12 weeks after Allison Mathias fell pregnant she was told she was expecting triplets. A routine ultrasound found a fourth baby; she was having quads.
The chance of giving birth to quadruplets, naturally, in 1 in 800,000. The odds of those quads being identical are then one in eleven million. Unlike fraternal multiples who do not necessarily look alike and can even be a mix of sexes, identical quadruplets can only come from the same egg.
