Tropical cyclones may be linked to infant mortality in at-risk low- and middle-income countries, new research suggests

Exposure to tropical cyclones could have an impact on young babies' ability to survive in poorer countries, scientists have found.

A mother living through a tropical cyclone while pregnant, or a infant living through a tropical cyclone during the first year of life, may be associated with higher infant mortality when combining data from seven low- and middle-income countries, according to a paper published on Wednesday in Science Advances.

Exposure to cyclones was linked to 4.4 additional infant deaths per 1,000 live births in the aggregate study, which included: Madagascar, India, Bangladesh, Cambodia, the Philippines, the Dominican Republic and Haiti. These countries were studied because they, historically, have a higher risk of tropical cyclones.

Researchers compared tropical wind field data with more than 1.6 million infant survival records. They identified 148,384 babies who were exposed to tropical cyclones in utero or during the first year of life. Most of these babies (109,051) were exposed to tropical storms, which are the weakest type of tropical cyclone.

Bangladesh, the Dominican Republic, and Haiti seemed to generate a higher amount of infantile deaths linked to tropical cyclones -- the 11% increase in infant mortality was mostly driven data from those countries, Zachary Wagner, an associate professor at the University of Southern California's Center for Economic and Social Research and co-author of the paper, told ABC News.

Researchers did not identify a significant impact of tropical cyclones on infant mortality in India, which had the largest number of people exposed to tropical cyclones. They believe that this result may be due to India having better systems in place to handle storms.

The mortality effect on babies seemed to carry over from tropical storm to Category 1 and 2 storms, the researchers said. However, this association was not as pronounced. In the study, they also noted that Category 3 or stronger storms are much rare relative to lower-intensity storms.

However, climate scientists predict that storms will become more extreme in the future due to global warming, which could impact vulnerable populations even more, according to the researchers.

"So there's no reason to expect this to get a lot better over time, but there is reason to expect this to get worse over time," Wagner said.

Wagner was inspired to study the impact of tropical cyclones on infant mortality following his work on how armed conflict impacts pediatric health in war-torn countries for over a decade, he said. He noted that the paper was partially funded by the National Institute of Child Health and Human Development, a part of the National Institute of Health, so the researchers could look into the issue on a large scale.

"We started looking at flooding and tropical cyclones, and we're starting to look at heat and all these big weather events that can have these catastrophic effects in a lot of different areas around the globe," Wagner said.

The effect of being exposed to tropical cyclones, on average, had a similar effect on infant mortality compared to armed conflict, according to Wagner.

"The difference is that there's a lot more armed conflict than there are tropical cyclones, so the overall contribution to child mortality -- the effect is larger," he said.

The article suggested that less baseline vulnerability, better designed structures and better emergency response systems could all contribute to lessening infant mortality influenced by tropical cyclones.

The study did not identify statistical differences, either in individual countries or overall, in hospital antenatal care visits or the number of children being born in health care facilities as a result of tropical cyclones.

"We don't know which of those is actually explaining the difference, though," Wagner said.

"Further research on understanding the mechanisms that are driving these deaths so that we can intervene in an effective way is necessary," Wagner said.

In the future, the researchers will also be looking into how other vulnerable populations in the U.S., such as the elderly, can be affected by tropical cyclones -- such as disruptions in medication use or access to healthcare facilities for preventative care, he added.