Measurement of fetal atrioventricular intervals in pregnant women with anti-SSA/Ro antibodies.

Purpose: The objective of our study was to compare and consider reference values of fetal atrioventricular (AV) intervals as measured by four different pulsed Doppler wave techniques (left ventricular inflow/outflow [LV in/out], pulmonary vein/pulmonary artery [PV/PA], innominate vein/ascending aorta [InnV/AA], and supra vena cava/ascending aorta [SVC/AA]) in pregnant women with anti-SSA/Ro antibodies.

Methods: Between March 2014 and September 2020, 52 pregnant women with anti-SSA antibodies were enrolled. No bradyarrhythmia was observed in the group. A pulsed Doppler examination of the fetal heart was performed to obtain measurements of the mechanical Doppler AV interval. Doppler measurements were performed using four methods: LV in/out, PV/PA, InnV/AA, and SVC/AA. A statistical analysis was performed to examine the mean, standard deviation, significant difference, and correlation of the four methods. The detection rate of each method was also calculated.

Results: There was no significant difference in the AV intervals between any of the four methods. There was also a positive correlation in the AV intervals of each of the four methods. The fetal heart rate and AV interval showed no correlation. The gestational age and AV interval also showed no correlation. The detection rate was highest for LV in/out (62.6%, 95% confidence interval: 56.5-68.4).

Conclusion: All four pulsed Doppler methods are useful for measuring AV intervals. The most practical method is LV in/out.