Association of Maternal Comorbidity Burden With Cesarean Birth Rate Among Nulliparous, Term, Singleton, Vertex Pregnancies.

IMPORTANCE: Cesarean birth rate among nulliparous, term, singleton, vertex (NTSV) pregnancies is a standard quality measure in obstetrical care. There are limited data on how the number and type of preexisting conditions affect mode of delivery among primigravidae, and it is also uncertain how maternal comorbidity burden differs across racial and ethnic groups and whether this helps to explain disparities in the NTSV cesarean birth rate. OBJECTIVE: To determine the association between obstetric comorbidity index (OB-CMI) score and cesarean delivery among NTSV pregnancies and to evaluate whether disparities in mode of delivery exist based on race and ethnicity group after adjusting for covariate factors. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study of deliveries between January 2019 and December 2021 took place across 7 hospitals within a large academic health system in New York and included all NTSV pregnancies identified in the electronic medical record system. Exclusion criteria were fetal demise and contraindication to labor. EXPOSURE: The OB-CMI score. Covariate factors assessed included race and ethnicity group (American Indian or Alaska Native, Asian or Pacific Islander, Hispanic, non-Hispanic Black, non-Hispanic White, other or multiracial, and declined or unknown), public health insurance, and preferred language. MAIN OUTCOME AND MEASURES: Cesarean delivery. RESULTS: A total of 30 253 patients (mean [SD] age, 29.8 [5.4] years; 100% female) were included. Non-Hispanic White patients constituted the largest race and ethnicity group (43.7%), followed by Hispanic patients (16.2%), Asian or Pacific Islander patients (14.6%), and non-Hispanic Black patients (12.2%). The overall NTSV cesarean birth rate was 28.5% (n = 8632); the rate increased from 22.1% among patients with an OB-CMI score of 0 to greater than 55.0% when OB-CMI scores were 7 or higher. On multivariable mixed-effects logistic regression modeling, there was a statistically significant association between OB-CMI score group and cesarean delivery; each successive OB-CMI score group had an increased risk. Patients with an OB-CMI score of 4 or higher had more than 3 times greater odds of a cesarean birth (adjusted odds ratio, 3.14; 95% CI, 2.90-3.40) than those with an OB-CMI score of 0. Compared with non-Hispanic White patients, nearly all other race and ethnicity groups were at increased risk for cesarean delivery, and non-Hispanic Black patients were at highest risk (adjusted odds ratio, 1.43; 95% CI, 1.31-1.55). CONCLUSIONS AND RELEVANCE: In this cross-sectional study of patients with NTSV pregnancies, OB-CMI score was positively associated with cesarean birth. Racial and ethnic disparities in this metric were observed. Although differences in the prevalence of preexisting conditions were seen across groups, this did not fully explain variation in cesarean delivery rates, suggesting that unmeasured clinical or nonclinical factors may have influenced the outcome.

Noninvasive monitoring of uterine electrical activity among patients with obesity: a new external monitoring device.

BACKGROUND: Tocodynamometry is a common, noninvasive tool used to measure contraction frequency; however, its utility is often limited in patients with obesity. An intrauterine pressure catheter provides a more accurate measurement of uterine contractions but requires ruptured membranes, limiting its utility during early latent labor. Electrical uterine myography has shown promise as a noninvasive contraction monitor with efficacy similar to that of the intrauterine pressure catheter; however, its efficacy has not been widely studied in the obese population. OBJECTIVE: This study aimed to validate the accuracy of electrical uterine myography by comparing it with tocodynamometry and intrauterine pressure catheters among laboring patients with obesity. STUDY DESIGN: This was a prospective observational study from February 2017 to April 2018 of patients with obesity, aged 18 years or older, who were admitted to the labor unit with viable singleton pregnancies and no contraindications for electromyography. Patients were monitored simultaneously with electrical myography and tocodynamometry or intrauterine catheter for more than 30 minutes. Two blinded obstetricians reviewed the tracings. The outcomes of interest were continuous and interpretable tracing, number of contractions, and timing and duration of contractions, interpreted as point estimates and associated 95% confidence intervals. RESULTS: A total of 110 patients were enrolled (65 tocodynamometry, 55 intrauterine catheter). Electrical myography was significantly more interpretable during a 30-minute tracing (P=.001) and detected 39% more contractions than tocodynamometry (P<.0001; 95% confidence interval, 23%-57%), whereas there was no difference in the interpretability of tracings or number of contractions between electrical myography and an intrauterine catheter (P=.16; 95% confidence interval, -0.19 to 1.19). Patients who underwent simultaneous monitoring preferred the electrical myography device over tocodynamometry. CONCLUSION: Electrical uterine myography is superior to tocodynamometry in the detection of intrapartum uterine contraction monitoring and comparable with internal contraction monitoring.

Cation-π interactions of methylated ammonium ions: a quantum mechanical study.

Cation-π interactions of methylated ammonium ions play a key role in a broad range of biochemical systems. These include methyl-lysine binding proteins which bind to methylated sites on histone proteins, lysine demethylase enzymes which demethylate these sites, and neurotransmitter receptor complexes which bind choline-derived ligands. Recognition in these systems is achieved through an 'aromatic cage' motif in the binding site. Here we use high-level quantum mechanical calculations to address how cation-π interactions of methylated ammonium ions are modulated by a change in methylation state and interaction geometry. We survey methyl-lysine and choline-derived complexes in the Protein Databank to validate our results against available structural data. A quantitative description of cation-π interactions of methylated ammonium systems is critical to structure-based efforts to target methyl-lysine binding proteins and demethylase enzymes in the treatment of unregulated transcriptional control, and neurotransmitter receptors in the treatment of neurological disease. It is our hope that our work will serve as a benchmark for the development of physical chemistry based force fields that can accurately model the contribution of cation-π interactions to binding and specificity in these systems.