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Effect of interval from fetal corticosteroid treatment to delivery on postnatal lung function of preterm lambs

Version 2 2024-06-13, 15:30
Version 1 2022-03-29, 15:45
journal contribution
posted on 2024-06-13, 15:30 authored by M Ikegami, DH Polk, AH Jobe, J Newnham, P Sly, R Kohan, R Kelly
The effect of altering the interval from treatment to delivery on postnatal lung function of the preterm lamb is unknown. We treated groups of 8-10 singleton fetal sheep with 0.5 mg/kg betamethasone by fetal injection and evaluated postnatal lung function 40 min after preterm delivery at 123 days gestation 2 days after treatment or at 128 days gestation 2, 4, and 7 days after treatment relative to groups of 4-8 saline-injected control animals. At 123 days, betamethasone significantly improved arterial PCO2, dynamic thoracic compliance, and ventilatory efficiency index and doubled lung gas volume relative to a control group. Fetal treatment with betamethasone 2, 4, or 7 days before delivery at 128 days also improved these same indicators of lung function relative to controls, and the magnitude of the improvements was the same for all indicators and independent of treatment-to-delivery interval. Betamethasone suppressed the normal postnatal increase in plasma cortisol after 2 and 4 days of exposure but not after 7 days of exposure. Betamethasone also increased fetal and postnatal triiodothyronine concentrations after 2 days of exposure but not at 4 or 7 days of exposure. Although the hormone effects were transient, postnatal lung functional responses to betamethasone persisted over the 2- to 7-day interval from treatment to delivery.

History

Journal

Journal of Applied Physiology

Volume

80

Pagination

591-597

Location

United States

ISSN

8750-7587

eISSN

1522-1601

Language

English

Publication classification

C1.1 Refereed article in a scholarly journal

Issue

2

Publisher

AMER PHYSIOLOGICAL SOC

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