Browsing by Subject "Fetal hypoxia"

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    Maternal Oxygen Supplementation Compared With Room Air for Intrauterine Resuscitation: A Systematic Review and Meta-analysis
    (American Medical Association, 2021) Raghuraman, Nandini; Temming, Lorene A.; Doering, Michelle M.; Stoll, Carolyn R.; Palanisamy, Arvind; Stout, Molly J.; Colditz, Graham A.; Cahill, Alison G.; Tuuli, Methodius G.; Obstetrics and Gynecology, School of Medicine
    Importance: Supplemental oxygen is commonly administered to pregnant women at the time of delivery to prevent fetal hypoxia and acidemia. There is mixed evidence on the utility of this practice. Objective: To compare the association of peripartum maternal oxygen administration with room air on umbilical artery (UA) gas measures and neonatal outcomes. Data sources: Ovid MEDLINE, Embase, Scopus, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials were searched from February 18 to April 3, 2020. Search terms included labor or obstetric delivery and oxygen therapy and fetal blood or blood gas or acid-base imbalance. Study selection: Studies were included if they were randomized clinical trials comparing oxygen with room air at the time of scheduled cesarean delivery or labor in patients with singleton, nonanomalous pregnancies. Studies that did not collect paired umbilical cord gas samples or did not report either UA pH or UA Pao2 results were excluded. Data extraction and synthesis: Data were extracted by 2 independent reviewers. The analysis was stratified by the presence or absence of labor at the time of randomization. Data were pooled using random-effects models. Main outcomes and measures: The primary outcome for this review was UA pH. Secondary outcomes included UA pH less than 7.2, UA Pao2, UA base excess, 1- and 5-minute Apgar scores, and neonatal intensive care unit admission. Results: The meta-analysis included 16 randomized clinical trials (n = 1078 oxygen group and n = 974 room air group). There was significant heterogeneity among the studies (I2 = 49.88%; P = .03). Overall, oxygen administration was associated with no significant difference in UA pH (weighted mean difference, 0.00; 95% CI, -0.01 to 0.01). Oxygen use was associated with an increase in UA Pao2 (weighted mean difference, 2.57 mm Hg; 95% CI, 0.80-4.34 mm Hg) but no significant difference in UA base excess, UA pH less than 7.2, Apgar scores, or neonatal intensive care unit admissions. Umbilical artery pH values remained similar between groups after accounting for the risk of bias, type of oxygen delivery device, and fraction of inspired oxygen. After stratifying by the presence or absence of labor, oxygen administration in women undergoing scheduled cesarean delivery was associated with increased UA Pao2 (weighted mean difference, 2.12 mm Hg; 95% CI, 0.09-4.15 mm Hg) and a reduction in the incidence of UA pH less than 7.2 (relative risk, 0.63; 95% CI, 0.43-0.90), but these changes were not noted among those in labor (Pao2: weighted mean difference, 3.60 mm Hg; 95% CI, -0.30 to 7.49 mm Hg; UA pH<7.2: relative risk, 1.34; 95% CI, 0.58-3.11). Conclusions and relevance: This systematic review and meta-analysis suggests that studies to date showed no association between maternal oxygen and a clinically relevant improvement in UA pH or other neonatal outcomes.
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    Noninvasive Biomarkers for Cardiovascular Dysfunction Programmed in Male Offspring of Adverse Pregnancy
    (Wolters Kluwer, 2021) Lakshman, Rama; Spiroski, Ana-Mishel; McIver, Lauren B.; Murphy, Michael P.; Giussani, Dino A.; Surgery, School of Medicine
    Work in preclinical animal models has established that pregnancy complicated by chronic fetal hypoxia and oxidative stress programmes cardiovascular dysfunction in adult offspring. Translating this to the human condition comes with challenges, including the early diagnosis of affected individuals to improve clinical outcomes. We hypothesize that components of programmed cardiovascular dysfunction in offspring can be identified in vivo via analysis of blood pressure variability and heart rate variability and that maternal treatment with the mitochondria-targeted antioxidant MitoQ is protective. Pregnant rats were exposed to normoxia or hypoxia (13% O2) ±MitoQ (500 μM in water), from 6 to 20 days gestation. Offspring were maintained in normoxia postnatally. At 16 weeks of age, 1 male per litter was instrumented with vascular catheters and a femoral blood flow probe under isoflurane anesthesia. After recovery, arterial blood pressure and femoral flow were recorded in conscious, free-moving rats and analyzed. Offspring of hypoxic pregnancy had (1) increased very-low-frequency blood pressure variability (A) and heart rate variability (B), indices consistent with impaired endothelial function and (2) increased heart rate variability low/high-frequency ratio (C) and low-frequency blood pressure variability (D), indices of cardiac and vascular sympathetic hyperreactivity, respectively. MitoQ ameliorated A and B but not C and D. We show that asymptomatic cardiovascular dysfunction in adult offspring programmed by hypoxic pregnancy can be diagnosed in vivo by blood pressure variability and heart rate variability, suggesting that these noninvasive biomarkers could be translated to the clinical setting. MitoQ protected against programmed endothelial dysfunction but not sympathetic hyperreactivity, highlighting the divergent programming mechanisms involved.