Pregnancy is recognized as one of the factors that promote the development of poliomyelitis. Anderson (1948) quoted statistics according to which the incidence of polio in pregnant women was twice or three times the expectancy. Polio in the last trimester was more serious than in the first six months. Aycock (1946) related that pregnancy predisposes to acute polio, with a tendency for the disease to occur in the first trimester in women carrying a male and in the third trimester in those carrying a female fetus.
Evidence to the effect that the polio virus cannot break through the placental barrier was advanced from several sides (Huerny, 1942; Froevig, 1947; Stokes, 1948; Blechmann and Oliveau, 1948). It would seem that not much danger awaits the progeny from direct transmission of the virus during gestation. But Aycock (1941) suggested that infection can be initiated during pregnancy, as paralytic polio was observed in
KELEMEN G. Acute Poliomyelitis of the Mother, with Aural Lesions in the Premature Infant. AMA Arch Otolaryngol. 1955;62(6):602–610. doi:10.1001/archotol.1955.03830060034009