Less common are triplets from a dizygotic pregnancy, where one zygote divides into two identical fetuses, and the other does not. Least common are identical triplets, three fetuses from one egg. In this case, the original zygote divides into two and then one of those two zygotes divides again but the other does not. Triplets are far less common than twins, according to the U.S. Centers for Disease Control and Prevention, accounting for only about 4300 sets in 3.9 million births, just a little more than 0.1%, or 1 in 1000. According to the American Society of Reproductive Medicine, only about 10% of these are identical triplets: about 1 in ten thousand. Nevertheless, only 4 sets of identical triplets were reported in the U.S. during 2015, about one in a million. According to Victor Khouzami, Chairman of Obstetrics at Greater Baltimore Medical Center, "No one really knows the incidence".Identical triplets or quadruplets are very rare and result when the original fertilized egg splits and then one of the resultant cells splits again (for triplets) or, even more rarely, a further split occurs (for quadruplets). The odds of having identical triplets is unclear. News articles and other non-scientific organizations give odds from one in 60,000 to one in 200 million pregnancies. Quadruplets
Quadruplets are much rarer than twins or triplets. As of 2007, there were approximately 3,556 sets recorded worldwide. Quadruplet births are becoming increasingly common due to fertility treatments. There are around 70 sets of all-identical quadruplets worldwide.
Neonatal intensive care
Multiple-birth infants are usually admitted to neonatal intensive care immediately after being born. The records for all the triplet pregnancies managed and delivered from 1992 to 1996 were looked over to see what the neonatal statistics were. Kaufman found from reviewing these files that during a five-year period, 55 triplet pregnancies, which is 165 babies, were delivered. Of the 165 babies 149 were admitted to neonatal intensive care after the delivery. Society and culture
Insurance coverage
United States
A study by the U.S. Agency for Healthcare Research and Quality found that, in 2011, pregnant women covered by private insurance in the United States were older and more likely to have multiple gestation than women covered by Medicaid. Cultural aspects
Certain cultures consider multiple births a portent of either good or evil.Mayan culture saw twins as a blessing, and was fascinated by the idea of two bodies looking alike. The Mayans used to believe that twins were one soul that had fragmented.In Ancient Rome, the legend of the twin brothers who founded the city (Romulus and Remus) made the birth of twin boys a blessing, while twin girls were seen as an unlucky burden, since both would have to be provided with an expensive dowry at about the same time. In Greek mythology, fraternal twins Castor and Polydeuces, and Heracles and Iphicles, are sons of two different fathers. One of the twins (Polydeuces, Heracles) is the illegitimate son of the god Zeus; his brother is the son of their mothers mortal husband.