A Cincinnati mother gave birth to twin sons earlier this week, each weighing around 10 pounds, FOX 19 reported.

Tamara Kankowski delivered the twins, Lucas and Dillon, by Caesarean section at Bethesda North Hospital in Cincinnati.

Lucas weighed 10 pounds, 2 ounces, and Dillon weighed 9 pounds, 9 ounces — far higher than the average weight of 6-and-a-half pounds to 7 pounds for a twin baby at birth, said Dr. Manny Alvarez, senior managing editor of FoxNewsHealth.com, who specializes in high-risk pregnancies. In addition to outweighing his twin brother, Lucas also beat him out by one minute.

The twins fell just short of setting the world record for the combined weight of newborn twins, set a few years ago in Britain at 23 pounds and 12 ounces. But the twins are the largest to have been delivered at the hospital.

“This is extremely rare and just by definition – even for a single baby as far as weight – 10 pounds would still be classified large for gestational age and considered above the 90th percentile,” Alvarez told FoxNews.com.

And while it’s not known if Kankowski suffered from gestational diabetes, which is a type of diabetes that occurs only during pregnancy, Alvarez said it could be a possibility.

“Many times the increased amount of weight on babies could be due to excessive exposure to glucose (sugar), which can cause the baby to grow very large. Other possible reasons are just the fact that some babies are just born that way due to a family history of large babies,” he added.

Lucas and Dillon are Kankowski’s sixth and seventh children.

"I have big babies anyway, but we thought with twins we would actually have little babies," Kankowski said. "But we were at about 36 weeks when we found out they were going to be bigger than that, and we realized we were going to have toddlers again."

Tests are being run to determine if they are identical twins.

"They seem to look more and more alike each time we look at them," said Kankowski.

“I’ve delivered 8-pound twins in my practice – but 10-pound twins – that’s almost unheard of,” Alvarez said.

Click here to read more from FOX 19.