Hi,
Welcome back to ehealthforum,
Thanks for the repeat query,
If your wife has had a previous abortion, then there are chances that she has had uterine adhesions or scarring (as a result of previous abortion) that is not letting her to have a pregnancy. Other possibilities could include ovarian suppression or ovarian failure if she has used any medications at time of abortion. If the ultrasound report shows that uterus dimensions are fine, then the other causes should be ruled out by getting a Hysteroscopy and HSG (hysterosalpingogram test) done which will show if there are any problems inside uterus or any tubal block that is causing infertility. Discuss about these possibilities with her treating gynecologist or take a second opinion from another gynecologist. Hope this helps.
Take care.