EXPERT COMMENTARY
Pregnancy management when delivery appears to be imminent at 22 to 26 weeks’ gestation—a window defined as the periviable period—is among the most challenging situations that obstetricians face. Expert guidance exists both at a national level in a shared guideline from the American College of Obstetricians and Gynecologists and the Society of Maternal Fetal Medicine and, ideally, at a local level where teams of obstetricians and neonatologists have considered in their facility what represents best care.1 But whether national or local, such consensus is largely expert opinion based on a foundation limited by available evidence, which is almost always retrospective analysis of rare cases.
Among the most important yet often missing data points are outcomes of neonates born in the periviable period. Surveys suggest that obstetric care providers often underestimate the chance of survival following periviable delivery.2 Understanding and weighing anticipated outcomes inform decision making regarding management and planned obstetric and neonatal interventions, including plans for neonatal resuscitation.
Not surprisingly, perhaps, survival of periviable neonates has been linked clearly to willingness to undertake resuscitation.3 Yet decisions are not and should not be all about survival. Patients and providers want to know about short- and long-term morbidity, especially neurologic health, among survivors. Available collections of morbidity and mortality data, however, often are limited by whether all cases are captured or just those from specialized centers with particular management approaches, which outcomes are included and how they are defined, and the inevitable reality that the outcome of death “competes” with the outcome of neurologic development (that is, those neonates who die are not at risk for later abnormal neurologic outcome).
Given the need for more and better information, the data from a recent study by Younge and colleagues is especially welcome. The investigators reported on survival and neurologic outcome among more than 4,000 births between 22 and 24 weeks’ gestation at 11 centers in the United States.
Details of the study
The authors compared outcomes among three 3-year epochs between 2000 and 2011 and reported that the rate of survival without neurodevelopmental impairment increased over this period while the rate of survival with such impairment did not change. This argues that the observed overall increase in survival over these 12 years was not simply a tradeoff for life with significant impairment.
Within that overall message, however, the details of the data are important. Survival without neurodevelopmental impairment did improve from epoch 1 to epoch 3, but just from 16% to 20% (95% confidence interval [CI], 18–23; P = .001). Most neonates in the 2008–2011 epoch died (64%; 95% CI, 61–66; P<.001) or were severely impaired (16%; 95% CI, 14–18; P = .29). This led the authors to conclude that “despite improvements over time, the incidence of death, neurodevelopmental impairment, and other adverse outcomes remains high.” Examined separately, outcomes for infants born at 22 0/7 to 22 6/7 weeks’ gestation were very limited and unchanged over the 3 epochs studied, with death rates of 97% to 98% and survival without neurodevelopmental impairment of just 1%. In my own practice I do not encourage neonatal resuscitation, cesarean delivery, or many other interventions at less than 23 weeks’ gestation.
By contrast, the study showed that at 24 0/7 to 24 6/7 weeks’ gestation in the 2008–2011 epoch, 55% of neonates survived and, overall, 32% of infants survived without evidence of neurodevelopmental impairment at 18 to 22 months of age.
Related Article:
Is expectant management a safe alternative to immediate delivery in patients with PPROM close to term?
Study strengths and weaknesses
It is important to note that the definition of neurodevelopmental impairment used in the Younge study included only what many would classify as severe impairment, and survivors in this cohort “without” neurodevelopmental impairment may still have had important neurologic and other health concerns. In addition, the study did not track outcomes of the children at school age or beyond, when other developmental issues may become evident. As well, the study data may not be generalizable, for it included births from just 11 specialized centers, albeit a consortium accounting for 4% to 5% of periviable births in the United States.
Nevertheless, in supporting findings from other US and European analyses, these new data will help inform counseling conversations in the years to come. Such conversations should consider options for resuscitation, palliative care, and, at less than 24 weeks’ gestation, pregnancy termination. In individual cases these and many other decisions will be informed by both specific clinical circumstances—estimated fetal weight, fetal sex, presence of infection, use of antenatal steroids—and, perhaps most important, individual and family values and preferences. Despite these new data, managing periviable gestations will remain a great and important challenge.
Although there have been small improvements with time, the risk of death or significant neurodevelopmental impairment with delivery in the periviable period remains high and, at less than 23 weeks' gestation, is nearly universal. This finding emphasizes the importance of shared decision making, incorporating individual and family preferences and values. In addition to planned resuscitation, options to be discussed should include palliative care and, at appropriate gestational ages, the possibility of pregnancy termination.
--Jeffrey L. Ecker, MD
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