Question

you may have read that sometimes a women may deliver more than two offsprings at a time collect more information from Internet about reason for such incidences.

Answer 1

A multiple birth is the culmination of one multiple pregnancy, wherein the mother delivers two or more offspring. A term most applicable to placentalspecies, multiple births occur in most kinds of mammals, with varying frequencies. Such births are often named according to the number of offspring, as in twins and triplets. In non-humans, the whole group may also be referred to as a litter, and multiple births may be more common than single births. Multiple births in humans are the exception, and can be exceptionally rare in the largest mammals.
Twins=2
Triplets=3
Quadruplets=4
Quintuplets=5
Sextuplets=6

The frequency of N multiple births from natural pregnancies has been given as approximately 1:89N-1 (Hellin's law) and as about 1:80N-1.[17] This gives:

1:89 (= 1.1%) or 1:80 (= 1.25%) for twins1:892 (= 1:7921, about 0.013%) or 1:802 (= 1:6400) for triplets1:893 (= approx. 0.000142%, less than 1:700,000) or 1:803 for quadruplets

North American dizygotic twinning occurs about once in 83 conceptions, and triplets about once in 8000 conceptions. US figures for 2010 were:[18][19]

Twins, 132,562, 3.31%Triplets, 5,503, 0.14%Quadruplets, 313, 0.0078%Quintuplets and more, 37, 0.00092%

Human multiple births can occur either naturally (the woman ovulates multiple eggs or the fertilized egg splits into two) or as the result of infertility treatments such as IVF (several embryos are often transferred to compensate for lower quality) or fertility drugs (which can cause multiple eggs to mature in one ovulatory cycle).

For reasons that are not yet known, the older a woman is, the more likely she is to have a multiple birth naturally. It is theorized that this is due to the higher level of follicle-stimulating hormone that older women sometimes have as their ovaries respond more slowly to FSH stimulation.[20]

Answer 2

Multiple births are seen in many different kinds of mammals. It occurs when when a single embryo splits into two or more embryos. The genetic materials of the offsprings is the same.

The name of the process is given depending on the number of offsprings delivered. The Pregnancy could also be as a result of fertilization of many eggs  that form many fetuses.