Kristen Wiig Calls IVF the 'Most Difficult Time in My Life' Before Twins' Birth via Surrogate

The road to motherhood was anything but a straight line for Kristen Wiig.

In the September issue of InStyle, the actress opens up about the physical and emotional hoops she and fiancé Avi Rothman had to jump through before eventually welcoming now-9-month-old twins via surrogate, calling the experience "a very long road" on which "I wasn't myself" for years.

"We've been together for about five years, and three of them were spent in an [in vitro fertilization] haze," says Wiig, 46. "Emotionally, spiritually and medically, it was probably the most difficult time in my life. I wasn't myself."

"There are so many emotions that go with it — you're always waiting by the phone and getting test results, and it was just bad news after bad news," adds the Wonder Woman 1984 star. "Occasionally there would be a good month, but then it was just more bad news. There was a lot of stress and heartache."

"It was a long f---ing time," she continues. "It got to the point where I just kind of stopped talking about it entirely, because I would get sad whenever someone asked. It was just part of my life. I gave myself [hormone] shots in airplane bathrooms and at restaurants — and those shots are no joke."

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Wiig says it was "hard not to personalize" her experiences when she got a "negative result," recalling, "You go through so much self-deprecation, and you feel like your partner may be seeing you in a different way and all this other stuff we make up in our heads."

"But when I did talk about it, every time I said that I was going through IVF, I would meet someone who was either going through it, about to go through it or had a friend who just did it," adds the Saturday Night Live alum. "It's like this underground community that's talked about but not talked about."

At first, Wiig wasn't open to having another woman carry her child. "I remember when our doctor mentioned going other routes and I was just like, 'Nope. Don't ever bring that up again. I'm getting pregnant. I'm doing this,' " she says. "I finally realized that I just needed help. And, thank God, we found the most amazing surrogate."

And during the pregnancy, it was still difficult — but she found the silver lining by understanding that the end result was exactly what she had been searching for.

"So many things were bittersweet," Wiig says. "I was over the moon feeling them kick for the first time, but then I would get in my head and ask myself all these questions, like, 'Why couldn't I do this?' At the same time I would tell myself it didn't matter. She was giving us the greatest gift, and I just wanted them to get here!"

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Once they came around to the idea of surrogacy after the initial reservations, Wiig and Rothman, a filmmaker, "tried to keep the process private for as long as possible, because it is a very private thing."

"As private as I am and as sacred as this all is, what helped me was reading about other women who went through it and talking to those who have gone through IVF and fertility stuff," the Bridesmaids actress tells InStyle. "It can be the most isolating experience. But I'm trying to find that space where I can keep my privacy and also be there for someone else who may be going through it."

And even though she wishes she "had talked about it more and asked for more help," as there is "such a support system out there" for hopeful parents going through similar experiences, she notes that "overall it was a very beautiful thing" to welcome her children via surrogacy.

"Now that I'm on the other side, I wouldn't have had it any other way," Wiig says. "I've always believed that things happen the way they're supposed to happen, and this is how [our babies] were supposed to get here. I became really close with our surrogate, and it was her first time doing it so we kind of went through everything together. When the children were born, I wanted to make sure she was okay and she wanted to make sure I was okay."

"It was a lot of navigating through emotions and respecting that she had a connection with them and trying to be really honest about how I was feeling. Ultimately, I realized that I'm very fortunate," she adds. "I'm grateful. I'm a different person now."