Impact of fetal trisomy 21 on umbilical artery Doppler indices

Objectives - Umbilical artery (UA) Doppler indices are surrogate measures of placental function, most commonly used to assess fetal wellbeing in pregnancies with fetal growth restriction. Fetuses with trisomy 21 (t21) are reported to have elevated UA Doppler indices, but reference percentiles are currently lacking for this population. We hypothesized that gestational age-specific values of UA Doppler indices in pregnancies complicated by t21 will be elevated compared to established percentiles based on euploid pregnancies. We aimed to assess UA Doppler indices longitudinally in fetuses with t21 in order to demonstrate Doppler patterns across gestation in this population, compare them with euploid fetuses, and investigate their association with pregnancy outcomes. Methods - We conducted a retrospective cohort study of singleton pregnancies with confirmed fetal t21 who underwent UA Doppler surveillance antenatally from January 2012 to August 2019. UA Doppler indices, including systolic/diastolic (S/D) ratio, pulsatility index (PI), and resistance index (RI) were extracted from ultrasound reports or directly from ultrasound images. UA S/D, PI, and RI percentiles by gestational week were created from available observations from our cohort via a data-driven approach using a generalized additive model. A secondary analysis was run to statistically compare t21 values to established percentiles based on observations from a historical population of euploid fetuses. Results - UA Doppler measurements from 86 t21 fetuses and 130 euploid fetuses were included in our analysis. Median (IQR) maternal age in t21 pregnancies and euploid pregnancies were 35 years (29–38) and 30 years (27–33), respectively. As in euploid fetuses, we found a negative association between Doppler indices and gestational age in the t21 fetuses. Maternal tobacco use, obesity, or chronic hypertension had no significant effect on UA Doppler indices. As hypothesized, values for UA S/D ratio, PI, and RI at the 2.5th, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97.5th percentiles by gestational week were significantly higher in t21 fetuses compared to euploid fetuses (p Conclusions - At each week of gestation, UA Doppler indices in t21 fetuses were significantly higher than established percentiles from a euploid population. Reference intervals based on euploid fetuses may therefore not be appropriate for antenatal surveillance of fetuses with t21. Prospective studies are needed to investigate the role and impact of serial UA Doppler velocimetry in the surveillance of pregnancies complicated by fetal t21

Impact of fetal trisomy 21 on umbilical artery Doppler indices

Umbilical artery (UA) Doppler indices are surrogate measures of placental function, most commonly used to assess fetal wellbeing in pregnancies with fetal growth restriction. Fetuses with trisomy 21 (t21) are reported to have elevated UA Doppler indices, but reference percentiles are currently lacking for this population. We hypothesized that gestational age-specific values of UA Doppler indices in pregnancies complicated by t21 will be elevated compared to established percentiles based on euploid pregnancies. We aimed to assess UA Doppler indices longitudinally in fetuses with t21 in order to demonstrate Doppler patterns across gestation in this population, compare them with euploid fetuses, and investigate their association with pregnancy outcomes. We conducted a retrospective cohort study of singleton pregnancies with confirmed fetal t21 who underwent UA Doppler surveillance antenatally from January 2012 to August 2019. UA Doppler indices, including systolic/diastolic (S/D) ratio, pulsatility index (PI), and resistance index (RI) were extracted from ultrasound reports or directly from ultrasound images. UA S/D, PI, and RI percentiles by gestational week were created from available observations from our cohort via a data-driven approach using a generalized additive model. A secondary analysis was run to statistically compare t21 values to established percentiles based on observations from a historical population of euploid fetuses. UA Doppler measurements from 86 t21 fetuses and 130 euploid fetuses were included in our analysis. Median (IQR) maternal age in t21 pregnancies and euploid pregnancies were 35 years (29–38) and 30 years (27–33), respectively. As in euploid fetuses, we found a negative association between Doppler indices and gestational age in the t21 fetuses. Maternal tobacco use, obesity, or chronic hypertension had no significant effect on UA Doppler indices. As hypothesized, values for UA S/D ratio, PI, and RI at the 2.5th, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97.5th percentiles by gestational week were significantly higher in t21 fetuses compared to euploid fetuses (pp  At each week of gestation, UA Doppler indices in t21 fetuses were significantly higher than established percentiles from a euploid population. Reference intervals based on euploid fetuses may therefore not be appropriate for antenatal surveillance of fetuses with t21. Prospective studies are needed to investigate the role and impact of serial UA Doppler velocimetry in the surveillance of pregnancies complicated by fetal t21.</p

Systematic review of international studies evaluating MDRD and CKD-EPI estimated glomerular filtration rate (eGFR) equations in Black adults.

Use of race adjustment in estimating glomerular filtration rate (eGFR) has been challenged given concerns that it may negatively impact the clinical care of Black patients, as it results in Black patients being systematically assigned higher eGFR values than non-Black patients. We conducted a systematic review to assess how well eGFR, with and without race adjustment, estimates measured GFR (mGFR) in Black adults globally. A search across multiple databases for articles published from 1999 to May 2021 that compared eGFR to mGFR and reported outcomes by Black race was performed. We included studies that assessed eGFR using the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPICr) creatinine equations. Risk of study bias and applicability were assessed with the QUality Assessment of Diagnostic Accuracy Studies-2. Of 13,167 citations identified, 12 met the data synthesis criteria (unique patient cohorts in which eGFR was compared to mGFR with and without race adjustment). The studies included patients with and without kidney disease from Africa (n = 6), the United States (n = 3), Europe (n = 2), and Brazil (n = 1). Of 11 CKD-EPI equation studies, all assessed bias, 8 assessed accuracy, 6 assessed precision, and 5 assessed correlation/concordance. Of 7 MDRD equation studies, all assessed bias, 6 assessed accuracy, 5 assessed precision, and 3 assessed correlation/concordance. The majority of studies found that removal of race adjustment improved bias, accuracy, and precision of eGFR equations for Black adults. Risk of study bias was often unclear, but applicability concerns were low. Our systematic review supports the need for future studies to be conducted in diverse populations to assess the possibility of alternative approaches for estimating GFR. This study additionally provides systematic-level evidence for the American Society of Nephrology-National Kidney Foundation Task Force efforts to pursue other options for GFR estimation