The term multiple births indicates more than one fetus that are conceived in a single pregnancy. Depending on the number of offspring, there are different names for the multiple births. Generally, common multiples are two or three which are known as twins or triplets. During last two decades, there has been a phenomenal increase in the number of twins and multiple births.
There are several factors responsible for twins and multiple births. Some of them are heredity, race, number of prior pregnancies, delayed childbirths and infertility treatment. There are two types of twins such as monozygotic (identical) and dizygotic (fraternal). The identical twins have same chromosomes and identical physical characteristics. Fraternal twins are developed from two different eggs that are fertilized by two separate sperms. They may be different in sex. Twins birth is the most common type of multiple births. It occurs in about 1 out of 80 pregnancies.
Supertwins is referred to the triplets and other multiple births including quadruplets, quintuplets, sextuplets etc. However, higher order births are very rare. The proportion of triples is 1 in 7,000 to 8,000 births. The quintuplets are likely to born once in 47 million births.
Twins and multiple births involve some risks for the health of mother as well as babies. Pre-term or early labor is the most commonly seen risk which may lead to premature births. Twin or multiple pregnancies may last between 35 to 37 weeks instead of normal 40 weeks. The premature babies can have several health challenges. In addition to that, other medical conditions including gestational diabetes, preeclampsia, placental problems and fetal growth problems are likely to occur. Cerebral palsy, low birth weight and developmental delays are commonly found in twins. There is higher risk of developing many health problems with higher order multiple births. There may be higher mortality rate for the multiples. Hence, the twins or multiples are placed in Neonatal Intensive Care Unit (NICU) immediately after birth.