When pregnant women are at risk for having a premature birth, prenatal steroids appear to help. The steroids seem to improve survival rate and limit brain injury in infants born as early as 23 weeks of pregnancy.
With the full term of pregnancy being 40 weeks, infants born preterm in the 22nd through 25th week of pregnancy are the smallest and most fragile category of newborns.
But prenatal steroids could help them.
A research team at the Neonatal Research Network of the National Institutes of Health analyzed the medical records of about 10,500 infants born prematurely between 1993 and 2009. Researchers also performed neurological exams on the 4,924 of those infants who survived, conducted 18-22 months after their original due date.
Prior studies have shown that steroids improve a baby’s lung maturation and reduce problems such as respiratory distress. In 1995, NIH published a statement on the use of antenatal steroids for mothers with the threat of preterm delivery, and recommended them between 24 and 34 weeks of pregnancy.
But before this most recent study, there was little information available to guide the medical community in the use of prenatal steroids before the 24th week of pregnancy.
“When the physicians admitted the steroids to the mothers before the baby was born, overall in the whole group study from 22 to 25 weeks, there was an improved survival rate as well as the neurodevelopmental outcome at 18 to 22 months,” said Dr. Rosemary Higgins, a board-certified neonatologist at NIH.
Dr. Higgins said that the findings provide strong evidence that prenatal steroids can benefit infants born as early as the 23rd week of pregnancy.
This is encouraging news, because such early term babies often die soon after birth, despite the most sophisticated newborn care available. For those who survive, some reach adulthood relatively unaffected while others experience some degree of lifelong disability including cerebral palsy, intellectual disability and minor hearing loss.
Based on the previous steroid recommendations before this most recent study, Dr. Higgins said that some physicians would not offer steroids at less than 24 weeks of pregnancy.
“However some physicians felt that if there could potentially be a benefit they would give steroids.”
The study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Findings were published in a recent issue of the Journal of the American Medical Association.
Over 3 percent (1 out of 33) babies born in the United States has some kind of birth defect. Many are genetic and could not have been prevented, as the cause of up to two thirds of all birth defects are unknown. However, many common birth defects are also preventable. The focus of prenatal care is to ensure that mother and baby are both healthy during pregnancy, as well as preventing and treating any looming birth defects and health problems.
The most common preventable birth defects are cardiac (1 out of every 100-200) which can range from common defects of the inner walls of the heart to very severe arterial problems that require emergency surgery or transplants. Also common are neural tube defects (1 out of every 1000) which commonly result in spina bifida (a defect of the spinal cord) and anencephaly (incomplete formation of the brain. These are less common but serious problems that can result in significant sickness and death for the child. While rare, genetic defects in utero can result in several different genetic disorders, including Down’s syndrome, Prader-Willi syndrome, Turner’s syndrome, and many others.