Assessment of Fetal Lung Maturity

Assessment of fetal lung maturity

Authors:Jonathan Gillen-Goldstein, MDAndrew P MacKenzie, MDEdmund F Funai, MDSection Editor:Charles J Lockwood_ MD MHCMDeputy Editor:Vanessa A Barss, MD, FACOG Contributor Disclosures All topics are updated as new evidence becomes available and our peer review process is complete.

Literature review current through: Aug 2017. I This topic last updated: Jun 01, 2017. INTRODUCTION — The pulmonary system is among the last of the fetal

organ systems to mature, both functionally and structurally. Fetal sex and race/ethnicity appear to play a role in this process: respiratory problems near term are more common among white male fetuses than among female

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fetuses, blacks, and South Asians J. Because the immature pulmonary system may not oxygenate the neonate adequately, preterm birth can lead to significant neonatal morbidity or mortality. Therefore, fetal lung maturity is sometimes assessed before iatrogenic preterm delivery and can be a factor in determining the timing of delivery in these cases. Several laboratory tests are available for this purpose. All involve testing amniotic fluid and provide an indirect assessment of the likelihood of lung maturity: direct studies of fetal lung function are not possible. This topic will discuss tests for assessment of fetal lung maturity. Clinical manifestations, diagnosis, treatment, sequelae, and prevention of neonatal pulmonary immaturity are reviewed separately. (See "Pathophysiolociy, clinical manifestations, and diagnosis of respiratory distress syndrome in the newborn" and Prevention and treatment of respiratory distress syndrome in preterm infants" and "Antenatal corticosteroid therapy for

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delivery".) WHEN IS FETAL LUNG MATURITY TESTING PERFORMED? — In most clinical settings. testing for fetal lung maturity is not performed because (1) delaying delivery because of lung immaturity would place the mother or fetus at significant risk, or (2) the fetus would benefit from delaying delivery. even if lung maturity is documented, and delaying delivery does not place the mother at significant risk klj. However, these assessments are not always black and white, and information about lung maturity may sometimes be helpful in the balance (.11. Also. the information may be helpful in estimating the level of newborn care that will be required. Thus, a test for fetal lung maturity may be performed before semielective but medically indicated births