Does corticosteroid therapy impact fetal pulmonary artery blood flow in women at risk for preterm birth?

Abstract

Aim: Maternal corticosteroid administration in pregnancy is known to enhance fetal lung maturity in at risk fetuses. The aim of this study was to test the hypothesis that corticosteroid therapy alters fetal pulmonary blood flow in pregnancies at risk for preterm birth (PTB). Material and methods: We prospectively evaluated main fetal pulmonary artery (MPA) blood flow in pregnant women at risk for PTB and treated with corticosteroids (betamethasone), compared to an uncomplicated cohort without steroid therapy. The Doppler indices of interest included Peak Systolic Velocity (PSV), Resistive Index (RI), Pulsatility Index (PI), Systolic/Diastolic ratio (S/D ratio), Acceleration Time (AT), and Acceleration Time/Ejection Time Ratio (AT/ ET ratio), with the latter serving as the primary outcomes due to its stability irrespective of gestational age. Results: When compared with controls, fetuses treated with corticosteroids demonstrated significantly decreased pulmonary artery acceleration time (median: 28.89 (22.22-51.11) vs. 33.33 (22.20-57.00), p=0.006), while all other indices remained similar. We found no difference in pulmonary blood flow between fetuses who developed respiratory distress syndrome (RDS) and those that did not (31.56 ± 6.842 vs. 32.36 ± 7.265, p= 0.76). Conclusion: Our data demonstrate altered fetal pulmonary blood flow with corticosteroid therapy, possibly due to increased arterial elastance brought on by medication effect, which leads to the decreased acceleration time or possible gestational age affect. Contrary to a recent report, we did not observe any Doppler differences in fetuses with RDS, which underscores the need for further examination of this proposed association.

Effect of Betamethasone on Fetal Pulmonary and Umbilical Artery Doppler Velocimetry and Relationship With Respiratory Distress Syndrome Development

“…We evaluated the impact of steroid therapy on fetal PA and UA indices and whether there was a difference in the fetuses who developed RDS and those who did not. Similar to Lindsley et al, 15 we did not find a statistically significant difference in pulmonary blood flow between fetuses who developed RDS and those who did not. Also, Kim et al 5 reported that there were no significant differences in PA PI and RI scores between fetuses who developed RDS and those who did not.…”

Reproductive disorders in female rats after prenatal exposure to betamethasone

“…This increase provides a critical developmental trigger, one that is essential for normal maturation of the fetal lung and developmental switching in many other organ systems, including the thyroid, kidney, brain and pituitary (Fowden & Forhead, 2004;Moisiadis & Matthews, 2014). Pregnant women at risk of preterm delivery need to be treated with exogenous glucocorticoids to promote the same results as in the normal intrauterine conditions for fetal development (Gyamfi-Bannerman et al, 2016;Lindsley et al, 2015).…”

“…Betamethasone (BM), a synthetic glucocorticoid, is considered the glucocorticoid of choice for this antenatal treatment (Alexander et al, 2016;Lindsley et al, 2015) being used for pregnant women between 24 and 34 weeks of gestation ( Jobe & Soll, 2004;Rayburn et al, 1997;Wapner, 2013), promoting fetal lung maturation and thus reducing the incidence of respiratory distress syndrome, neonatal mortality and morbidity (Gyamfi-Bannerman et al, 2016;Lindsley et al, 2015). However, the prenatal exposure to BM demonstrated several systemic long-term deleterious effects on offspring in different experimental protocols (Alexander et al, 2016;Belanoff et al, 2001;Bertram & Hanson, 2002;Pascual et al, 2014;Su et al, 2015).…”

Adverse effect of dexamethasone on development of the fetal rat ovary

“…Endogenous glucocorticoids are essential for normal maturation of the fetal brain and lung as well as developmental switching in the pituitary, thyroid gland, and kidney . When the risk of preterm delivery persists, a pregnant woman needs to be treated with exogenous glucocorticoids to promote differentiation and maturation of fetal organ systems and to mimic normal intrauterine conditions . Moreover, glucocorticoid application is routine in the prevention and management of conditions that threaten maternal and fetal health, such as maternal asthma and autoimmune diseases . Dexamethasone (Dx) is considered to be the glucocorticoid of choice for antenatal therapy .…”