ABC News' Rebecca Jarvis opens up on infertility and surrogacy journey to becoming a family of 4

Rebecca Jarvis is ABC News' chief business, technology and economics correspondent. Earlier this month, she and her husband Matt Hanson welcomed a son, Leo, who was born via surrogate. The couple are also the parents of a 4-year-old daughter, Isabel.

Jarvis opens up in her own words about her decade-long struggle with infertility and her journey to becoming a mom for a second time with the help of a surrogate.

It has been a very long road for us, for fertility, for pregnancy. And through the journey, I've come to see how common it is and how many families are facing these challenges - the emotional and the physical toll, the costs involved, the sadness and heartbreak and the hope, too.

I started trying to get pregnant with Isabel almost 10 years ago, and we were in and out of doctors' offices all over the city, constantly on calls, constantly going to appointments.

We did in-vitro fertilization to get pregnant with Isabel.

Before her, I had done seven rounds of IVF.

I think one of the hardest parts of our fertility journey is that it's always been unexplained.

We've looked into the eyes of so many doctors and said, "Please, just tell us anything you can tell us."

We've done every test under the sun, and there's never been a conclusive reason. I know now, having gone through this, that that's the case for so many women.

Every time I got pregnant, I would look at the world with rose-colored glasses, and I would imagine what life was going to be like on the other side. And every time I lost a pregnancy, to have that taken away was so tough.

I will also say, as a mom to Isabel, it was very tough for me because I wanted to be a great mom to her too. I didn't want that pain that I felt to take away from the joy that I felt with her.

Two years ago, in hopes of having a second child, Jarvis suffered a miscarriage after undergoing another round of IVF.

I had just lost a pregnancy at five months. We looked at our doctors and said, "What do we do? This keeps happening, and there's no telling whether we can be successful, whether I can maintain a successful pregnancy."

And our doctors said, "Surrogacy is your best path forward."

That was hard to hear in a way, at the time.

One of the things that we found when we started the surrogacy journey is that it can take a very, very long time to match with a surrogate, given the number of families who are now trying to conceive and are pursuing this option.

And one of the things that we really talked a lot about beforehand was whether or not we could even ask another person to do something like that with their body. It was really through the process of talking to a lot of people, and then getting to know our angel, our surrogate, and understanding that she considered this one of the greatest things she could do, one of the greatest gifts that she could give the world.

Even in the surrogacy, I really did hold my breath for a very long time. I -- probably in some ways to protect myself and my family -- didn't want to feel that massive excitement and that massive joy until I really felt that it was truly a sure thing.

But when I did allow myself to feel that way, it was truly the best feeling. To be able to look at Matt and say, "We are having a baby. We're having another baby. Isabel is going to have a little brother. Our family will be a family of four."

It was truly magical.

In November, Jarvis and Hanson flew from New York City to be at their surrogate's side when she gave birth to their son Leo.

When we left New York to witness the birth, I couldn't get over how surreal the whole thing was. That, and just feeling so happy, but also how strange it was that we were going to get on an airplane, fly across the country, and, God willing, come home with a baby boy.

To have it be real now is the best.

The moment Isabel met Leo, to see her meet her little brother and to give him such care and such sweet kisses and hugs, she really is an incredible big sister.

Also, the feeling of gratitude toward our surrogate and her family -- I just wanted to hug her and give her all of our love that we were also pouring over Leo, because there's no way this would've been possible without her.