Hi Julia and welcome to the board.
I had a baby 10 years after diagnosis (dx age 25), at the age of 36. I am so happy - 0% regrets

. My son has brought me & my husband so much joy. I did have a relapse about 6 months after I gave birth but it wasn't any more severe than normal, and I suspect my very low Vitamin D3 levels may have contributed to that. My MS story is complex enough and I don't want to go into the whole speil here but I'd have a few suggestions for you if you decide to go ahead:
1) try to put aside as much money you can into an account. Only use this if there's an MS-crisis. We saved enough for a one-year fulltime creche place for our son, and help in the home, and a years' worth of mortgage payments, should I get bad.
2) get your vitamin D3 levels checked now and get them into an optimal range before you get pregnant. Jimmylegs on this board is brilliant on this info! Get them checked again immediately after birth and supplement if necessary. Also research the issue of D3 supplementation in newborns - discuss with your GP see the info here:http://www.fsai.ie/assets/0/86/204/bd98b833-f7ec-48df-8989-0c60619bb552.pdf - this will reduce your risk of passing MS on to your little one.
3) Accept help. If people offer to help with a newborn, take them up on the offer. Each time you can rest, especially when you're dealing with sleeplessness, will help you get through. If you're going through a period of bad fatigue, hire a cleaner for 2 hours a week. If you don't feel up to shopping, get the shopping online. When your baby sleeps, you sleep too and ignore the mess. Things like this really help.
Regarding the fairness of knowingly bringing a little one into the world given our possible limitations, and the risk of transmission - I'd just say this. I think if you are a resourceful person who accepts help, who's open to finding solutions for the problems that MS throws at you, and who is determined, then I think it is fair. Other poeple have no idea what life will throw at them in the future either. You can be a great Mother and have a disability.
Hope that helps and best of luck in your decision.
I have never been so happy in all my life as now. I love being a Mum!