gynecol 2008;111:814-22) also demonstrated the gestational age-related risk for morbidity and confirmed previous observations that infants delivered by cesarean section fared worse than those delivered vaginally. The article immediately following this one by Yee and colleagues (Obstet Gynecol 2008;111:823-28) supported the relationship of elective cesarean delivery and respiratory complications and also pointed out the increased risk of male infants compared to females born prior to term.
So, what got me off on this tirade today? Well, recently, I visited our neonatal intensive care unit, and there, laid out on a bed designed for the smallest of premature babies, was another 10 lb infant, born at an outside hospital by elective cesarean section at a well-documented “38 weeks.” The baby was clearly macrosomic, had profound hypoglycemia and appeared to be the product of a diabetic mother (although that diagnosis had not been suspected during the pregnancy), was male, and had severe respiratory distress syndrome – indeed, there were real concerns that he might not survive. The sad thing about the case was that the obstetrician had called me about this pregnancy the day before the delivery and asked if it was “alright just to get her delivered by cesarean section because the baby is so big, the patient is miserable, and is begging to be delivered” and I had clearly suggested that an amniocentesis to assess fetal lung maturity be performed first in the absence of any other indication for delivery. It wasn’t done, and I do not know if my recommendation was even mentioned to the patient. I said a little prayer for the baby and, selfishly, for myself, as I left hoping that I would not be called to testify if the outcome was poor in the end….