Performance of lecithin-sphingomyelin ratio as a reflex test for documenting fetal lung maturity in late preterm and term fetuses

Corina Tennant, Alexander M. Friedman, Emmanuelle Pare, Christie Bruno, Eileen Wang

Research output: Contribution to journalArticle

9 Scopus citations


Objective: To determine if infants delivered after immature or indeterminate TDx-FLM II testing and a mature reflex test are at increased risk for neonatal respiratory complications. Methods: The primary analysis compared neonatal respiratory morbidity (RDS or TTN) in 34-39-week fetuses delivered after either (i) mature TDx-FLM II testing, or (ii) indeterminate or immature TDx-FLM II and a positive reflex test (PG or L/S ratio). Results: Fifty patients delivered after mature TDx-FLM II, and 30 after immature or indeterminate TDx-FLM II with an L/S ≥2.0. Respiratory morbidity was significantly higher in the group delivered after mature reflex testing compared with mature TDx-FLM II (23% vs. 2%, p < 0.01). When PG was present, there were no cases of RDS or TTN. Conclusions: Utilizing L/S ratios as a reflex test to confirm lung maturity was associated with a high risk for respiratory morbidity, particularly when PG was not present.

Original languageEnglish (US)
Pages (from-to)1460-1462
Number of pages3
JournalJournal of Maternal-Fetal and Neonatal Medicine
Issue number8
Publication statusPublished - Aug 1 2012



  • LS ratio
  • cascade testing
  • lung maturity testing

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Obstetrics and Gynecology

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