Lucy Liu has announced the delivery of a baby boy with the help of a surrogate mother.

The 46-year-old actress made the announcement through Instagram, where she posted a photo of herself holding her son, Fox News reports.

A representative said she had a gestational carrier for her son. Other celebrity couples have also used surrogates to carry their children, including Jimmy Fallon and his wife Nancy, Sarah Jessica Parker and husband Matthew Broderick, and actress Nicole Kidman and husband Keith Urban.

A gestational carrier (or surrogate) is a woman who carries a child for another couple, but is not the biological mother of the child, according to the American Society for Reproductive Medicine.

Typically an egg from the biological mother and sperm from the father are combined through in-vitro fertilization, then the fertilized embryo is implanted in the gestational carrier.

Tomer Singer, M.D., a reproductive endocrinologist at Lenox Hill Hospital in New York City, estimates that about 5 percent of the couples he sees with fertility problems use a gestational carrier.

Older women are likely than younger women to need a gestational carrier, because some the risk of some conditions that affect the ability to carry a pregnancy — such as uterine fibroids, and recurrent miscarriages — increase with age,