P05.19: Constriction and complete occlusion of the ductus arteriosus associated with maternal use of acetaminophen

Abstract

Objectives: 1) To establish normograms (using predicted interval formulas) of fetal pulmonary artery diameters and ratios as a function of fetal biometric parameters (FBP). Study design: Cross sectional study: Fetuses with the following criteria following fetal echocardiography were recruited for this study: 1) known gestational age based on LMP or early ultrasound, 2) unremarkable fetal echocardiogram study, 3) full fetal biometry, 4) singleton gestation, and 5) no major anomalies. Data of the following pulmonary artery (PA) parameters were taken if measured in each fetus at least three times: 1) Main PA (MPA) diameter, 2) Right branch PA diameter, 3) Left branch PA diameter and 4) Ascending Aorta. The following ratios were calculated: MPA/RPA, RPA/LPA, MPA/LPA and MPA/AO. Pearson coefficients (P) were calculated for each parameter versus the following FBP: 1) Biparietal diameter, 2) Head circumference, 3) Abdominal circumference (AC), 4) Femur length (FL), 5) Estimated fetal weight and 6) Calculated fetal gestational age (CFGA) based on biparietal diameter and femur length. Predicted interval normograms (95%tile confidence intervals) were developed using SPSS for fetal pulmonary artery diameters and ratios. Results: One hundred and fifty-five fetuses have been enrolled in this study. Gestational age range was 124–272 days. PA diameters were well correlated to all the FPB (all P > 0.85), suggesting a stable linear relationship. Arterial diameter ratios were stable across the gestational age range studied and appeared independent of FPB. Conclusions: Normograms (based on Predicted Intervals, 95% CI) for fetal PA diameters and ratios are established for a variety of FBP. In the absence of known gestational age, these normograms of fetal pulmonary artery diameters can be used reliably as a basis of comparison.