Multiples: From Twins to Octuplets and Everything In-Between!

I just read an interesting article by AC producer, Michelle L. Devon (Michy) entitled, Are Identical Twins Really Identical? I have always been fascinated with multiples, especially identical multiples, so I did some research and found some very interesting information.

Recently, geneticists in the United States discovered a set of twins unlike any other twins medical science has ever seen. They call them them 'semi-identical twins'. This type of twin is so rare that it is possible they may be unique.

It appears that two sperm cells must have fertilized a single egg and each twin has DNA from each of the two separate sperm cells. While this does happen occasionally, it's only in about one percent of all human conceptions. Then, in most cases, the embryo is not viable. For a 'semi-identical twin' to form, this fertilized embryo then must split to form twins. Then, after all this has happened and the babies are born, something has to occur to get the attention of the geneticists. In this case, what got their attention was that one of the babies was born a true hermaphrodite, having both testicular and ovarian tissue. The other twin is a normal male infant. Neither twin has other physical or mental developmental abnormalities and they are now healthy two year olds.

I've always been especially fascinated with triplets and have often wondered about identical triplets. Triplets are rare enough, with 'spontaneous' triplets appearing in only about 1 in 8100 births; but Identical triplets are extremely rare, occurring about once in every 500,000 births. Triplets born from fertility treatments are never identical because with fertility intervention, individual eggs are used for zygotes (a cell that is the result of fertilization). To produce Identical triplets a single zygote must split into three.

Quadruplets can be either three separate fraternal siblings (the most common), or two sets of identical twins. Very rarely, there can be three identical triplets and one fraternal sibling or four identical quadruplets. For these last two extremely rare examples to occur, it means that the original fertilized egg splits and then one of the resulting cells splits again producing the three identical triplets; or in the case of four identical quadruplets, a further split occurs.

The odds of having five Identical quintuplets is about 1 in 57 million. The Dionne quintuplets, born in Canada in 1934, were the first, and still the only, identical quintuplets known to survive infancy. Several of the Dionne quintruplets are no longer living.

The largest number of babies born (with all the infants surviving beyond the first year of life) are seven (septuplets). The first surviving set of septuplets were born in 1997. They were the result of fertility drugs. Two of the septuplets suffer from cerebral palsy, but the other five are in good health. There's been just one other set of septuplets born where all seven children have lived past infancy. This set was born in Saudi Arabia in 1998. (There may also be an unconfirmed and unidentified all-male set of septuplets born in 2002 in India. It is rumored that they are all alive and doing well).

Several sets of octuplets (eight) have been born in the world but there have been none where all eight infants have lived past a few weeks of age. The 'most surviving set' was born in Texas in 1998. One of the babies died at one week of age, but the seven remaining children have grown up without complications. An unusual thing about the octuplets is that one of the babies was born 12 days before the other seven babies were born. (It was one of the later-born baby's that died at one week old).

Here is one more unusual story with a little different twist. It's about a set of identical twin girls who were separated at birth. The mother, Petita Penaherrera, didn't know she had given birth to twin girls 15 years earlier. She thought she'd had only one child. At a chance meeting in a restaurant in Equator, Petita and her 15 year old daughter, Andrea, came face-to- face with another young girl who looked exactly like Andrea. Petita reports, "After seeing a girl in the restaurant who was exactly like mine I almost fainted."

Marielisa, Andrea's identical twin, was there with her 'parents' who turned out to be the doctor couple who performed the Cesarean delivery on Petita fifteen years earlier and withheld the news that she had delivered identical twin girls.

Immediately, while Petita was still sedated, the husband and wife doctors secretly stole one of the babies. For the past 15 years they have raised the girl as their own. The doctors' claim that Petita did know she had delivered twin girls, but only wanted to keep one baby, and told them they could have the other one. Petita claims the doctors are lying and that she had no idea that she had delivered twins.

A law suit is pending.