I too used decompression in 1968, for the recommended time and through the first stage of  labour.

I have been looking for a) any sort of survey on the ‘children’ and b) feeling very strongly that more research should be done for painless labour.

My experience was probably very like your mother’s, except that late in labour the 10lb baby proved to be a breach which may have been related to the decompression throughout labour, and resulted in late diagnosis.