Jenna Jameson has been breastfeeding her daughter for 18 months — how does 'full-term breastfeeding' work?

Jenna Jameson regularly shares photos on Instagram of herself nursing her daughter, Batel. And in a new post, she revealed that she’s been breastfeeding her daughter for 18 months.

“18 months nursing this little angel,” she captioned a shot of Batel snuggled up against her. “I can’t describe the incredible bond full term breastfeeding creates. It’s hard work, time consuming and sometimes frustrating… but I wouldn’t change one second.”

Several moms chimed in, commenting with their own stories of nursing their children for 18 months or longer. But… what is full-term breastfeeding, exactly?

Also known as “extended breastfeeding,” it’s a term used to describe breastfeeding until your child decides to wean themselves, Leigh Anne O’Connor, a board-certified lactation consultant and La Leche League leader, tells Yahoo Lifestyle.

“The definition of weaning is to be satisfied. Babies do not naturally wean before the age of 2 years,” she says. “Terms like ‘full-term nursing’ and ‘extended nursing’ have come about because as a culture, we wean prematurely.”

The American Academy of Pediatrics recommends that mothers exclusively breastfeed their babies for the first six months, if they’re able, and that they continue nursing (while feeding their child solid foods) up to a year or longer if the mom and baby wish. (Mothers who aren’t able to breastfeed or prefer not to can instead turn to formula-feeding, which is a perfectly safe option).

The World Health Organization also recommends exclusively breastfeeding for up to six months, with continued breastfeeding along with foods until the child is age 2 or older.

“There is no upper limit” to how long mothers should continue to nurse, “but a mom decides what is best for her and her child,” says lactation consultant Joan Younger Meek, MD, RD, chairwoman of the American Academy of Pediatrics section on breastfeeding and associate dean for graduate medical education at Florida State University’s College of Medicine. “Any breastfeeding is better than none, and the longer the mother breastfeeds her child, the better it is for her own health and for her child’s,” she tells Yahoo Lifestyle.

There are definitely benefits to nursing a child beyond six months, O’Connor says. “Toddlers who nurse have a strong immune system, and their oral cavity and teeth are developed appropriately,” she tells Yahoo Lifestyle. “They typically eat a larger variety of foods.”

Breast milk can also help these toddlers when they’re sick, she says. “The milk hydrates them, and the milk picks up on the bacteria and creates antibodies to fight off infection,” O’Connor says.

“The benefits are similar to what happens with any breastfeeding,” says Joanne Goldbort, PhD, RN, a breastfeeding researcher and assistant professor at Michigan State University’s College of Nursing. “There are nutritional benefits, health benefits from the antibodies in the mother’s milk, and mother-baby attachment benefits.”

The U.S. is one of the few countries in the world where it’s not common to nurse beyond 12 months, Goldbort says. “In other countries, it’s not uncommon for children to be at the breast until 3 and 4 years of age,” she says.

Of course, breastfeeding isn’t easy or even possible for all moms, and shorter maternity leave compared to other areas in the world can make it difficult for moms to nurse as long as they’d like. But Meek recommends that mothers try to nurse through the first year if they can. “There is no downside to continued breastfeeding beyond 12 months of life,” she says. “There is no reason for a mother to wean from breast milk to start giving her child cow’s milk after 12 months.”

Meek encourages moms to “take it day-by-day and continue breastfeeding as long as possible, ideally for at least one year, and even better if she continues for at least two years.”

Read more from Yahoo Lifestyle:

• Nun scolds breastfeeding mom at doctor’s office: ‘That’s inappropriate — you can’t do that in here

• New mom hangs ‘no breastfeeding zone’ sign to alert nurses that she’s a breast cancer survivor

• Trump approves act that requires airports to have breastfeeding rooms

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