Prenatal ultrasonography and the diagnosis of fetal cleft lip

Objective. To determine the efficacy of obstetric ultrasonography in the de tection of fetal cleft lip. Methods. The study population included all wome n who had a fetal anatomic survey with adequate visualization of the face a nd who gave birth at Brigham and Women's Hospital between January 1, 1990, and January 31, 2000. All neonates born with cleft lip were identified from the Brigham and Women's Active Malformation Surveillance Program. Confirma tion of the anatomic defect was obtained from the pediatric record or from the pathologic report if the pregnancy was terminated or ended in miscarria ge. Cases of isolated cleft palate were excluded. An ultrasonography databa se was used to identify all cases of cleft lip diagnosed before delivery. M aternal information regarding the pregnancy was abstracted from the medical record. Statistical significance was determined using the chi (2) statisti c for categorical variables and the t test for continuous variables. Result s. A total of 56 confirmed cases of cleft lip were identified in the study population. Overall, 73% of the cases (41 of 56) were identified antenatall y. Additional fetal anomalies were present in 54% of the cases (30 of 56). A comparison between those cases that were detected and those in which the diagnosis was missed showed that there was a significantly lower detection rate if the ultrasonography was performed before 20 weeks (12 [57%] of 21 v ersus 29 [83%] of 35; P = .035). There was no difference between the 2 grou ps in terms of maternal age or weight. Maternal parity prior maternal abdom inal surgery the presence of a multiple gestation, or coexisting fetal anom alies did not significantly affect the detection rate. There was no differe nce in detection rate in the first half of the study period (1990-1995; 23 [72%] of 32) compared with the second half (1996-2000; 18 [76%] of 24; P = .79). Conclusions. In this cohort of women, the rate of detection of fetal cleft lip was significantly lower when the anatomic survey was performed be fore 20 weeks' gestation. This difference could not be accounted for by suc h variables as prior maternal abdominal surgery, coexisting fetal anomalies , or improvements in ultrasonographic detection with time. We recommend tha t the anatomic survey for fetuses at high risk for this condition be perfor med after 20 weeks' gestation.