Term delivery after hospitalization for preterm labor: incidence and costs in california.

Objective: To determine the incidence and costs for cases of idiopathic preterm labor followed by term delivery.Study Design: Patients hospitalized with preterm labor (N = 28,845) were identified in a dataset linking antepartum and delivery discharge abstracts of all women in California (N = 404,466) with a delivery related diagnosis from 1/1/93 to 11/19/93. Patients with multiple gestations, PROM, abruption, placenta previa, uterine anomalies, and other morbidities were excluded, leaving 19,897 study subjects. Birth outcomes were classified as term or preterm (<37 weeks). The incidence, hospital costs, and risk factors for hospitalization for preterm labor followed by term delivery were then determined using a retrospective nested case control design. Indirect costs of subsequent bedrest were estimated using data from the California Disability Insurance Fund.Results: Thirty-four percent of patients hospitalized with idiopathic preterm labor had term deliveries accounting for 2% of the pregnant population. Eighty-one percent of patients who were discharged undelivered after hospitalization delivered at term. These patients were significantly more likely to be Caucasian, privately insured, and older than patients who delivered preterm. A minimum of 45% of cases were estimated to be false diagnoses based on the relative risk of post-dates pregnancy between patients hospitalized with preterm labor and term controls. Costs totalled $4,995 per case with $2,335 in hospital costs and $2,497 in indirect costs from an average of 4 weeks of bedrest. Statewide costs for California were estimated to range from 24 to 48 million dollars annually for these potentially avertible hospitalizations.Conclusions: Hospitalization for idiopathic preterm labor with delivery at term is common, costly, and probably due to false diagnosis in a significant proportion of cases.