Abstract
Author(s): WITOLD MALINOWSKI, KATARZYNA SZCZERBA
A clear increase in incidence of multiple pregnancies has been observed since the beginning of 1970s. Reasons for that phenomenon should be sought not only in increasingly broad and effective use of artificial procreation methods, but also in changes of the natural environment of humans. At present the following are recognised as the most important natural factors of increasing incidence of multiple pregnancies: twin pregnancy in the past or in members of close family (presence of the, so called, “twin gene” responsible for polyovulation), great body height and/or significant increase of mother’s body weight, consumption of large volumes of dairy products and sweet potatoes, breastfeeding, oral contraception, black race, folic acid supplementation, high coffee consumption