Brooke Mueller Went To Rehab Twice For Crystal Meth WHILE PREGNANT With Charlie Sheen's Twins

Two of Brooke Mueller's multiple rehab stints occurred while she was pregnant with twins Bob and Max and married to Charlie Sheen, RadarOnline.com has learned exclusively.

The startling information that Mueller used drugs while pregnant comes in the wake of her temporarily losing custody of the twins to Charlie's ex-wife, Denise Richards. What's more, RadarOnline.com has learned from several sources that Brooke has been to rehab 20 times over the years.

During Mueller's pregnancy with Sheen's twins, "she went to rehab twice because she was using drugs," a source told RadarOnline.com about the tragic situation. "Brooke's two rehab stints consisted of less than 30 days.

"It just shows how far gone Brooke is with her battle of using crystal meth. The fact that she couldn't stay sober while carrying Bob and Max caused Charlie great anguish."

Mueller recently checked into the Betty Ford Clinic for a 30-day treatment stint, marking the 20th time she’s entered a treatment facility to seek help for substance abuse.

As RadarOnline.com first revealed last week, Mueller and Sheen’s twins were taken away from her because of fears their mother’s drug use could endanger them. Richards was given temporary guardianship of the boys, with Sheen’s approval.

That followed Mueller being placed on an involuntary psychiatric hold at the UCLA Medical Center.

Meanwhile, the Los Angeles County of Department of Children & Family Services "has been made aware of Brooke's rehab stints while pregnant. It's truly amazing that she was able to hold onto custody of the boys for as long as she did. Brooke's road to getting custody back of the boys is going to be very, very long," the insider revealed.