Rare Double Pregnancy: California Mom Has 'Superfetation' Where She Conceives Two Babies but Not Twins

California mom Odalis Martinez was pregnant with her youngest child when she conceived another baby in a matter of days. Her pregnancy is known as superfetation or a rare double pregnancy that occurs when the sperm fertilizes another egg after an initial pregnancy.

The mom explained her case in a simple way. She said that she got pregnant with her daughter while already pregnant with her youngest child, another girl.

However, the mom and her husband, Antonio Martinez, know that their babies are technically not twins, but they tell everyone they are "twins" to avoid confusing people.

Pregnant While Already Pregnant - How Does it Go?

The case of being "pregnant while already pregnant" has intrigued experts for years, but the actual number of superfetation cases is unknown. In 2008, less than 10 cases of this rare double pregnancy have been recorded globally. Most of the documented cases are also implantations via in vitro fertilization after the first conception has commenced.

In England, mom Rebecca Roberts was also told that her pregnancy is a superfetation, and it was the first such case for her obstetrician of 25 years. Dr. David Walker explained that Roberts' body didn't stop ovulating after she conceived her baby, so another egg was released, which was fertilized after three weeks.

After 33 weeks, Roberts gave birth to Noah and Rosalie via C-section. Rosalie was smaller than her brother, but both babies today are healthy. They share a unique sibling bond like no other.

In the case of the Martinez parents, Odalis' doctor was able to pinpoint the time of the second baby's conception via ultrasound. The test also confirmed that the second baby is not a twin of the first baby.

Initially, Odalis was concerned about her visit to the doctor because she and Antonio suffered a baby loss four months earlier. She was nervous and anticipating that her doctor would say they could not hear a heartbeat since it took her some time to explain what they found out from the ultrasound.

"[The doctor] started going back and forth and I was wondering why," Odalia said as she prepared for the worst-case scenario, per Daily Mirror. "That's when she told me that she had found another baby that also had a heartbeat."

Odalia and Antonio are overjoyed for this rare double pregnancy.

Welcoming Lilio and Imelda

In August 2021, Odalia and Antonio welcomed two healthy daughters, Lilio and Imelda. They were born at 40 weeks, the perfect pregnancy term. Lilio weighed 6lbs 12oz, while Imelda weighed 7lbs 3oz.

The mom said that her rare double pregnancy is truly a special miracle. She didn't have any problems or complications at all. Though Lilio and Imelda aren't twins, her parents said they sometimes have problems telling each other apart because they look so much alike.