Kate Elazegui, 41, and her wife Emily Kehe, 38, from New York, were told there was a "slim chance" they would both get pregnant when going through fertility treatment.
But despite the odds being against it the two women welcomed sons Eddie and Reid in December 2015.
"Sure, two babies is a lot," Elazegui told New York Magazine. "But we have four boobs, two mums, we have the same leave and we both know we can help each other.
"I have my best friend doing it with me."
Elazegui explained she was trying IVF to get pregnant with their first child when their doctor, Joo Kang, suggested Kehe try the insemination process.
Elazegui had previously spent six months trying inseminations and saw IVF as her "last resort".
Kehe fell pregnant after the first round and Elazegui found out she was expecting only three weeks later.
"We didn't know how fertile Emily was," said Elazegui. "She is the poster girl for womanhood. Her body was like, boom!"
Kehe said it was overwhelming when they found out they were both expecting and the couple, who married in 2013, both started panicking about the size of their flat and how their lives were about to change.
But after moving to New Jersey and buying a house, the panic eased off.
Elazegui suffered from gestational diabetes and said she didn't "enjoy" being pregnant, unlike Kehe.
Kehe told The Baby Centre: "The hardest part of it was really the differences between our pregnancies and trying to not compare.
"When it got difficult we didn’t complain about it too much. We just said, 'OK, can you do this?' and you just support the other through it."
Kehe's waters broke on 9 December, when she was 10 days past her due date. Her son Reid was born after just nine pushes.
Elazegui said she thinks it was the feeling of being in a "hyperdrive" after watching Kehe's labour that kickstarted her own labour, just three days later.
Unlike her wife, Elazegui spent two and a half hours pushing before her son, Eddie, was born.
Kehe said while it was hard leaving Reid, she knew she had to be there for Elazegui when she was giving birth.
Now, the couple are at home with their newborns. They explained how their "maternal instinct" is to take care of the baby they gave birth to, so it is a bit of a challenge to bond with them both.
The couple are both on maternity leave until March and said they will be looking for a nanny, because they both have to go back to work full-time.
Elazegui added: "We've been married only two years, but I think this has made us closer faster and more intimately than couples married far longer."