Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong--and What You Really Need to Know

Oster explores the anxiety surrounding preterm birth, offering evidence-based clarity on survival rates, medical interventions, and the contested role of bed rest. Drawing from personal experience and statistical data, particularly US Natality Detail Files from 2005, Oster outlines how survival outside the womb improves dramatically with each passing week after 22 weeks. By 28 weeks, survival rates exceed 90%, and by 34 weeks, they near 99%. She explains how even short delays in labor allow for critical interventions: steroid shots to accelerate fetal lung development and transfers to higher-level NICUs. These improvements reflect broader advances in neonatal medicine since the 1960s, contextualized through historical examples like the death of John F. Kennedy’s son in 1963.

Oster then turns a critical eye to the routine prescription of bed rest for threatened preterm labor. Citing randomized controlled trials and multiple systematic reviews, she asserts that bed rest lacks efficacy and carries significant risks, ranging from bone loss and muscle atrophy to family disruption and economic strain. Despite a 2009 survey revealing that most OBs privately doubt its benefit, the majority still recommend it. This contradiction highlights a disjunction between medical evidence and clinical practice.

Oster’s background as an economist shapes her evidence-first approach, and this chapter exemplifies her commitment to scrutinizing widely accepted practices through rigorous data.