Parental HLA sharing, feto-maternal compatibility and neonatal birthweight in families with a history of recurrent spontaneous abortion.

The mean birthweight of babies eventually born to couples with a history of recurrent spontaneous abortion (RSA) is allegedly lower if the parents have a high degree of HLA antigen sharing (Reznikoff-Etievant et al., 1991), but this relationship has not been independently confirmed. We have re-investigated this question by analysing data from 36 families. In 22 instances, we were able to relate birthweight directly to feto-maternal HLA compatibility for the first time in such families. We were unable to confirm any appreciable influence of paternal or feto-maternal HLA sharing on birthweight or placental weight and conclude that RSA families do not differ markedly from normal families in this respect.