Confused by the 3rd Presidental Debate? What is peri-viable birth?

By Eva Martin, MD of Elm Tree Medical, Inc.

After the third presidential debate, you may have left scratching your head: what exactly are “partial births”? The Society for Maternal Fetal Medicine and the American College of Obstetricians and Gynecologists recently published a consensus statement on “periviable birth,” which are births between 20 and 25 weeks gestation. Read on to learn exactly why birth at this age is controversial and what interventions are recommended and not. (For the record, I am just assuming that’s what the candidates were discussing. I could be wrong!)

Although birth at these very early gestational ages is very rare (0.5% of all births), they are the major cause of neonatal death. Even taking into account all infant deaths, periviable birth still causes 40% of deaths. What exactly is periviable birth? Starting at 20 weeks of pregnancy through the last day of the 25th week of pregnancy, doctors consider any birth “periviable” because outcomes are so uncertain. Only a few decades ago, newborns born so early could not survive.

Thanks to some tremendous advances in neonatal medical care, more and more of these infants are able to survive. Only about 5% of infants born before 23 weeks live, but up to 67-76% of infants born in the 25th week survive. Each extra day in utero tends to correlate with better chances. Here is an easy-to-read graph showing the survival rates for infants born in the periviable period, by completed week of pregnancy.

Unfortunately, even those babies who survive, often go on to suffer from severe, lifelong complications such as cerebral palsy, cognitive delay, blindness, and hearing loss. At 30 months of age, 17-45% of infants who survive have moderate to severe impairments. At 4-8 years of age, 24-43% of infants have moderate-to-severe neurodevelopmental impairment.

Parents facing a birth before the third trimester are dealing with one of the most difficult and heart-wrenching situations imaginable. Counseling patients on their options is the most important step in constructing a care plan. Sadly, a mother’s health is often also at risk, as is the case with preeclampsia, abruption, or infection.

The NICHD developed an online tool for clinicians to estimate the odds of outcomes for infants born in the periviable stage, to better assist patients in making informed decisions about their health and their infant’s health. The calculator estimates outcomes for all live births and for all infants who undergo resuscitation with mechanical ventilation. The calculator is limited, however. The data is from 1998-2003 and thus doesn’t take into account the latest advances in neonatal medicine. These population-based models also cannot predict the outcome for any one individual with certainty.  Finally, some of the inputs are imprecise, such as estimated fetal weight based on ultrasound and the gestational age in completed weeks (not days). Most importantly, the calculator does not take into account personal values.

You may wonder why outcomes on the calculator are separated into two groups. Patients have the choice to prioritize comfort for their infant and to minimize suffering or to prioritize survival and undergo aggressive resuscitation (or anything in between). According to SMFM and ACOG and the American Academy of Pediatrics, “parents should be given the choice for palliative care alongside the option to attempt resuscitation.” A family’s goals are the most important factor in determining what action is best. It’s also important to remember that goals can change over time (for instance, as the clinical scenario changes or the odds of certain outcomes change over time). Frequent re-evaluation is necessary.

What tools do obstetricians have to improve outcomes in the face of a periviable birth? Family counseling and transfer to a hospital with Level III-IV NICU and Level III-IV maternal care are the first steps. Other interventions include: antenatal corticosteroids for fetal lung maturity, magnesium sulfate for neuro-protection, latency antibiotics after PPROM, and “rescue” cervical cerclage in some cases. Learn more about each one here.

We want to hear from you. Have you had patients face this terrible scenario? How do you best council them?