Additional data on spontaneous abortion and facial cleft malformations.

Examination of fetal wastage data for a large collection of CL +/- P and CP sibships reported previously (Bear 1978) does not indicate the frequency of recognized abortion to be higher in the sibships of CL + P vs CL index cases, female vs male CL +/- P index cases, bilateral vs unilateral CL +/- P index cases, female bilateral CL +/- P index cases vs male unilateral CL +/- P index cases, or male vs female CP index cases. These observations fail to confirm those reported by Dronamraju (Dronamraju et al. 1982, Dronamraju & Bixler 1983a, b), and provide no evidence of a positive relation between degree of liability to facial cleft malformation and fetal mortality.