My son was born sick from a virus he caught in utero. He's now 10 and has several disabilities.

• My son was born at 35 weeks after a routine ultrasound showed calcifications in his brain.
• I'd heard of cytomegalovirus when I donated blood, but I hadn't connected it to my baby's health.

When I was 35 weeks pregnant with my second baby, I left my computer on at work to go to what I thought was a routine ultrasound appointment.

As the doctor scanned my stomach with the ultrasound wand, her smile faded, and her eyebrows furrowed. She explained that my son was small, that there were calcifications in his brain, and that I should drive to the hospital and deliver him immediately.

Two hours later, my son was born via emergency C-section. He spent five weeks in the NICU, where I eventually learned that he would most likely never walk or talk.

Sometime during my pregnancy, I caught a virus called cytomegalovirus, or CMV. The virus hadn't caused me any problems, but because my son didn't have an immune system, he couldn't fight off the virus himself.

I'd heard of CMV when I donated blood

Guilt barely describes the emotions I managed during those early months. I thought I'd followed all the protocols. I didn't drink alcohol. I didn't eat sushi. I didn't own a cat.

The more I researched, the more I learned how few pregnant women are aware of this very common virus. But I can't say I hadn't ever heard of CMV before — those three letters had popped up a couple of years earlier when I was a routine blood donor.

Each quarter I diligently visited the blood bank that came around to my corporate campus. One afternoon, a technician looked at my blood-donor card and pointed out the three letters with a minus sign typed on the bottom right. "How wonderful!" he said. "Your blood can be donated to preemies!" It meant I'd never contracted CMV.

The Centers for Disease Control and Prevention indicates that over half of US adults will have been infected with CMV by the time they're 40. The virus can be passed from person to person through direct contact with bodily fluids such as saliva, blood, or breast milk. Contracting CMV after birth poses very few risks.

I was proud that my blood could help newborns — but looking back, I wish I'd understood that it also meant I should try to avoid CMV if I ever became pregnant. Eventually, my son was on the receiving end of those blood donations because of challenges that had been preventable.

I connected with other moms going through the same thing

I know women who had a similar experience. Social media makes it easy for us to connect around the world. We share our stories and our struggles as we try to do the best for our children.

Some mothers had babies who died in utero from CMV, and some had babies who died right after they were born. Some have children who have hearing loss or are deaf. Some have children with very mild challenges, and others, like me, have a child with several disabilities.

Today my son is 10. He's amazing and has overcome so many challenges. But every day we fight for accessibility and inclusion. We find the doctors and therapists who support him best instead of the ones who don't understand. We work hard to find ways he can enjoy the same things as my other two children. Our journey so far has been tiring, but my son has taught me so much. I learned how to advocate for him, but also how to advocate for myself.

Jaclyn Greenberg writes about her experiences parenting as well as challenges related to accessibility and inclusion. She's writing a memoir about the importance of advocating for her children and for herself.