It means the fertilisation of two ova

SUPERFECUNDATION :
● It means the fertilisation of two ova which have been discharged from the ovary at the
same period ,by two separate acts of coitus committed at short intervals.
● The incidence of twin pregnancies is about one-and half percent, and of these about
70% are binovular twins resulting from separate fertilisation of two" ova formed in the
same menstrual cycle.
● Development of twins in utero is parallel but not equal, depending on the relative blood
supplies from the separately formed placentae.
● Both ova do not always develop to maturity. One foetus may be aborted early or die and
retained until the labour that expels the other.
● The dead foetus may be flattened by pressure and may not be recognisable, and is
referred to as foetus compressus or foetus papyraceus.
● The spermatozoa causing fertilisation may be from different men. The rare cases
wherein two ova are fertilised by a white and black person or persons with entirely
different blood groups are the only certain examples of this condition