Rubella Virus Infections During Pregnancy,Toronto, 1963-66

Among 670 pregnant women who attended the antenatal clinics of two Toronto city hospitals and one suburban hospital between May 1963 and January 1966, 29 of 550 patients apparently acquired rubella neutralizing antibodies, including 12 whose initial sera were collected during the first trimester. None developed overt rubella. Although rubella antibodies were detected in 61 to 79% of mothers aged 20 years or more, and antibody conversions were detected in 4 to 10% of mothers in each five-year age group between 16 and 39 years, tho rubella syndrome did not appear among any of their offspring. Five of seven other infants, aged 4 to 22 weeks, with the rubella syndrome excreted rubella virus. Rubella neutralizing antibodies were detected in all seven of these infants; these persisted at least 56 weeks in one subject. One mother who received gamma globulin during the first trimester was delivered of an infant who showed signs of the rubella syndrome.     

Clinical and Serological Assessment of Children Exposed in Utero to Confirmed Maternal Rubella

As a result of the work of the Public Health Laboratory Service Working Party on Rubella (1970) it was possible to examine the children of 60 susceptible women who were in contact with rubella during their pregnancy and who subsequently showed serological evidence of the infection, despite immunoglobulin prophylaxis. When the children were assessed between 8 months and 4 years 8 months of age a blood sample was also taken and tested for rubella antibodies so that a retrospective diagnosis of congenital rubella infection could be made. Only 19% of children exposed to subclinical maternal rubella showed evidence of intrauterine infection compared with 53% of those born to mothers who had clinical rubella. One of the 26 children exposed to subclinical maternal infection had a rubella defect, compared with 9 of the 34 children exposed to clinical maternal rubella.     

Rubella Vaccination and Termination of Pregnancy

Six terminations of pregnancy have been carried out in Leicestershire since February 1970 because of rubella vaccine administered inadvertently during early unrecognized pregnancy. Any woman of child bearing age shown by serological tests to be susceptible to rubella should be offered vaccination, preceded and followed by adequate contraception.     

Studies on Rubella in Pregnancy: Report of the Public Health Laboratory Service Working Party on Rubella

In a further survey of women of child-bearing age neutralizing antibody to rubella virus was found in 80 to 96% of those sampled from different parts of the country.When assessment was restricted to susceptible pregnant contacts and rubella in the index case was confirmed by virus isolation immunoglobulin in the dosage used did not appear to give any appreciable protection.One instance of a confirmed second attack after known exposure to rubella among more than 100 immune contacts is recorded.The implications of all these findings are discussed.