RESUMEN
PURPOSE: Ductus venosus (DV) Doppler velocimetry reflects fetal cardiac function. Gestational diabetes mellitus (GDM) is assumed to impair cardiac function due to fetal hyperglycemia. The purpose of this study was to assess the ability of DV Doppler to predict an adverse perinatal outcome (APO) in term pregnancies with GDM. METHODS: This is a retrospective cohort study including GDM pregnancies of singleton, non-anomalous fetuses without any signs of placental dysfunction. All GDM women who primarily had a vaginal delivery attempt and in which DV Doppler was examined from 37+0 weeks on were included. Receiver operating characteristic curve (ROC) analyses were performed to assess the predictive value of DV pulsatility index (DV-PI) regarding a composite APO (CAPO). Furthermore, a subgroup analysis was performed regarding the presence of a large-for-gestational-age (LGA) newborn. RESULTS: A total of n=89 cases were included. Overall, CAPO occurred in 26 out of 89 cases (29.2%). All DV Doppler examinations showed a positive A wave. DV-PI was>95th percentile in 8 out of 89 cases (9%). Overall, ROC analysis showed no significant association of DV-PI with CAPO (AUC=0.523, p=0.735). However, regarding individual APO parameters, ROC analysis showed a significant association of DV-PI with 5th-min AGPAR (AUC=0.960, p=0.027), which was not confirmed after exclusion of LGA cases. CONCLUSION: In GDM pregnancies at term, DV Doppler sonography seems to have no benefit for APO prediction.
RESUMEN
Importance: Astronauts on International Space Station missions demonstrate adverse neuro-ocular changes. Reversing a negative translaminar pressure gradient (TLPG) by modulating cerebral blood flow, decreasing intracranial pressure, or increasing intraocular pressure (IOP) has been proposed as potential intervention for spaceflight-associated neuro-ocular syndrome (SANS). Objective: To examine whether exercise (resistance, moderate-intensity aerobic, and high-intensity aerobic) or artificially increasing IOP is associated with modulated cerebro-ocular hemodynamic and pressure changes during head-down tilt (HDT), an analogue of spaceflight, in healthy adults. Design, Setting, and Participants: A single-center investigation was conducted at Johnson Space Center, Houston, Texas, from January 1, 2014, to December 31, 2016, in 20 healthy men. Exposure: On 3 separate days, participants rested supine, were tilted to -15° HDT, and then completed 1 of 3 experimental exercise conditions (moderate-intensity aerobic, resistance, or high-intensity interval aerobic). A subset of 10 participants wore swimming goggles on all days. Main Outcomes and Measures: Applanation rebound tonometry was used to noninvasively assess IOP, and compression sonography was used to assess internal jugular venous pressure (IJVP). Estimated TLPG was calculated as the difference between IOP and IJVP. Cerebral inflow and outflow were measured in extracranial arteries using color-coded duplex ultrasonography. Results: Twenty men participated in the study (mean [SD] age, 36 [9] years). Compared with supine IOP (mean [SD], 19.3 [3.7] mm Hg), IJVP (mean [SD], 21.4 [6.0] mm Hg), and estimated TLPG (mean [SD], -2.1 [7.0] mm Hg), -15° HDT was associated with increased IOP (mean difference, 2.3 mm Hg; 95% CI, 1.4-3.3 mm Hg; P < .001) and IJVP (mean difference, 10.5 mm Hg; 95% CI, 8.9-12.2 mm Hg; P < .001) and with decreased TLPG (mean difference, -8.2 mm Hg; 95% CI, -10.1 to -6.3 mm Hg; P < .001). Exercise (regardless of modality) at -15° HDT was associated with decreased IOP (mean difference, -1.6 mm Hg; 95% CI, -2.6 to -0.6 mm Hg; P = .002) and TLPG (mean difference, -3.5 mm Hg; 95% CI, -6.2 to -0.7 mm Hg; P = .01) compared with rest. Both IOP (mean difference, 2.9 mm Hg; 95% CI, 0.7-5.1 mm Hg; P = .01) and TLPG (mean difference, 5.1 mm Hg; 95% CI, 0.8-9.4 mm Hg; P = .02) were higher in participants who wore swimming goggles compared with those not wearing goggles. Conclusions and Relevance: In this study, exercise was associated with decreased IOP and estimated translaminar pressure gradient in a spaceflight analogue of HDT. The addition of swimming goggles was associated with increased IOP and TLPG in HDT. Further evaluation in spaceflight may be warranted to determine whether modestly increasing IOP is an effective SANS countermeasure.