Published online by Cambridge University Press: 15 May 2009
1. The A.S.O. titre of cord blood is about 1½ times that in the mother's blood taken 4 weeks before delivery.
2. The distribution of A.S.O. levels in cord bloods from multiparae with children at school is not significantly different from that in multiparae whose children are under school age, or in primiparae.
3. Among these groups, only primiparae show a significantly increased A.S.O. level in winter.
4. The distribution of A.S.O. levels among the five social classes defined by the Registrar-General's occupation code showed a significant trend towards higher levels in the lower social grades.
We wish to thank Mr D. M. W. Maxwell, F.R.C.S., F.R.C.O.G. and Miss D. Slade, S.R.N., S.C.M. at Taplow, and Professor J. C. McC. Browne, F.R.C.S., F.R.C.O.G., Dr W. Hayes, D.Sc., F.R.C.P.I. and Miss M. Tweedle, S.R.N., S.C.M. at Hammersmith Hospital for their kind help.