|Summary of non-randomized interventional human trials for cleft recurrence*|
|Study||Intervention||Supplemented group||Control group||Reduction|
|# births||RR (%)||# births||RR (%)|
|Conway (1958)||MV and 0.5mg FA||59||0.0||78||6.4||100% (p=0.1)|
|Peer et al. (1964)||MV and 5mg FA and 10mg B6||176||2.2||418||4.7||53% (p=0.1)|
|Briggs 1976 [extension of Peer et al. (1964)]||MV and 5mg FA and 10mg B6||228||3.1||417||4.8||35% (p=0.2)|
|Tolarova (1982)||MV and 10mg FA||84||1.2||206||7.3||84% (p=0.02)|
|Tolarova and Harris (1995)||MV and 10mg FA||211||1.4||1824||4.2||66% (p=0.03)|
MV=multivitamin; FA=Folic acid; RR=Recurrence Rate.
* Conway , Peer et al.  and Briggs  included mothers to children with cleft lip and/or cleft palate. Tolarova  included mothers to children with cleft lip with/without cleft palate (CL/P). Tolarova and Harris  included women with CL/P or mothers to a child with CL/P.
** The total recurrence for treated and control groups is based on total number of affected births divided by total group size (or proportion of each study’s recurrence relative to its sample size). Peer et al.  and Tolarova  are excluded as these data were included in other studies.
Wehby et al.
Wehby et al. BMC Pediatrics 2012 12:184 doi:10.1186/1471-2431-12-184