We appreciate the thoughtful reading of our work by Drs Lappen and Myers. We are glad that they found useful our calculation of the risk of stillbirth using the denominator of ongoing pregnancies. Understanding this prospective fetal mortality risk is crucial to estimating the mortality risks that are associated with expectant management at term. However, mortality risks do not disappear once delivery is achieved. In evaluating the risks of expectant management in comparison with those faced by the fetus once delivered, we consider the gestational age-specific risk of infant death. Using infant mortality rates that are calculated with the denominator of all live births at each gestational age, we can use this metric to represent the gestational age–dependent mortality risk faced by the newborn infant within the first year of life. As Lappen and Myers note, we are not the first to demonstrate that infant mortality rate varies by gestational age at term. We disagree that this is solely due to an increasing denominator, because we and others report rates calculated per 10,000 live births at each gestational age.

Although it is more difficult to intuit the reasons that infant death caused by such events as sudden infant death syndrome, pneumonia, and influenza would be associated with gestational age at term, this has been demonstrated in the literature. The association of these late-onset pulmonary complications may be the consequence of the short-term respiratory complications now known to be associated with early-term birth. We specifically chose to use infant death instead of neonatal death because, at term, the proportion of death that occurs after 28 days is not insignificant and because it has been associated with the week of gestation at term. Ultimately, a patient who experiences a fetal, neonatal, or infant death cares less about the exact timing than the loss of their child. Especially among African American parents, who have a high risk of both stillbirth and infant death, understanding this relationship is important if an early delivery is considered with the intent to decrease mortality rates.

We hope our findings continue to encourage discussion towards the determination of the best gestational age for delivery at term and more research into the risk factors and pathophysiologic causes of stillbirth and infant death at term.