Interventricular Septal Thickness as a Diagnostic Marker of Fetal Macrosomia

Serious complications in both mother and newborn arising as a result of fetal macrosomia indicate the need for early diagnosis and prevention. Unfortunately, current predictors, such as fetal biometry, fundal height, and amniotic fluid index, appear to be insufficient. Therefore, we decided to assess the predictive potential of interventricular septal thickness (IVST), as measured at ≥33 weeks of gestation. Two hundred and ninety-nine patients met the inclusion criteria: complete medical history including all necessary measurements—namely, IVST obtained by M-mode echocardiography, fetal biometry, and birth weight. The Statistica 13.1 PL software was used to generate the receiver operating curve. The optimal cut-off point (IVST of 4.7 mm) was selected using the Youden index method. The analysis of fetal biometry abnormalities resulted in 46.6% of macrosomia cases being correctly predicted; however, IVST analysis detected 71.4% of cases. IVST at ≥4.7 mm appears to have a higher sensitivity and negative predictive value (NPV) than routine ultrasound.

RASopathies: A significant cause of polyhydramnios?

OBJECTIVE

The aim of the study is to determine the prevalence of RASopathies in a polyhydramnios cohort selected by postnatal medical genetics evaluation.

METHODS

In this retrospective study, we reviewed 622 pregnancies with polyhydramnios seen at Lucile Packard Children's Hospital between 2008 and 2017. The findings from 131 cases evaluated by Medical Genetics were included in our final analysis. Genetic testing information was extracted to determine the rate of chromosomal or single gene conditions focusing on the RASopathies. Additional variables collected were: maternal characteristics, ultrasound findings, and the severity and timing of diagnosis of polyhydramnios.

RESULTS

Postnatal genetic testing or clinical examination identified a genetic disorder in 63 (48.1%) cases, more than half (n = 33) of which had a single gene condition. Postnatal testing revealed an underlying RASopathy in 15 (11.5%) cases. An underlying RASopathy was significantly associated with the severity and timing of polyhydramnios (p < 0.05).

CONCLUSION

Focusing on a selected cohort postnatally evaluated by Medical Genetics, our study identified a chromosomal or genetic disorder in almost half of pregnancies complicated by polyhydramnios. Specifically, an underlying RASopathy was found in 11.5% of cases with 13/15 of these cases having additional ultrasound findings.