Contemporary practice patterns in the use of amniocentesis for fetal lung maturity^*

Purpose: Fetal lung maturity (FLM) testing has been performed to help direct delivery timing in complex obstetrical conditions. We explored current practice patterns of FLM testing attempting to identify factors affecting its use. Materials and methods: We distributed a 31-question survey to obstetricians and perinatologists that examined practice characteristics potentially affecting FLM usage. Logistic regression measured associations between these factors and test utilization. Weighted averages were calculated for conditions in which respondents considered FLM testing helpful. Results: Three hundred four surveys were completed. The response rate for respondents actively practicing obstetrics was 52%. The majority of respondents utilize FLM testing; however, 80% reported a decline in use over the past five years with 64% citing “published guidelines” as the reason. Respondents found FLM testing most applicable for poorly dated pregnancies. After an immature FLM test, 44% of respondents administer antenatal corticosteroids in the late-preterm period. None of the factors surveyed were significantly associated with FLM testing use. Conclusion: The majority of respondents use FLM testing although significant factors contributing to its use were not identified. We discover a high frequency of antenatal corticosteroid administration beyond 34 weeks gestational age in response to immature FLM indices that may be an area for future study.