Pregnancy: Woman conceives twice within five days in rare phenomenon

The mum gave birth to two children on the same day, but they are technically not twins.

A woman in California reportedly got pregnant while already pregnant, giving birth to two children on the same day. However, the kids are technically not twins because they were conceived five days apart in an extremely rare medical phenomenon.


Odalis Martinez, 25, gave birth to six-month old girls, Lilo and Imelda on minutes apart on August 10, 2021. Prior to this, Martinez, based in San Pablo, California, had suffered a miscarriage and so was very anxious when she went in for her first ultrasound. She told Kennedy News Media:

The doctor comes in and I'm trying to mentally prepare myself for anything and when she found the first baby and the heartbeat I was crying with so much happiness. I felt like the first baby that we had lost was in the room with me and saying it was going to be OK.

The infants are products of a rare medical phenomenon known as superfetation. This is when a foetus forms while another is already present in the uterus. In this case, the first foetus had been in there five days before the second joined egg was fertilized by a second sperm.

This phenomenon is so rare, it has been documented less than 10 times throughout human history. Some experts are even sceptical it exists at all.

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Technically not twins

Although born on the same day, the kids are technically not twins because they were conceived on different days. But according to Martinez, the two do look alike, so much so that their dad, Antonio, 31, often confuses them.

Martinez however says, because she’s with them most of the time, she can tell them apart. And because they were conceived in a rather unique way, Martinez finds it easier telling people they’re twins.

…after reading a lot of articles I know that they’re technically not twins. But it’s just confusing for people so I just tell them like ‘Yeah, they’re twins.’
This woman’s ‘pregnancy’ turned out to be something much worse This woman’s ‘pregnancy’ turned out to be something much worse