Prenatal findings in 11 cases with craniofacial microsomia using the Alberta Congenital Anomalies Surveillance System, 1997-2019.

Craniofacial microsomia (CFM) primarily includes specific head and neck anomalies that co-occur more frequently than expected. The anomalies are usually asymmetric and affect craniofacial features; however, there are frequently additional anomalies of variable severity. Published prenatal findings for CFM are limited. This study contributes 11 cases with CFM and their anomalies identified prenatally. Cases born between January 1, 1997 and December 31, 2019 with CFM were abstracted from the Alberta Congenital Anomalies Surveillance System, which is a population-based program ascertaining congenital anomalies for livebirths, stillbirths, and termination of pregnancies for fetal anomalies. There were 11 cases ascertained with prenatal findings including facial anomalies: one each with left cleft lip, right microtia, and bilateral microphthalmia. Two cases had vertebral anomalies. In addition, anomalies of the kidneys, brain, heart, and radial ray were identified. Six (55%) had a single umbilical artery, five (45%) were small for gestational age, and three (27%) were from a twin pregnancy that were discordant for anomalies. Four (36%) overlapped another proposed recurrent constellations of embryonic malformation condition. This study describes prenatal findings for 11 cases with CFM. Comparable to prior published cases, there were recurring anomalies on prenatal imaging, including anomalies of the brain, eye, heart, kidneys, and radial ray, which may aid in the prenatal diagnosis of CFM.

Craniofacial Microsomia, Associated Congenital Anomalies, and Risk Factors in 63 Cases from the Alberta Congenital Anomalies Surveillance System.

OBJECTIVE: To report associated congenital anomalies with unexplained craniofacial microsomia (CFM) and the phenotypic overlap with other recurrent constellations of embryonic malformations (RCEM), and to assess prenatal and perinatal risk factors. STUDY DESIGN: This is a retrospective cross-sectional study. Cases with CFM, delivered between January 1, 1997, and December 31, 2019, were abstracted from the population-based Alberta Congenital Anomalies Surveillance System. Livebirths, stillbirths, and early fetal losses were reviewed to include all types of pregnancy outcomes along the spectrum of this condition. Prenatal and perinatal risk factors were compared with the Alberta birth population to assess differences between the 2 groups. RESULTS: There were 63 cases with CFM, yielding a frequency of 1 per 16 949. There was a high rate of cases (65%) with anomalies outside the craniofacial and vertebral regions. Congenital heart defects were the most common (33.3%). A single umbilical artery was found in 12.7% of cases. The twin/triplet rate of 12.7% was significantly higher than the Alberta rate of 3.3% (P < .0001). There was an overlap with a second RCEM condition in 9.5% of cases. CONCLUSIONS: Although CFM is primarily a craniofacial condition, the majority of cases have congenital anomalies affecting other systems requiring additional assessments, including an echocardiogram, renal ultrasound examination, and a complete vertebral radiograph. The high rate of an associated single umbilical artery raises the possibility of a related etiological mechanism. Our findings support the proposed concept of RCEM conditions.

Recurrent constellations of embryonic malformations re-conceptualized as an overlapping group of disorders with shared pathogenesis.

Several recurrent malformation associations affecting the development of the embryo have been described in which a genetic etiology has not been found, including LBWC, MURCS, OAVS, OEIS, POC, VACTERL, referred to here as "recurrent constellations of embryonic malformations" (RCEM). All are characterized by an excess of reported monozygotic discordant twins and lack of familial recurrence. We performed a comprehensive review of published twin data across all six phenotypes to allow a more robust assessment of the association with twinning and potential embryologic timing of a disruptive event. We recorded the type of twinning, any overlapping features of another RCEM, maternal characteristics, and the use of ART. Statistically significant associations included an excess of monozygotic twins and 80% discordance rate for the phenotype across all twins. There was an 18.5% rate of ART and no consistently reported maternal adverse events during pregnancy. We found 24 instances of co-occurrence of two RCEM, suggesting a shared pathogenesis across all RCEM phenotypes. We hypothesize the following timing for RCEM phenotypes from the earliest perturbation in development to the latest: LBWC, POC, OEIS, VACTERL, OAVS, then MURCS. The RCEM group of conditions should be considered a spectrum that could be studied as a group.