omg I just wrote a long reply and then closed my browser window by mistake.
The condensed version is that the Foundation's brochure "Pregnancy and RLS" is near teh bottom of the page
https://www.rls.org/member-portal/publications under "information for healthcare providers" and requires a membership to read. Membership fees go to fund research into RLS/WED (including better treatments) and to educate doctors and nurses about the disease.
The brochure does not recommend or say to avoid any particular medication during pregnancy. Like polar bear, I thought that the dopamine agonists like mirapex were not generally used during pregnancy, that the safest option is suboxone (similar to methadone), even though the baby has to be weaned off it after birth. The brochure does say to not use medication unless treatment with iron and lifestyle changes have failed, and even then to use the lowest dose possible. A google search for "mirapex pregnancy" turns up things like this one from the FDA: "There are no studies of pramipexole in human pregnancy. Because animal reproduction studies are not always predictive of human response, pramipexole should be used during pregnancy only if the potential benefit outweighs the potential risk to the fetus." From emedTV "In animal studies on Mirapex (pramipexole) and pregnancy, the medication impaired implantation and increased the risk of early miscarriages when it was given to pregnant rats. However, the drug has not been studied in pregnant humans". From an abstract on PubMed (
https://www.ncbi.nlm.nih.gov/pubmed/23083216), on a positive note, records were examined of 59 women exposed to parmipexole (Mirapex), ropinirole, levodopa, or rotigotine during pregnancy, and found no more spontaneous abortions or malformations than in the general population (I don't know how many of the 59 were on pramipexole, nor how long the exposure, what dose, etc).
The best advise in the brochure is to get your serum ferritin checked, if you haven't lately; oral iron during pregnancy is apparently ok to take, and might have a dramatic impact on your symptoms if your ferritin is low right now. The recommendation in the brochure is to get it up above 75 ng/ml, but some specialists think 100 is a better goal. The brochure says IV iron might be considered if ferritin is very low (below 30) and oral iron hasn't been effective.
The lifestyle changes they suggest include: avoid triggers (alcohol, caffeine which stays in pregnant women longer, Benadryl, etc), do moderate exercise, eat well, avoid sleep deprivation(!!), and get up as soon as symptoms start because if you stay in bed they will get worse and last longer.
They also gave 3 websites that supposedly give info about safety and risks of various meds during pregnancy and lactation, and I carefully copied them here, but I also searched each one briefly and found nothing relevant - a deeper search may have, I suppose.
They refer to a paper that details the risks of various WED/RLS meds for pregnant and lactating women, and luckily I did copy down the reference for that one (see below*), but I cannot access the actual paper because my online library access seems to be misbehaving.
I would get that brochure and read it, find out as much as you can elsewhere, and see your doctor and talk about it some more, give him/her the brochure. Ask about your ferritin and supplementing with iron. Iron is a biggie, and it would be cool if you could control it with that alone. the thing you have to be aware of with mirapex is that you may be augmenting, the lower your ferritin the more likely you will augment, and the higher your dose the worse you will feel - - with a lag during which you feel better, so you think it's working. It might also be useful to print one of the Foundation's brochures on augmentation for your doctor?
Best of luck with this! (I don't think I managed to condense it!)
*Picchietti DL, Hensley JG, Bainbridge JL, Lee KA, Manconi M, McGregor JA, et al. Consensus Clinical Practice Guidelines for the Diagnosis and Treatment of Restless Legs Syndrome/Willis-Ekbom Disease During Pregnancy and Lactation. Sleep Med Rev 2015; 22:64-77. Review.