Michelle Duggar, star of the TLC show "18 Kids and Counting," gave birth to her 19th child Thursday, according to a statement from TLC, which airs the program.

Josie Brooklyn arrived three months prematurely and weighed only 1 pound, 6 ounces. She was due March 18, according to the Duggar Family Web site.

Slideshow: The Duggar Family

Duggar, 42, was hospitalized last weekend for gallstones, and she was given an emergency Caesarean section Thursday evening.

"Michelle is resting comfortably, and baby is stable and in the NICU for extended care," read a statement on TLC's Web site. "The most important thing right now is for Mom and baby Josie to get as much rest as possible. The family is grateful for all the prayers and well wishes during their recovery."

Dr. Manny Alvarez, chairman of the Department of Obstetrics and Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey, told FoxNews.com that a baby of Josie's size could face many challenges.

"Some of these challenges could include cerebral palsy, deafness, blindness, chronic respiratory problems, chronic gastrointestinal problems and bleeding in the brain," said Alvarez, who is also managing health editor of FoxNews.com. "Everything really depends on the first 30 days of life."

Alvarez said Josie would most likely stay in the neonatal intensive-care unit for up to four months.

Babies typically can leave the NICU when they are able to breathe without support, maintain a stable body temperature, breast or bottle-feed and gain weight steadily.

Duggar, and her husband, Jim Bob, now have 19 kids whose names all begin with the letter "J."

The Duggars' eldest son, Josh, and his wife, Anna, recently gave birth to a baby girl too.

Click here to read more at Michelle Duggars' blog.