The AccuFlow sensor: a novel digital health tool to assess intrapartum blood loss at cesarean delivery.

OBJECTIVES: During obstetric hemorrhage, peripheral vasoconstriction maintains heart rate and blood pressure until compensatory mechanisms are overwhelmed and patients deteriorate rapidly. Real-time perfusion measurements could quantify vasoconstriction, improving early recognition of hemorrhage and facilitating early intervention to reduce morbidity and mortality. The AccuFlow device makes rapid, non-invasive, quantitative measurements of perfusion, but has not been studied for hemorrhage detection or used in surgical settings. This study evaluated feasibility, tolerability, and preliminary efficacy of the AccuFlow for assessment of blood loss at cesarean delivery (CD). METHODS: In this pilot study, sensors were applied to the wrist, forearm, bicep, and chest wall of 25 patients undergoing scheduled CD. Postoperatively, sensors were removed and patients rated the AccuFlow and the standard anesthesia monitoring equipment on a validated comfort rating scale for wearable computers (CRS). Blood loss was estimated by the surgical team (EBL) and calculated from change in hematocrit, weight, and height (CBL). CRS scores were compared via Wilcoxon signed ranks tests. Coefficients of correlation between sensor readings and CBL, and between EBL and CBL, were compared using Fisher's R-to-z transformation. RESULTS: There were no safety events; no participants requested device removal. CRS ratings of the AccuFlow and the standard monitoring equipment were similar (7.2 vs. 8.8, p=0.25). Change in wrist perfusion from delivery to dressing placement was more strongly correlated with CBL than was EBL (R=-0.48 vs. R=0.087, p=0.03). CONCLUSIONS: The AccuFlow sensor is well-tolerated and shows promise in detecting intrapartum hemorrhage, though larger studies are needed.

Risk factors for respiratory distress syndrome among high-risk early-term and full-term deliveries.

OBJECTIVE: To identify whether risk factors for respiratory distress syndrome (RDS) differ between early-term and full-term births. STUDY DESIGN: This is a secondary analysis of a large NIH-funded retrospective cohort study including patients who delivered at a tertiary-care obstetric hospital between January 2002 and March 2013 with comorbid diabetes, hypertensive disorders, and/or fetal growth restriction (FGR). Pregnancies complicated by severe preeclampsia and multifetal gestations were excluded. Maternal characteristics, delivery information, and neonatal information were abstracted by trained clinicians blinded to the comorbidity leading to study inclusion. In this secondary analysis of the infant health outcomes of pregnancies with one or more of the qualifying conditions, risk factors for RDS among neonates born early term (37w0d-38w6d gestation) were compared to risk factors for RDS among full-term neonates (39w0d-40w6d). RESULTS: Among 10,532 singleton newborns, there were 99 cases of early-term RDS (0.94%) and 95 cases of full-term RDS (0.90%). Maternal demographics were similar between those with and without RDS in both groups. Among early-term infants, lower gestational age, presence of meconium, non-spontaneous labor, and cesarean delivery were positively associated with RDS, whereas hypertensive disorders, diabetes, FGR, and many other comorbid delivery conditions were not. The strongest risk factor for RDS among early-term infants was delivery via cesarean (RR 1.98, 95% CI 1.31, 3.01). Among full-term neonates, cesarean delivery was also positively associated with RDS, although presence of meconium, chorioamnionitis, and endometritis were all stronger risk factors with RRs >2.0. CONCLUSIONS: In this cohort of high-risk term deliveries, maternal demographics and comorbidities were found not to be associated with increased risk for RDS, but novel risk factors for RDS after 37 weeks' gestation - chorioamnionitis and endometritis - were identified. A focus on preventing infectious comorbidities may help reduce incidence of RDS at full-term.Key PointsRDS risk factors vary by gestational age.Novel risk factors for RDS at full-term identified.Intrauterine inflammation associated with RDS at term.

Association of admission unit and birth satisfaction during induction of labor.

OBJECTIVE: As induction of labor (IOL) becomes more common, hospitals must adjust to accommodate longer length of stays on labor and delivery. An alternative to reduce the length of time spent on labor and delivery during an IOL is to perform cervical ripening on an antepartum unit. However, this may affect patient satisfaction and knowledge about the birthing process. This study aimed to evaluate whether cervical ripening conducted in an antepartum unit, rather than on a labor and delivery unit, was associated with changes in patient satisfaction with birth experience and baseline knowledge about IOL. Additionally, the study aimed to understand how patients would prefer to receive education on the IOL process. METHODS: This prospective observational study recruited English and Spanish-speaking patients at or after 39 weeks and 0 days gestation who were admitted for IOL. Consenting patients completed a preliminary survey containing sociodemographic and obstetric information as well as a previously validated survey on IOL knowledge on admission. Within 48 h of delivery, patients completed a follow-up survey including a validated birth satisfaction survey, the Birth Satisfaction Scale-Revised, and questions eliciting their preferred IOL education method. Data analyses compared patients who were admitted to antepartum for IOL to those admitted directly to labor and delivery. Multivariate analyses adjusted for sociodemographic and obstetric differences between the two groups. The primary outcomes were scores on the Birth Satisfaction Scale-Revised and on a test examining IOL knowledge. Secondary outcomes included preferred method of IOL education, obstetric outcomes, and neonatal outcomes. RESULTS: A total of 277 eligible patients were approached from October 2020 to March 2021. Of the 216 (78%) that consented, 159 (74%) completed the follow-up survey and were subsequently included in this analysis. Individuals admitted directly to antepartum (n = 122) more commonly self-identified as Latina, Latin American, or Hispanic (27.9% vs. 8.1%, p = .01) and were nulliparous (68.0% vs. 21.6%, p < .001) compared to participants admitted to labor and delivery for IOL (n = 37). Patients admitted to labor and delivery were more likely to undergo elective induction (29.7% vs. 9.8%, p = .006). Admission unit was not associated with differences in birth satisfaction scores or obstetric or neonatal outcomes. However, after controlling for potential confounders, patients admitted to the antepartum unit correctly answered a greater percentage of questions assessing IOL knowledge compared to patients admitted to labor and delivery (73.9% vs. 62.3%, adjusted mean difference (aMD) 12.6 [95% CI 7.2, 18.0]). Patients in both groups indicated preference for reviewing an induction checklist with a provider during prenatal care (59.1%) or using a technology-based intervention (37.1%) over attending in-person classes (3.1%) to learn more about IOL. CONCLUSION: Unit of admission for IOL is not associated with satisfaction with birth experience but is associated with patient knowledge of IOL. This suggests that IOL may be initiated in less acute units than labor and delivery without altering birth experience and may potentially allow for increased patient knowledge. Additionally, IOL checklists or technology-based education may help to further increase patient knowledge about IOL.