Author(s): WITOLD MALINOWSKI, KATARZYNA SZCZERBA
In the last three decades, all over the world we have been observing a distinct increase in the number of twin pregnancies. The causes of this phenomenon can be found not only in the wider and more effective application of artificial procreation methods. At present, one of the most important natural factors responsible for the increase of this percentage is the raise in the age of women starting motherhood. This influence seems to have an impact in two aspects; at first – with age there is an increase in the frequency of idiopathic multiple pregnancies; second – there is a natural decrease in fertility related to the ageing of ovaries, and also the presence of disorders reducing women’s fertility, such as e.g. sexually-transmitted infections, uterine myoma or endometriosis, what in turn increases the necessity to apply techniques of supported reproduction and consequently an increase in the percentage of iatrogenic multiple pregnancies.