Can the KY birth index be searched by bmoms name only?

I very recently made contact with my bio family. My bmom died a few years ago. Her sister and father told me that my bmom had another baby after me, also put up for adoption. I was born and adopted in St. Louis but they said this baby was born in Louisville KY and it would have been after me. I was born in Sept. 1968 so this other baby could not have been born before June 1969. Bmom's father said that bmom would take off and disappear for months or even sometimes years at a time and then she would just show up again. Because of that, they never knew if the baby was a boy or a girl or the exact birthdate or other pertinent info. So, all that I have to go on at this point is that I do know my bmoms name and her date of birth. I was born at Booth Hospital in St. Louis, so if there was a Booth Hospital in or around Louisville KY it would make sense that she would have delivered her second baby there as well since she'd already be familiar with it. I believe that we had different bio fathers, although I don't know who this second baby's bio father would have been. My birth and adoption were never a family secret in her family and she wasn't forced to give the babies up, so it's very unlikely she bothered to use a fake name. I have absolutely nothing to go on as you can see and from what I can tell from reading here, the birth index is my only slim hope.