Lung Growth and Intrapulmonary Circulation in Fetuses With Anhydramnios Due to Severe Renal Anomalies Treated With Serial Amnioinfusions.

OBJECTIVE

To evaluate changes in fetal lung size/volume and intrapulmonary circulation after serial amnioinfusions (AMI) in fetuses with early anhydramnios.

METHODS

Ten fetuses with anhydramnios due to renal agenesis (n = 4) or renal dysplasia (n = 6) were treated with serial AMIs. Before AMI, the following ultrasound parameters were obtained: fetal lung area, total lung volume (TLV), O/E LHR, thorax circumference (TC), cardiothoracic ratio (CTR), and pulsatility index of the main intrapulmonary artery (IPA). Differences in lung biometrics between the first and last AMIs are reported.

RESULTS

One hundred thirty-nine (median n = 14, [7-22] per patient) AMIs were performed. All deliveries were at ≥ 29 + 6 weeks/days of gestation. There were increases in lung areas (Left (z-scores (z-sc)) -1.86/-0.35; p < 0.001, Right -2.09/-0.81; p = 0.002), and in O/E LHRs (Left 0.56/0.73; p = 0.04, Right 0.57/0.73; p = 0.009). TLV increased (z-sc 0.24/0.53; p = 0.7) and IPA decreased (z-sc 0.87/0.43; p = 0.051), but differences were not significant. No differences in TC (z-sc 0.57/0.56; p = 0.97) or CTR (0.58/0.58; p = 0.1) were documented. The distribution of all lung biometric parameters across pregnancy showed values below the expected mean for gestational age.

CONCLUSIONS

Fetuses with early anhydramnios treated with serial amnioinfusions showed an increase in lung size; however, this increment was below the expected mean for gestational age.