Erin Credo is rarely speechless. But the 33-year-old from Baton Rouge, Louisiana, had no words on March 24. That’s the day she learned she was expecting her second set of identical twins.
“I took a picture of the ultrasound and sent it to my husband,” Erin told TODAY Parents.
Jake Credo was home with their 6-year-old sons, Cooper and Grant.
“He was confused. He wrote back, ‘Is that the boys?’” Erin recalled. “And I was like, ‘Oh no. That is not our boys. That is this pregnancy.”
Dr. Cliff Moore, the maternal fetal medicine physician who oversaw Erin’s pregnancy, was just as shocked.
“Only about 1 in 111,111 pregnancies results in a second set of identical twins,” Moore told TODAY Parents. “To put that in perspective, we deliver approximately 8,000 babies at Woman’s Hospital each year, so we’d only see that about once every 15 years.”
The pregnancy itself came as a big surprise. Erin and Jake struggled for more more than two years to conceive Cooper and Grant.
We were kind of on the fence about having more because I didn’t want to go through that again,” Erin revealed. “I never in my life thought I’d have four kids. I’m still in disbelief.”
Identical twins, also known as monozygotic twins, account for .4% of all pregnancies, according to Dr. Dave Colombo, division chief of maternal fetal medicine at Spectrum Health in Michigan.
“The chance of having identical twins is pretty consistent across the world. The only thing that seems to increase the risk of having identical twins is using assisted reproductive technologies,” Colombo told TODAY Parents. “The rate of non-identical twins is affected by a mother’s age, race, family and how recently she used birth control.”
Erin’s pregnancy wasn’t without complications — the family contacted COVID-19 in August — but on Sept. 22, the Credos welcomed their second set of identical twins: Lola and Allie.
The girls, who were born at 32 weeks and 3 days gestation, stayed in the hospital for four weeks to gain weight, and came home on Tuesday morning. Each wears a different color nail polish so that Erin and Jake can tell them apart.