Although mumps vaccine virus has been shown to infect the placenta and foetus, there is no evidence that it causes congenital malformations in humans; and (3) Reports have indicated that contracting wild-type measles during pregnancy enhances foetal risk.
Ning (3) andmed on näidanud, et looduslikesse leetritesse haigestumine raseduse ajal suurendab lootekahjustuse riski.