Benefits of a systematic approach in the evaluation of fetal facial 3-dimensional volumes

Assessment of Midfacial Hypoplasia in Down Syndrome Fetuses - Validity of a Two-Line Approach and Introduction of a Novel Angle (Maxilla-Mandible-Nasion Angle)

PURPOSE

To scrutinize the validity of a novel angle (maxilla-mandible-nasion angle, MMN) as objective proof of midfacial hypoplasia in trisomy 21 fetuses.

MATERIALS AND METHODS

Volume data sets of 2(nd) trimester fetuses were reviewed in this retrospective study. After achievement of the correct midsagittal position, the fetal profile line (FP line) and the mandibulo-maxillary line (MML) were applied and the resulting angle was calculated. Additionally, the prefrontal space ratio (PFSR) was assessed. Both measurements were obtained from 401 euploid fetuses and 42 fetuses with trisomy 21. Values for MMN and PFSR<5(th) percentile were considered abnormal.

RESULTS

The study included 443 fetuses with a mean gestational age of 21.3 weeks (range: 14.0-26.3). The MMN angle sufficiently identified hypoplasia of the midface in trisomy 21 fetuses (mean: 14.6°; range: 10.1°- 22.0°) compared to controls (mean: 20.5°; range: 17.3°-23.7°; p<0.0001). Concomitantly, the PFSR of Down syndrome fetuses was significantly lower (mean: 0.53; range: 0.21-1.22) than in euploid individuals (1.38; range: 0.54-2.23; p<0.0001).

CONCLUSION

Calculation of the novel MMN angle in 2(nd) trimester fetuses reliably allows rapid assessment of craniofacial anatomy in order to rule out the midfacial hypoplasia frequently found in trisomy 21.

Prenatal diagnosis of congenital syphilis using two- and three-dimensional ultrasonography: case report

The numbers of syphilis cases have been increasing considerably, especially in eastern europe, thereby contributing towards greater chances of cases of congenital syphilis. Some of the complications of congenital syphilis can be detected on two-dimensional ultrasonography (2DUS), and these are generally manifested in the second trimester of pregnancy. The commonest ultrasonographic signs are hepatosplenomegaly, placentomegaly, and fetal growth restriction, while lower-frequency occurrences include intrahepatic calcifications, ascites, fetal hydrops, and even fetal death. Three-dimensional ultrasonography (3DUS) is a relatively new imaging technique that is adjuvant to 2DUS and enables detailed assessment of the fetal surface anatomy. We present a case of a 21-year-old primigravida with a diagnosis of congenital syphilis, with obstetric 2DUS findings of hepatosplenomegaly, ascites, pericardial effusion and hyperechogenicity of the cerebral parenchyma. 3DUS in rendering mode allowed clear assessment of the fetal limbs, especially the feet, which appeared twisted and lacked some toes. It allowed the parents to understand the pathological condition better and improved prenatal management and neonatal followup. 3DUS can be used routinely for assessing fetal malformations resulting from congenital infections.