According to an investigation in the December 7 issue of JAMA, antenatal (before birth) corticosteroid therapy for mothers who delivered their infants between 23 to 25 weeks’ gestation appeared to lower infant death rate or neurodevelopmental impairment at 18 to 22 months of age.

The researchers explain:

“Current guidelines, initially published in 1995, recommend antenatal corticosteroids for mothers with preterm labor from 24 to 34 weeks’ gestational age, but not before 24 weeks due to lack of data. However infants born before 24 weeks’ gestation are provided intensive care.”

Waldemar A. Carlo, M.D., of the University of Alabama at Birmingham, and colleagues set out to investigate if antenatal corticosteroid exposure in extremely premature infants lead to an improvement in death and neurodevelopmental impairment outcomes at 18 to 22 months. The investigation included data on infants born at 23 academic perinatal centers in the U.S., at 22 to 25 weeks’ gestation between January 1993 and December 2009 with a birth weight between 401 grams (14.1 ounces) and 1,000 grams (35.3 ounces) (n=10,541). 7,808 (74.1%) of these infants were born to mothers who received antenatal corticosteroids. 4,924 (86.5%) of the 5,691 infants born between 1993-2008, who survived 18 to 22 months had neurodevelopmental evaluations.

The team discovered that the death rate or neurodevelopmental impairment was lower in infants born at 23, 24 and 25 weeks’ gestation whose mothers received antenatal corticosteroids (83.4%, 68.4%, and 52.7%) than infants without exposure (90.5%, 80.3% and 67.9%) However, in infants born at 22 weeks’ gestation the death or neurodevelopmental impairment was comparable (90.2% versus 93.1%).

The researchers write:

“If the mothers had received antenatal corticosteroids, the following events occurred significantly less in infants born at 23,24, and 25 weeks’ gestation: death by 18 to 22 months; hospital death; death, intraventricular hemorrhage, or periventricular leukomalacia [a type of brain injury]; and death or necrotizing enterocolitis [a condition in which part of the tissue in the intestines is destroyed].

For infants born at 22 weeks’ gestation, the only outcome that occurred significantly less was death or necrotizing enterocolitis (73.5 percent with exposure to antenatal corticosteroids vs. 84.5 percent without exposure).”

Although the investigators warn:

“even though intact survival doubled with the administration of antenatal steroids in the entire cohort, it remained relatively low (36 percent).”

They researchers conclude:

“Despite their potential to improve outcomes, the administration of antenatal corticosteroids is not increasing at gestational ages around the limits of viability and remains substantially lower that at later gestational ages. Controlled trials could be performed to precisely determine the benefits of antenatal corticosteroids when administered this early but such trials will be difficult to perform. Initiation of antenatal corticosteroids may be considered started at 23 weeks’ gestation and later if the infant will be given intensive cause because this therapy is associated with reduced mortality and morbidity.”

Written by Grace Rattue