According to Hellin's law chances of twins in pregnancy are :

Ans. is c i.e. 1 in 80 According to Hellin's rule The mathematical frequency of multiple pregnancy is : Twins 1 in 80 Triplets 1 in (80)2 Quadruplets 1 in (80)3 and so on Also know 7 The incidence of twins is highest in Nigeria (1 in 20).deg It is lowest in far East countries.deg Incidence in India - 1 in 80.deg Incidence of twins is increasing in India because of the use of ovulation inducing drugs like clomiphene, gonadotrophins.deg The incidence of monozygotic twins is constant throughout the world - 1 in 250. The incidence of dizygotic twins changes and is responsible for world wide variation in incidence. The incidence of Dizygotic twins increases with : - Increasing maternal age - Increasing parity - Family history of twinning - Ovulation induction with clomiphene citrate or gonadotrophins.