Asian Influenza in Pregnancy. Relationship to Fetal Anomalies

Influenza infections during pregnancy: association with congenital malformations and with subsequent neoplasms in children, and potential hazards of live virus vaccines.

“…In other reports which have described specific congenital abnormalities in women with a history of influenza during the first trimester (10,12,20,43,46), the incidence of CNS malformations was no greater than in control groups with no record of influenza. Pleydell (35), however, suggested that the incidence of CNS malformations in Northamptonshire could best be explained by an infectious disease, but the only evidence for the implication of influenza was one case of hydrocephaly in 10 first-trimester infections.…”

“…Those based on clinical diagnosis and morbidity must be considered doubtful since they, too, would not have included mild and subclinical cases. From serological evidence, the attack rates among the patients studied in Baltimore (20) and Iowa (43) were over 80%, and in Los Angeles, 60% (46). If similar rates occurred in Dublin and Finland, a considerable dilution in the incidence rates of the clinical influenza cases would be expected.…”

“…Walker and McKee (43) investigated the outcome of pregnancy retrospectively in Iowa after the 1957 epidemic. Women were interviewed shortly after giving birth to determine those who had experienced "influenza-like" symptoms, and a blood sample was taken from those that had.…”

Environmental mechanisms of orofacial clefts

“…Based on observations, he speculated that if an influenza‐induced syndrome of birth defects existed, cleft lip would be among the four major congenital abnormalities most likely observed. However, several studies have disagreed that influenza infection is teratogenic (A. Czeizel, Tusnady, Domany, & Borsy, 1967; Doll, Hill, & Sakula, 1960; Walker & Mc, 1959; Widelock, Csizmas, & Klein, 1963; Wilson & Stein, 1969). Notably, different groups have reached divergent conclusions from the 1957 Asian influenza pandemic.…”

Viral teratology.

“…Influenza Virus For many years, influenza virus has been regarded as a potential teratogenic agent for the human fetus. However, there are probably just as many publications showing correlation between the disease and congenital malformations (20, 32,36,85,109,110) as there are negative reports denying this effect (18,108). The reasons for these contradictory reports can be explained in part by the methods employed for collecting data.…”