I'm the biological mom of 3 sets of twins, but 2 sets were born to other moms 15 years after conception.

• Marie Johnson produced 15 embryos via IVF. Two resulted in twins and she donated the rest.
• Two more sets of twins were born to other parents 15 years after the embryos were frozen.

This as-told-to essay is based on a conversation with Marie Johnson. It has been edited for length and clarity.

We had a large family reunion in fall 2019. The kids played in the game room of the lodge we'd rented, laughing and joking around the pool table and pinball machine.

It was especially touching to watch my twins, Kurt and Alex, looking out for the two other sets of twins who shared their looks and DNA.

It felt phenomenal to know that though I was the biological mother of all six children, four of the twins were born to other couples. They resulted from my husband, Randy, and I donating our leftover embryos from in vitro fertilization to four would-be parents.

We desperately wanted to have children of our own

Randy and I struggled to have a baby for three years before we began fertility treatment around 2001. I had polycystic ovary syndrome, which messed up my menstrual cycle. The condition was almost certainly the reason we hadn't been able to conceive.

We started with the least invasive treatments, such as Clomid and a total of 10 rounds of intrauterine insemination. Nothing worked. We tried to keep our spirits up. But when we got those negative test results, it was such a downer. We desperately wanted to have children of our own.

At first, we ruled out IVF. It was mostly the expense and that I was almost 37. But we met a fertility doctor at the Mayo Clinic who specialized in women with polycystic ovary syndrome. We were lucky enough to create 15 embryos in October 2002 on our first attempt.

Our 12 leftover embryos were frozen and stored for future use at a clinic

We had a fresh transfer of three embryos and two of them implanted. I gave birth to our fraternal twins in June 2003. They were gifts from God.

We froze the remaining embryos because we would have loved to have had more kids. But Randy had recently been diagnosed with multiple sclerosis. It later turned out to be neurosarcoidosis, which can mimic the symptoms of MS. We thought, "It might not be the right thing to do to try to have more."

Still, we kept our 12 leftover embryos frozen for about $500 a year. We wanted them to at least have a chance of life. I knew a younger woman would be more likely to have a healthy birth.

In 2008, we donated the embryos to the National Embryo Donation Center, a religious organization that matches recipients with donors. We have a strong Christian faith, and the cryopreservation was free. I was told that not many donors did this, but we ticked the box for an "open adoption." It meant we could have a relationship with the recipients and our biological offspring. We wanted those children to know that we loved them and would like to know them.

There were a couple of inquiries from people who considered adopting the embryos. But they didn't go beyond the paperwork. I got a little discouraged as the years went by.

Then in 2016, Jeni and Danny Gardner came forward. They lived in Charleston, South Carolina, more than 1,300 miles from our home near Minneapolis-St. Paul. I thought, "This is our family." I was impressed that they wanted to adopt despite having five children already.

They got pregnant. We talked throughout the pregnancy and became close. Randy and I were delighted when Jeni gave birth to Matthias and James in November 2017. They were fraternal twins, just like Alex and Kurt. Our teenage sons thought it was very cool to have two little brothers.

It felt like a miracle when Amy and Robert Hefner of Memphis, Tennessee, chose to adopt our remaining embryos. The transfer took place a few days after the Gardner boys arrived.

2 sets of my biological twins share a birthday. They were born exactly 15 years apart.

One of the embryos resulted in pregnancy. Then, to everyone's surprise, it divided in half. Amy gave birth to their identical girls, Aliza and Eliana, prematurely at 32 weeks. Thankfully, they were healthy. Incredibly, the last set of twins was born in June 2018 — 15 years to the day after Alex and Kurt were born. They share the birthday.

Jeni, Amy, and I called and texted each other from the get-go. They were Christians, and we had a lot else in common. It made sense that the kids should meet their siblings.

We flew to Charleston to see the Hefners in August 2018. Aliza and Eliana were 3 months old. Our boys held them in their arms. Then we drove to Memphis to meet the Gardners. We were very emotional when we hugged Matthias and James. The six siblings had blue eyes and, funnily enough, similar-looking ears to Randy's. The tips of their ears fold down a bit. It was cute.

All three families met up in 2019 when we stayed in the lodge near Nashville, Tennessee. Things felt so real. Randy and I posed for photos with our six biological children. Everyone got on well — especially the twins and the older Gardner kids. We had the best time. We have a special bond. Jeni and Robert had their biological son, Colin, in 2020. The twins are now 19, 5, and 4. Together, we're a family of 20.

We're grateful for each other.

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