# Association of neonatal and fetal malformations with polyhydramnios and oligohydramnios - introduction of a new “association factor”

## TL;DR

This study explores how abnormal amniotic fluid levels during pregnancy are linked to specific fetal and neonatal malformations.

## Contribution

The paper introduces a new statistical 'association factor' to quantify the link between amniotic fluid abnormalities and fetal malformations.

## Key findings

- Amniotic fluid abnormalities were most common in urogenital and abdominal anomalies.
- Polyhydramnios showed strong associations with craniospinal and abdominal wall disorders.
- Oligohydramnios was highly associated with urogenital system malformations.

## Abstract

Our aim was to investigate the association of different neonatal and fetal anatomical abnormalities with polyhydramnios or oligohydramnios during prenatal ultrasonography.

In our study, we processed prenatal sonographic and postnatal neonatal clinical and pathological data from 2,622 fetuses with malformations over a 12-year period. We investigated the association of neonatal and fetal abnormalities with polyhydramnios or oligohydramnios. To characterize the prevalence of association between a given disorder and polyhydramnios or oligohydramnios, we used our proprietary “association factor” (AF) for statistical calculations.

Amniotic fluid volume abnormalities were most frequently detected in urogenital, abdominal, and abdominal wall anomalies. In urogenital anomalies, amniotic fluid volume abnormalities were found in more than half of the fetuses, 54.86% (oligohydramnios 34.72%, polyhydramnios 20.14%). In abdominal and abdominal wall anomalies, 43.82% of fetuses had abnormalities in the volume of amniotic fluid (polyhydramnios 31.44%, oligohydramnios 12.38%). Overall, we found abnormalities in the volume of amniotic fluid in over 30% of the fetuses with craniospinal, thoracic and pulmonary anomalies, limb anomalies, and ossification disorders. In craniofacial and cardiovascular anomalies, amniotic fluid volume abnormalities were only detectable in around 20%. For polyhydramnios, the “Association Factor” (AF) was very high for craniospinal, abdominal, and abdominal wall disorders, and it was high for cardiovascular, urogenital, limb, and ossification disorders. For oligohydramnios, the association factor (AF) was very high for urogenital disorders.

If the amniotic fluid volume during ultrasonography is less or more than average, special attention should be paid to the ultrasound examination of the fetus’ urogenital system, abdominal organs, skull, spine, chest, lungs, as well as limbs and skeletal system. In the case of polyhydramnios, fetal echocardiography is recommended.