Obesity and teen pregnancy rates are both unusually high in South Los Angeles compared to the rest of the county, and a new study says one may make the other more likely.

Research appearing in the American Journal of Obstetrics & Gynecology says teen mothers are significantly more likely to be obese or overweight later in life than women who didn't give birth as teens, making it one of the first studies to name teen pregnancy as a predictor of obesity.

In a statement, lead author Dr. Tammy Chang said teen mothers often have so many "immediate concerns"—caring for their children; having a place to live; continuing their education—"that we don't often think of the long term health effects of teen pregnancy."

Chang and her co-authors found that women who'd first given birth between the ages of 13 and 19 were 32 percent more likely to become obese than women who'd first given birth later than that. To better pinpoint why that is, they said, more research will be necessary.

In South L.A., about 1 in 3 adults is obese; data from the L.A. County Department of Public Health indicates that the area sees nearly 59 teen births for every 1,000 teenage girls.

Dr. Gonzalo Garreton—who works with teen mothers as an OB/GYN at Kaiser Permanente South Bay Medical Center—has some ideas as to why the new study may have found the two to be related.

"When you look at the demographics, they're clearly of a lower economic group," said Garreton.

Teen moms are usually "uninsured or poorly insured" and often leave their education temporarily "if not for good,"he said.

Broadly speaking, the factors that drive up teen pregnancy rates can converge with others to create an environment where a healthy lifestyle is difficult to achieve: poor understanding of health in general; poor access to healthy food; few places to exercise; and little access to health care.

The combination can makes obesity more likely, as well as the some dangerous conditions: diabetes, high blood pressure, sleep apnea.

Add to that the fact that the "vast majority" of teen pregnancies are unplanned, said Garreton, and the situation can quickly become overwhelming.

"If you add a child to that, that doesn't decrease the amount of issues," he said. "It actually increases them. … You see [these teenage mothers] later and you see that their ability to adapt to this is very difficult. They're young single moms, usually living with their parents."

Noting a further connection between obesity and teen pregnancy, Garreton noted that many girls who become pregnant as teens already have a weight problem.

"They had a poor diet to start with and they continue through their pregnancy," he said. "By the time they deliver, they have the same problem, and it's hard to control their diet. They're not in control of their lives to start with."

L.A. County's public health department reported in 2008 that about 30 percent of the children in L.A. City Council District 9 – the city's southside – were obese.