Transumbilical placement of the vaginal probe in obese pregnant women

Abstract

Transabdominal ultrasonography in obese pregnant women is often unsatisfactory because of the poor transmission of ultrasound through a thickened abdominal wall. We report our experience with the placement of a transvaginal probe in the umbilicus to improve resolution in obese pregnant patients. The technique, which involves filling the umbilicus with ultrasound transmission gel and inserting the transvaginal probe into the umbilicus, was applied in 25 consecutive obese patients who had unsatisfactory fetal imaging by the standard transabdominal approach. The most frequent reason for incomplete fetal survey by the standard transabdominal approach was unsatisfactory imaging of the fetal heart (19 of 25 cases, 76%). The transumbilical approach resulted in improved resolution and satisfactory cardiac examination in 18 of these 19 cases (95%). In two cases, color and pulsed Doppler interrogation of intrafetal vessels become possible. A complete fetal survey was accomplished in 96% of the cases.

Maternal obesity is a potential source of error in mid‐trimester ultrasound estimation of gestational age

“…However, the association between obesity and postponed EDD did not change over the study period. The use of harmonic imaging and a transumbilical approach, recommended for use in obese women 26 , may also have varied between sonographers.…”

Obesity and Pregnancy

“…Very frequently incomplete cardiac examinations are cited as a reason for incomplete fetal surveys. Of the 19 complete cardiac examinations that were performed in this study, 18 became possible with the transumbilical approach and the overall visualization of organ systems was improved in 24 of the 25 (96%) cases (14).…”

The impact of maternal obesity on midtrimester sonographic visualization of fetal cardiac and craniospinal structures

“…13 However, sonographic visualization of fetal structures is adversely affected by the size of the body fat layer and thus the degree of maternal obesity. 14,15 The impact of obesity on the quality of prenatal ultrasound examination was described by Wolfe et al, 16 in 1990, who found a greater risk for suboptimal visualization only when body mass index (BMI, kg/m 2 ) was above the 90th percentile. Although this finding (a decreased ability to visualize fetal structures with maternal obesity) was described over 14 y ago, quantification of this effect based on the severity of obesity using National Institute of Health (NIH) guidelines 17 is not well defined.…”