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/ Source: TODAY
By Rheana Murray

Weeks after welcoming her first child to the world, actress Gabrielle Union is opening up about the health condition she believes caused her fertility problems for so long.

After several miscarriages — so many that Union has said she lost track, although she guesses around eight or nine — Union learned she has adenomyosis.

"We just decided as a family that the best and safest and probably our most successful route was a gestational carrier, so a gestational carrier is your surrogate," she said in a video shared recently on her Instagram page.

Union and her husband, Dwayne Wade, welcomed their "miracle" baby last month, via surrogate.

What is adenomyosis?

Adenomyosis is a thickening of the uterus, or, as Union describes it on social media, "endometriosis of the muscle." It occurs when endometrial tissues move into the walls of the uterus.

"Many people are familiar with endometriosis but not adenomyosis," Dr. Ryan Martin, a fertility specialist for Shady Grove Fertility in Warrington, Pennsylvania, told TODAY Health. "It's similar in the fact that it's endometrial tissue in the wrong place. In this instance, it's endometrial tissue in the walls where the muscle is. That causes the uterus to be bigger and not function the way it normally would."

The uterine abnormalities caused by adenomyosis can lead to fertility problems.

"It doesn't eliminate the chance of getting pregnant, it just makes it harder," Martin said. "It makes the uterus less receptive to accepting an embryo to grow in pregnancy. You can take perfectly normal embryos and put them in a uterus that has abnormalities and have a much lower success rate as a result."

"The problem with adenomyosis is that we can't fix it," he added. "There's no way to just take out the adenomyosis. The only real treatment is a hysterectomy, so obviously if you're trying to get pregnant, that's a devastating thing to talk about."

What are the symptoms of adenomyosis?

The main symptom of this condition is painful periods, and it may affect up to 65 percent of women, according to the Cleveland Clinic.

"It's not all that unusual," Martin said. "Most of the time, one does not need a gestational carrier, but in some situations, that could be a viable option."

Continuous birth control pills can help lessen the pain by stopping a woman's monthly menses.

"You don't have to have periods to be healthy," Martin said. "You can sort of hit the pause button on the growth, but being on birth control pills wouldn't help you get pregnant."

In an interview with Oprah, Union said she learned she had adenomyosis only after "seeing the world's leading IVF doctors for a number of years."

The star has been vocal about her journey to parenthood on social media, often speaking up about the "guilt and shame" women unfairly face when it comes to not being able to give birth.

"Every path to motherhood looks different," she said in a recent video. "There's no one right way."