By Pat Anson, Editor

We’ve written before about the risks associated with epidural injections used to relieve back pain and pain during childbirth. Now comes word that epidural analgesia may also have adverse effects on newborns.

A large study by researchers at the University of Granada in Spain found that babies born after their mothers were given epidurals had a small decline in their overall health, were less likely to begin early breast feeding, and were significantly more likely to be admitted to neonatal intensive care. Resuscitation was also significantly more frequent in babies born after epidural analgesia.

The study, published in Midwifery magazine, involved over 2,600 babies born between 2010 and 2013 at San Juan de la Cruz hospital in Úbeda, a province of Jaén, Spain

"A series of adverse effects have been observed both on the mother and on the baby,” said lead author Concepción Ruiz Rodríguez, a professor in the Department of Nursing of the University of Granada.

“Adverse effects observed on the baby are attributed to a direct pharmacological effect, due to a placental transmission of the drug administered to the mother, or due to an indirect secondary effect as a consequence to the physiological changes the drug causes in the mother, such as hormonal changes."

Researchers measured the overall health of the babies by using Apgar index values, a quick test applied to newborn babies to assess their general health. They found the Apgar values were “slightly but significantly lower” in newborns whose mothers had epidurals.

“Epidural analgesia may have adverse effects on newborns, although the risks are low, and further research is required to elucidate the causal nature of this relationship,” said Ruiz Rodriguez. "For that, we consider that it's important that both mothers and health professionals (obstetricians and midwives) know and have in mind those risks when the time for taking a decision comes.”

Epidurals involve the injection of steroids, opioids or other analgesic drugs through a catheter. The injection blocks the transmission of pain signals through nerves in the spinal cord.

Epidurals are commonly used to relieve pain during childbirth and, while the risks are low, they can result in complications for the mother such as headaches, difficulty breathing, seizures, or damage to the spinal cord. Drugs used during epidurals also pass through the placenta to the baby.

Epidurals injections are given to millions of Americans each year for back pain and there is growing controversy over their use. A study by federal researchers last year found that steroid injections provide limited or no relief  from radiculopathy and spinal stenosis, two conditions that cause low back pain.

A number of prominent physicians have told Pain News Network the shots are overused, with some patients getting dozens of injections, which raises their risk of complications.