[Risk of the recurrence of cleft lip and palate after changing of partner or residence].

The aim of the present study was to determine the effect of changing residence on recurrence of congenital facial cleft defects. We identified 4189 women that had given birth to infants with a facial cleft detect by linking a database comprising facial cleft cases born between 1952 and 1987 with the Central Person Registry in Denmark. Changing municipality did not decrease the frequency of recurrence of facial cleft defects in later-born sibs. Among the 907 infants of mothers who changed municipality but not partner, 29 (3.2 percent) had a facial cleft defect, as compared with 48 (3.4 percent) of 1425 infants of mothers who changed neither municipality nor partner. However, change of partner significantly reduced the recurrence risk. Among 236 infants of mothers who changed partners, 1 (0.4 percent) had a facial cleft defect, as compared with 77 (3.3 percent) of 2350 infants of mothers who did not change partners. Recurrence of facial cleft defects is not linked to the residence of the mother, but having a different partner reduced the woman's risk of having a second infant with this defect.