Validation of radiographic criteria for the diagnosis of Down syndrome in stillborn infants

3137 fetuses in 33 years: What we have learned from the Wisconsin stillbirth service program

The Wisconsin Stillbirth Service Program (WiSSP) provided expert review by a dysmorphologist for community-acquired data on 3137 fetal deaths between 1983 and 2017. Intrinsic fetal causes were consistently identified in about 25% while placental and maternal causes were recognized with increasing frequency as attention was shifted from a primarily fetal to a multifocal approach. Identification of causes increased from 40% to 78% and in about half of cases results of the review altered recurrence risk and/or future pregnancy management. Banked data from WiSSP formed the basis of 24 publications, more than half of which have a genetic counselor and/or summer premedical student intern as an author. The earlier publications emphasized validation of the concept of community-based evaluation with central review, the utility of various parts of the WiSSP protocol, the similarity of second-trimester miscarriages <20 weeks to later stillbirths with respect to causes identified and recurrence risks, and the potential for results of etiologic evaluation to influence future prenatal care. The most important recurrent theme, however, was the interaction of intrinsic fetal, placental, and maternal factors in contributing to fetal demise. This implies that, at least in developed nations with available obstetric care, reduction in stillbirth will require careful attention to the myriad of factors contributing to fetal, placental, and maternal well-being.

Radiographic evaluation of stillbirth: what does it contribute?

Despite advances in perinatal care, stillbirth is relatively common (1/160 births) and frequently remains unexplained. Most recent protocols for etiologic evaluation of stillbirth either omit radiography or reserve it for infants with obvious skeletal disproportion. Over the past 30 years, the Wisconsin Stillbirth Service Program has collected radiographic images from 2,032 stillbirths and second trimester losses, of which about 25% (517) showed abnormalities. Review of these images by a medical geneticist showed that radiographs yielded a diagnosis in 45% of the infants with abnormalities (11.5% of all radiographs obtained) and were critical, yielding a diagnosis that would otherwise have been missed or incomplete in 1.5% of the total infants. The probability of a diagnosis was not significantly different between miscarriages <20 weeks and stillbirths. Diagnoses were mainly fetal, most commonly sporadic birth defects, idiopathic hydrops, chromosome abnormalities, and skeletal dysplasias, but chorioamnionitis with fetal sepsis, complications of twinning, and cord accidents were also diagnosed radiographically. Radiographs may help direct the use of newer technologies such as chromosomal microarray or gene sequencing. Limiting radiographs to infants with obvious skeletal disproportion would have resulted in many of these diagnoses, including 4/24 skeletal dysplasias, being overlooked. We recommend at least an anterior/posterior babygram film as part of the permanent record of all second trimester losses and stillbirths.

Array-based comparative genomic hybridization (aCGH) in the genetic evaluation of stillbirth

This study examined the utility of array-based comparative genomic hybridization (aCGH) in detecting genetic abnormalities associated with late pregnancy loss. Comparisons were made with classic cytogenetics to test whether aCGH represents a superior methodology for the clinical evaluation of stillbirth. Stillborn infants were selected for aCGH testing from the Wisconsin Stillbirth Service Program (WiSSP) database and tissue bank, based on abnormal clinical findings (presence of at least two abnormalities of two different organs or parts of the body). aCGH analysis was successfully completed in 15 cases which met the clinical criteria and for which sufficient amount of high quality DNA was recovered from archival material. The testing was performed using commercially available 1 Mb BAC arrays. Among 15 tested stillborns, aCGH detected two abnormalities (trisomy 21 and an unbalanced translocation between chromosomes 3 and 10), for an overall detection rate of 13% in stillborns with malformations who had normal or unobtainable cytogenetic results. This preliminary study supports the clinical value of aCGH testing in diagnostic evaluation of stillborns with congenital anomalies.