New York, Mar 15 (IANS): A drug commonly prescribed to pregnant women with a history of delivering premature babies may do more harm than good, says a study.

Far from providing any benefit, this drug -- known by the brand name Makena -- may even increase the risk of developing gestational diabetes, said the study published online in the American Journal of Obstetrics and Gynecology.

"Our study showed the drug to be ineffective, and it has a side effect," said first author of the study David Nelson, Assistant Professor of Obstetrics and Gynecology at University of Texas Southwestern Medical Center (UT Southwestern) in the US.

The drug, a synthetic progestogen hormone called 17-alpha hydroxyprogesterone caproate, was approved by the US Food and Drug Administration (FDA) in 2011 to treat women at risk of delivering a second premature baby.

The FDA gave the drug accelerated approval in part due to findings in a 2003 study published in The New England Journal of Medicine that the drug reduced the likelihood of a repeat preterm delivery.

However, Makena has been a source of debate among doctors because of the questions raised about the 2003 findings.

Earlier research findings on the benefit of 17-OHPC have been mixed, said Kenneth Leveno, senior author of the study and Professor of Obstetrics and Gynecology at UT Southwestern.

In the newly published study, pregnant women treated at Parkland Memorial Hospital, were offered the drug 17-alpha hydroxyprogesterone caproate (17-OHPC) if they had a prior history of premature births and were carrying a single fetus.

The research took place from 2012 to 2016 and followed 430 women treated with the drug.

Researchers then compared the premature birth rate of those women with the historical premature birth rate of 5,787 patients seen at Parkland between 1988 and 2011 -- women who also had a history of premature delivery but never took the drug.

Of the women in the study group who took the drug, 25 per cent had a premature delivery.

That compared with a 16.8 per cent preterm birth rate in the historical nondrug group.

The rate of gestational diabetes was 13.4 per cent in women treated with the drug, compared with eight per cent in the other group, the study found.

Gestational diabetes often goes away after the birth, and therefore is not usually a serious problem for the mother, Nelson said.

However, it can lead to deliveries of larger babies and increased chances for cesarean sections and other birth complications.