Very interesting question indeed !

The human reproductive system is naturally designed to produce ONE offspring per fertilisation . This is because the EGG made available , to be fertilised by the males spermatozoon is always ONE per ovulation cycle ! However , some aberrations , driven by naturally occurring hormones or food substances could cause the shedding of multiple eggs per cycle , resulting into multiple births of twins , tripplets , quadruplets etc . The babies resulting from this phenomenon are always UNIDENTICAL because they possess different genetic materials from different ovums and spermatozoon.

Identical multiples occurs when a single OVUM ,after fertilization by a spermatozoon, splits equally and each member developes into separate foetus , which grows to become identical babies !!

While the above scenarios are naturally induced , artificial stimulation of multiple births could be achieved by several biological interventions like ingesting of fertility hormones or test tube technology where extracted ovas can be fertilised invitro in a laboratory and the resultant foetuses implanted into the womb !!

I wish you good luck in your quest to have twins ; even quadruplets 🤣