Family medicine physician identification of obstetric lacerations: a US national survey.

INTRODUCTION AND HYPOTHESIS: We evaluated family medicine obstetric providers' identification and categorization of vaginal delivery lacerations in the USA. We hypothesized that there would be inaccuracy in family medicine physicians' identification of vaginal delivery injuries, similar to our previous studies of midwives and obstetricians (OBs). METHODS: We included clinically active physicians who attended deliveries within 2 years and evaluated their identification and categorization of delivery lacerations using descriptive text and visual images. We asked about their education on this topic and how they document lacerations in the labor and delivery record. RESULTS: We analyzed 250 completed responses (70% of opened surveys). Fifty-five percent of respondents characterized their obstetric laceration training as "good" or "excellent" and half previously had education on obstetric lacerations. The median accuracy overall for the classification and identification of perineal lacerations was 78% (IQR 56-91%). Respondents frequently mischaracterized nonperineal lacerations. Few respondents (36%) reported using the third-degree injury subclassification system. In adjusted analysis, the highest scoring respondents were board certified in family medicine, with fewer years in practice, and a higher obstetric volume. CONCLUSIONS: Obstetric laceration diagnoses may be inaccurate, which could influence perinatal quality and patient outcomes. We found gaps in knowledge similar to previous reports on midwives and obstetricians in the USA. These data suggest a need for increased education and training on obstetric injuries, perhaps especially for physicians with less obstetric activity. Improved categorization and identification of vaginal delivery trauma can impact management and improve women's postpartum care and long-term pelvic floor outcomes.

Diagnosis, management and training in perineal trauma: a UK national survey of obstetricians.

INTRODUCTION AND HYPOTHESIS: Perineal trauma during vaginal delivery is very common. Training in diagnosis and repair of trauma, including obstetric anal sphincter injuries, varies in the UK. We aimed to investigate the current knowledge and training received by obstetric physicians. METHODS: A national, validated survey was conducted online, using Qualtrics. The National Trainees Committee distributed the survey. It was also sent directly to consultants via email. RESULTS: A total of 302 physicians completed the survey and were included in the analysis. 3.9% of participants described their training in obstetric perineal trauma as "very poor" or "poor". 20.5% said they have not received training. 8.6% of physicians practising for more than 10 years had not had training for over 10 years. 70.5% responded "somewhat agree" or "strongly agree" when asked if they would like more training. Identification of first, second, third-, and fourth-degree tears from images and descriptions was very good (more than 80% correct for all categories). Classification of other perineal trauma was less consistent, with many incorrectly using the Sultan Classification. "Manual perineal support" and "Controlled or guided delivery" were the most frequently selected methods for the prevention of obstetric anal sphincter injury (OASI). CONCLUSIONS: Training experience for physicians in obstetric perineal trauma varies. Further improvement in training and education in perineal trauma, particularly in OASI, is needed for physicians. Perineal trauma that is not included in the Sultan Classification is often misclassified.

The Pathophysiology of Labor Dystocia: Theme with Variations.

Abnormally prolonged labor, or labor dystocia, is a common complication of parturition. It is the indication for about half of unplanned cesarean deliveries in low-risk nulliparous women. Reducing the rate of unplanned cesarean birth in the USA has been a public health priority over the last two decades with limited success. Labor dystocia is a complex disorder due to multiple causes with a common clinical outcome of slow cervical dilation and fetal descent. A better understanding of the pathophysiologic mechanisms of labor dystocia could lead to new clinical opportunities to increase the rate of normal vaginal delivery, reduce cesarean birth rates, and improve maternal and neonatal health. We conducted a literature review of the causes and pathophysiologic mechanisms of labor dystocia. We summarize known mechanisms supported by clinical and experimental data and newer hypotheses with less supporting evidence. We review recent data on uterine preparation for labor, uterine contractility, cervical preparation for labor, maternal obesity, cephalopelvic disproportion, fetal malposition, intrauterine infection, and maternal stress. We also describe current clinical approaches to preventing and managing labor dystocia. The variation in pathophysiologic causes of labor dystocia probably limits the utility of current general treatment options. However, treatments targeting specific underlying etiologies could be more effective. We found that the pathophysiologic basis of labor dystocia is under-researched, offering wide opportunities for translational investigation of individualized labor management, particularly regarding uterine metabolism and fetal position. More precise diagnostic tools and individualized therapies for labor dystocia might lead to better outcomes. We conclude that additional knowledge of parturition physiology coupled with rigorous clinical evaluation of novel biologically directed treatments could improve obstetric quality of care.

Obstetric anal sphincter injuries and other delivery trauma: a US national survey of obstetrician-gynecologists.

INTRODUCTION AND HYPOTHESIS: Obstetric lacerations complicate the majority of deliveries. The application of standardized guidelines for assessing delivery trauma has not been assessed thoroughly in the United States. We recently identified gaps in US midwives' clinical assessment of delivery trauma. We conducted a cross-sectional national survey of practicing obstetricians in the USA to characterize their classification of obstetric lacerations. We hypothesized that attending obstetricians' identification and diagnosis of delivery trauma would be similar to our findings for midwives with frequent inaccuracy. METHODS: We recruited clinically active obstetricians through the Pregnancy-Related Care Research Network. We asked participants to classify (from written definitions) and diagnose (from standard illustrations) common forms of vaginal delivery trauma using the widely employed perineal laceration degree system. We performed bivariate analysis of high- and low-scoring respondents and logistic regression to model characteristics associated with higher diagnostic accuracy. RESULTS: Of the 162 respondents who started the survey, 76% (123) were included for analysis (22% of solicited emails). Overall, we found wide variation in response accuracy with as few as 62% of respondents correctly classifying certain types of lacerations. Only 49 out of 123 (40%) use the Sultan third-degree subclassification system and 67 out of 123 (52%) continue to use the midline/median approach for episiotomies. Providers reporting fewer deliveries per month and fewer publicly insured patients earned higher scores. CONCLUSIONS: Obstetricians in a nationally representative US perinatal provider network inconsistently identify perineal and nonperineal lacerations. We found important clinical knowledge gaps, suggesting that vaginal delivery diagnoses in obstetric quality studies and pelvic floor research might be inaccurate.

A Nested Case-Control Study of Allopregnanolone and Preterm Birth in the Healthy Start Cohort.

Context: Chronic stress is a risk factor for preterm birth; however, objective measures of stress in pregnancy are limited. Maternal stress biomarkers may fill this gap. Steroid hormones and neurosteroids such as allopregnanolone (ALLO) play important roles in stress physiology and pregnancy maintenance and therefore may be promising for preterm birth prediction. Objective: We evaluated maternal serum ALLO, progesterone, cortisol, cortisone, pregnanolone, and epipregnanolone twice in gestation to evaluate associations with preterm birth. Methods: We performed a nested case-control study using biobanked fasting serum samples from the Healthy Start prebirth cohort. We included healthy women with a singleton pregnancy and matched preterm cases with term controls (1:1; N = 27 per group). We used a new HPLC-tandem mass spectrometry assay to quantify ALLO and five related steroids. We used ANOVA, Fisher exact, χ2, t test, and linear and logistic regression as statistical tests. Results: Maternal serum ALLO did not associate with preterm birth nor differ between groups. Mean cortisol levels were significantly higher in the preterm group early in pregnancy (13w0d-18w0d; P < 0.05) and higher early pregnancy cortisol associated with increased odds of preterm birth (at 13w0d; odds ratio, 1.007; 95% CI, 1.0002-1.014). Progesterone, cortisone, pregnanolone, and epipregnanolone did not associate with preterm birth. Conclusion: The findings from our pilot study suggest potential utility of cortisol as a maternal serum biomarker for preterm birth risk assessment in early pregnancy. Further evaluation using larger cohorts and additional gestational timepoints for ALLO and the other analytes may be informative.

Metabolomics in Prenatal Medicine: A Review.

Pregnancy is a complicated and insidious state with various aspects to consider, including the well-being of the mother and child. Developing better non-invasive tests that cover a broader range of disorders with lower false-positive rates is a fundamental necessity in the prenatal medicine field, and, in this sense, the application of metabolomics could be extremely useful. Metabolomics measures and analyses the products of cellular biochemistry. As a biomarker discovery tool, the integrated holistic approach of metabolomics can yield new diagnostic or therapeutic approaches. In this review, we identify and summarize prenatal metabolomics studies and identify themes and controversies. We conducted a comprehensive search of PubMed and Google Scholar for all publications through January 2020 using combinations of the following keywords: nuclear magnetic resonance, mass spectrometry, metabolic profiling, prenatal diagnosis, pregnancy, chromosomal or aneuploidy, pre-eclampsia, fetal growth restriction, pre-term labor, and congenital defect. Metabolite detection with high throughput systems aided by advanced bioinformatics and network analysis allowed for the identification of new potential prenatal biomarkers and therapeutic targets. We took into consideration the scientific papers issued between the years 2000-2020, thus observing that the larger number of them were mainly published in the last 10 years. Initial small metabolomics studies in perinatology suggest that previously unidentified biochemical pathways and predictive biomarkers may be clinically useful. Although the scientific community is considering metabolomics with increasing attention for the study of prenatal medicine as well, more in-depth studies would be useful in order to advance toward the clinic world as the obtained results appear to be still preliminary. Employing metabolomics approaches to understand fetal and perinatal pathophysiology requires further research with larger sample sizes and rigorous testing of pilot studies using various omics and traditional hypothesis-driven experimental approaches.

Cystathionine γ-lyase promotes estrogen-stimulated uterine artery blood flow via glutathione homeostasis.

During pregnancy, estrogen (E2) stimulates uterine artery blood flow (UBF) by enhancing nitric oxide (NO)-dependent vasodilation. Cystathionine γ-lyase (CSE) promotes vascular NO signaling by producing hydrogen sulfide (H2S) and by maintaining the ratio of reduced-to-oxidized intracellular glutathione (GSH/GSSG) through l-cysteine production. Because redox homeostasis can influence NO signaling, we hypothesized that CSE mediates E2 stimulation of UBF by modulating local intracellular cysteine metabolism and GSH/GSSG levels to promote redox homeostasis. Using non-pregnant ovariectomized WT and CSE-null (CSE KO) mice, we performed micro-ultrasound of mouse uterine and renal arteries to assess changes in blood flow upon exogenous E2 stimulation. We quantified serum and uterine artery NO metabolites (NOx), serum amino acids, and uterine and renal artery GSH/GSSG. WT and CSE KO mice exhibited similar baseline uterine and renal blood flow. Unlike WT, CSE KO mice did not exhibit expected E2 stimulation of UBF. Renal blood flow was E2-insensitive for both genotypes. While serum and uterine artery NOx were similar between genotypes at baseline, E2 decreased NOx in CSE KO serum. Cysteine was also lower in CSE KO serum, while citrulline and homocysteine levels were elevated. E2 and CSE deletion additively decreased GSH/GSSG in uterine arteries. In contrast, renal artery GSH/GSSG was insensitive to E2 or CSE deletion. Together, these findings suggest that CSE maintenance of uterine artery GSH/GSSG facilitates nitrergic signaling in uterine arteries and is required for normal E2 stimulation of UBF. These data have implications for pregnancy pathophysiology and the selective hormone responses of specific vascular beds.

Accuracy of obstetric laceration diagnoses in the electronic medical record.

INTRODUCTION AND HYPOTHESIS: Patient safety data including rates of obstetric anal sphincter injury (OASI) are often derived from hospital discharge codes. With the transition to electronic medical records (EMRs), we hypothesized that electronic provider-entered delivery data would more accurately document obstetric perineal injury than traditional billing/diagnostic codes. METHODS: We evaluated the accuracy of perineal laceration diagnoses after singleton vaginal deliveries during one calendar year at an American tertiary academic medical center. We reviewed the entire hospital chart to determine the most likely laceration diagnosis and compared that expert review diagnosis (ExpRD) with documentation in the EMR delivery summary (EDS) and ICD-9 diagnostic codes (IDCs). RESULTS: We retrospectively selected 354 total delivery records. OASI complicated 56 of those. 303 records (86%) were coded identically by the EDS and IDCs. Diagnoses from the IDCs and the EDS were mostly correct compared with ExpRD (sensitivity = 96%, specificity = 100%). There was no systematic over- or under-diagnosis of OASI for either the EDS (p = 0.070) or the IDCs (p = 0.447). When considering all laceration types the EDS was correct for 21 (5.9%) lacerations that were incorrect according to the IDCs. Overall, the EDS was more accurate (p < 0.05) owing to errors in IDC minor laceration diagnoses. CONCLUSIONS: Electronic medical record delivery summary data and EMR-derived diagnostic codes similarly characterize OASI. The EDS does not improve OASI reporting, but may be more accurate when considering all perineal lacerations. This assumes that providers have correctly identified and categorized the lacerations that they record in the EMR.

Estrogen Regulates Local Cysteine Metabolism in Mouse Myometrium.

Sulfur amino acid metabolism influences reproductive physiology, and transsulfuration in particular may be critical for normal cellular function. The sex hormone estrogen (E2) modulates gene expression and redox balance in some tissues by inducing the transsulfuration enzymes cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CSE). The role of sex hormones in sulfur amino acid metabolism by uterine smooth muscle is not known. Here, we show that CBS and CSE proteins increase in the mouse myometrium during estrus and diestrus, respectively, suggesting that E2 reciprocally regulates myometrial CBS and CSE expression. In ovariectomized mice, exogenous E2 upregulates CBS and downregulates CSE levels. E2 promotes CBS mRNA and protein expression but attenuates CSE protein expression without affecting CSE mRNA. This pattern of E2-stimulated changes in transsulfuration enzyme expression is specific to the uterine smooth muscle. E2 does not change vaginal or cervical expression of CBS or CSE significantly, and E2 decreases expression of CSE in the liver without affecting CBS. E2 also downregulates myometrial cysteinesulfinic acid decarboxylase (CSAD) and decreases myometrial biochemical synthesis of the gaso-transmitter hydrogen sulfide (H2S). These findings suggest that myometrial sulfur amino acid metabolism may regulate uterine redox homeostasis, with implications for the source and metabolism of myometrial cysteine in high E2 states such as estrus and pregnancy.

Identification of obstetric anal sphincter injuries (OASIs) and other lacerations: a national survey of nurse-midwives.

INTRODUCTION AND HYPOTHESIS: Clinical quality improvement relies on accurate understanding of current practice. We performed a cross-sectional national survey of certified nurse-midwives (CNMs) assessing classification and identification of obstetric anal sphincter injury (OASI) and other delivery lacerations. We hypothesized laceration diagnoses are frequently inaccurate, and delivery records for obstetric lacerations may be of questionable quality. METHODS: We emailed 6909 American College of Nurse Midwives members an internet-based survey link. Of respondents, we included clinically active CNMs who perform at least one delivery per month. We evaluated laceration knowledge and application using standard descriptive text and images and asked about processes for recording lacerations in the delivery record. RESULTS: We received 1070 (15.5%) completed surveys and 832 (77.8%) met inclusion criteria. Over 50% characterized their OASI training and ability to identify OASI as good/excellent. Most (79%) had never attended education review on OASI. The overall accuracy for classification and identification of perineal lacerations ranged from 49 to 99%. Non-perineal lacerations were frequently categorized using the perineal/OASI system. Half of respondents (51%) document their deliveries in an electronic medical record but a quarter (28%) are not personally responsible for approving delivery data. Younger participants without a doctoral degree, with self-assessed good/excellent laceration training, and caring for < 50% publicly insured patients had higher accuracy for laceration identification and diagnosis. CONCLUSIONS: We found high rates of inaccurate laceration diagnosis and inappropriate application of the perineal OASI degree system, suggesting education and training are needed. Clinical studies that rely on delivery diagnosis of OASI may not be reliable.

Maternal Amino Acid Profiles to Distinguish Constitutionally Small versus Growth-Restricted Fetuses Defined by Doppler Ultrasound: A Pilot Study.

OBJECTIVE: Fetuses measuring below the 10th percentile for gestational age may be either constitutionally small for gestational age (SGA) or have pathologic fetal growth restriction (FGR). FGR is associated with adverse outcomes; however, identification of low-risk SGA cases is difficult. We performed a pilot study evaluating maternal markers of pathologic FGR, hypothesizing there are distinct amino acid signatures that might be used for diagnosis and development of new interventions. STUDY DESIGN: This was a cohort study of healthy women with sonographic fetal estimated fetal weight <5th percentile divided into two groups based upon umbilical artery (UmA) Doppler studies or uterine artery (UtA) Doppler studies. We collected maternal blood samples prior to delivery and used ion pair reverse phase liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry to assess 44 amino acids. RESULTS: Among 14 women included, five had abnormal UmA, and three had abnormal UtA Doppler results. Those with abnormal UmA showed elevated ornithine. Those with abnormal UtA had lower dimethylglycine, isoleucine, methionine, phenylalanine, and 1-methylhistidine. CONCLUSION: We found several amino acids that might identify pregnancies affected by pathologic FGR. These findings support the feasibility of future larger studies to identify maternal metabolic approaches to accurately stratify risk for small fetuses.

Effects of resveratrol or estradiol on postexercise endothelial function in estrogen-deficient postmenopausal women.

Regular exercise enhances endothelial function in older men, but not consistently in estrogen-deficient postmenopausal women. Estradiol treatment improves basal endothelial function and restores improvements in endothelial function (flow-mediated dilation, FMD) to aerobic exercise training in postmenopausal women; however, estradiol treatment is controversial. Resveratrol, an estrogen receptor ligand, enhances exercise training effects on cardiovascular function and nitric oxide (NO) release in animal models, but impairs exercise training effects in men. We conducted a randomized cross-over, double-blinded, placebo-controlled pilot study to determine whether acute (single dose) resveratrol (250-mg tablet) or estradiol (0.05 mg/day transdermal patch) treatment enhances FMD at rest and after a single bout of moderate-intensity aerobic exercise in healthy estrogen-deficient postmenopausal women (n = 15, 58.1 ± 3.2 yr). FMD was measured before and after (30, 60, and 120 min) a 40-min bout of moderate-intensity treadmill exercise (60-75% peak heart rate) under the respective conditions (separated by 1-2 wk). FMD was higher (P < 0.05) before exercise and at all post-exercise time points in the resveratrol and estradiol conditions compared to placebo. FMD was increased from baseline by 120 min postexercise in the estradiol condition (P < 0.001), but not resveratrol or PL conditions. Consistent with our previous findings, estradiol also enhances endothelial function in response to acute endurance exercise. Although resveratrol improved basal FMD, there was no apparent enhancement of FMD to acute exercise and, therefore, may not act as an estradiol mimetic.NEW & NOTEWORTHY The benefits of endurance exercise training on endothelial function are diminished in estrogen-deficient postmenopausal women, but estradiol treatment appears to restore improvements in endothelial function in this group. We show that basal endothelial function is enhanced with both acute estradiol and resveratrol treatments in estrogen-deficient postmenopausal women, but endothelial function is only enhanced following acute endurance exercise with estradiol treatment.

Seminal Fluid Metabolomic Markers of Oligozoospermic Infertility in Humans.

Infertility affects 12-15% of couples worldwide, and male factors are the cause of nearly half of all cases. Studying seminal fluid composition could lead to additional diagnostic accuracy and a better understanding of the pathophysiology of male factor infertility. Metabolomics offers a new opportunity to evaluate biomarkers and better understand pathological mechanisms. The aim of the study was to identify new markers or therapeutic targets to improve outcomes in male factor or idiopathic infertility patients. Semen samples were obtained from 29 men with a normal spermogram test, and from 18 oligozoospermic men. Samples were processed and analyzed by Nuclear Magnetic Resonance spectroscopy and, subsequently, multivariate and univariate statistical analyses. Receiving Operator Curves (ROC) and Spearman correlations were also performed. An Orthogonal Partial Least Square Discriminant Analysis supervised multivariate model was devised to compare the groups. The levels of fructose, myo-inositol, aspartate and choline were altered. Moreover, Spearman Correlation associated fructose, aspartate and myo-inositol with the total amount of spermatozoa, total motile spermatozoa, % of immotility and % of "in situ" spermatozoic motility respectively. NMR-based metabolomics allowed the identification of a specific metabolic fingerprint of the seminal fluids of patients affected by oligozoospermia.

Effect of neuronal nitric oxide synthase serine-1412 phosphorylation on hypothalamic-pituitary-ovarian function and leptin response.

Hypothalamic neuronal nitric oxide synthase (nNOS) potentiates adult female fertility in rodents by stimulating gonadotropin releasing hormone (GnRH) secretion, which in turn promotes luteinizing hormone (LH) release and ovulation. The mechanism of hypothalamic nNOS activation is not clear but could be via nNOS serine1412 (S1412) phosphorylation, which increases nNOS activity and physiologic NO effects in other organ systems. In female rodents, hypothalamic nNOS S1412 phosphorylation reportedly increases during proestrus or upon acute leptin exposure during diestrus. To determine if nNOS S1412 regulates female reproduction in mice, we compared the reproductive anatomy, estrous cycle duration and phase proportion, and fecundity of wild-type and nNOS serine1412➔alanine (nNOSS1412A) knock-in female mice. We also measured hypothalamic GnRH and serum LH, follicle stimulating hormone (FSH), estradiol, and progesterone in diestrus mice after intraperitoneal leptin injection. Organ weights and histology were not different by genotype. Ovarian primordial follicles, antral follicles, and corpora lutea were similar for wild-type and nNOSS1412A mice. Likewise, estrous cycle duration and phase length were not different, and fecundity was unremarkable. There were no differences among genotypes for LH, FSH, estradiol, or progesterone. In contrast to prior studies, our work suggests that nNOS S1412 phosphorylation is dispensable for normal hypothalamic-pituitary-ovarian function and regular estrous cycling. These findings have important implications for current models of fertility regulation by nNOS phosphorylation.

Protein kinase A facilitates relaxation of mouse ileum via phosphorylation of neuronal nitric oxide synthase.

BACKGROUND AND PURPOSE: The enteric neurotransmitter nitric oxide (NO) regulates gastrointestinal motility by relaxing smooth muscle. Pharmacological cAMP induction also relaxes gastrointestinal smooth muscle, but it is uncertain whether cAMP augments or suppresses enteric NO signalling. In other organ systems, cAMP can increase neuronal NO production by stimulating protein kinase A (PKA) to phosphorylate neuronal NOS (nNOS) Serine-1412 (S1412). We hypothesized that cAMP also increases nNOS S1412 phosphorylation by PKA in enteric neurons to augment nitrergic relaxation of mouse ileum. EXPERIMENTAL APPROACH: We measured contractile force and nNOS S1412 phosphorylation in ileal rings suspended in an organ bath. We used forskolin to induce cAMP-dependent relaxation of wild type, nNOSS1412A knock-in and nNOSα-null ileal rings in the presence or absence of PKA, protein kinase B (Akt) and NOS inhibitors. KEY RESULTS: Forskolin stimulated phosphorylation of nNOS S1412 in mouse ileum. Forskolin relaxed nNOSα-null and nNOSS1412A ileal rings less than wild-type ileal rings. PKA inhibition blocked forskolin-induced nNOS phosphorylation and attenuated relaxation of wild type but not nNOSS1412A ileum. Akt inhibition did not alter nNOS phosphorylation with forskolin but did attenuate relaxation of wild type and nNOSS1412A . NOS inhibition with L-NAME eliminated the effects of PKA and Akt inhibitors on relaxation. CONCLUSION AND IMPLICATIONS: PKA phosphorylation of nNOS S1412 augments forskolin-induced nitrergic ileal relaxation. The relationship between cAMP/PKA and NO is therefore synergistic in enteric nitrergic neurons. Because NO regulates gut motility, selective modulation of enteric neuronal cAMP synthesis may be useful for the treatment of gastrointestinal motility disorders.

Prevention and Management of Severe Obstetric Anal Sphincter Injuries (OASIs): a National Survey of Nurse- Midwives.

INTRODUCTION AND HYPOTHESIS: There are no data on midwives' knowledge and management of obstetric anal sphincter injuries (OASIs) in the USA. We performed a cross-sectional national survey characterizing OASI practice by certified nurse midwives (CNMs), hypothesizing that few midwives personally repair OASIs and that there are gaps in CNM OASI training/education. METHODS: We emailed a REDCap internet-based survey to 6909 American College of Nurse Midwives members (ACNM). We analyzed responses from active clinicians performing at least one delivery per month, asking about OASI risks, prevention, repair, and management. We summarized descriptive data then evaluated OASI knowledge by patient and provider characteristics. RESULTS: We received 1070 (15.5%) completed surveys, and 832 (77.8%) met the inclusion/exclusion criteria. Participants were similar to ACNM membership. Respondents most frequently identified prior OASI (87%) and nutrition (71%) as antepartum OASI risk factors and, less frequently, nulliparity (36%) and race (22%). Identified intrapartum risks included forceps delivery (94%) and midline episiotomy (88%). When obstetric laceration is suspected, 13.6% of respondents perform a rectal examination routinely. Only 15% of participants personally perform OASI repair. Overall, participants matched 64% of evidence-based answers. OASI education/training courses were attended by 30% of respondents, and 44% knew of OASI protocols within their group/institution. Of all factors evaluated, the percent of evidence-based responses was only different for respondent education/CME and protocols. CONCLUSIONS: Quality initiatives regarding OASI prevention and management may improve care. Our data suggest OASI training for midwives may improve delivery care in the US. Further studies of other obstetric providers are needed.

Outcomes of trial of labor after cesarean birth by provider type in low-risk women.

BACKGROUND: One approach to decreasing the cesarean birth rate in the United States is to increase the availability of birth attendants, including certified nurse-midwives (CNMs), who offer trial of labor after cesarean (TOLAC). We examined associations between provider type and mode of birth for women attempting vaginal birth after cesarean (VBAC). METHODS: We performed a retrospective cohort study at a United States academic medical center using prospectively-collected data (2005-2012). We included healthy women with term singleton vertex pregnancies after one or two prior cesareans who were managed by obstetricians or CNMs. We assessed unplanned cesarean birth by provider type using univariate and logistic regression and examined labor interventions and predicted VBAC success. RESULTS: Overall VBAC success was 88% for 502 included patients. Unplanned cesarean rates were similar by provider type. Black race, no prior VBAC, recurring clinical indication for cesarean, labor augmentation/induction, and any Pitocin use were associated with increased unplanned cesarean. Higher parity and early-term gestational age at delivery were associated with decreased unplanned cesarean. Postpartum hemorrhage and composite maternal morbidity were increased with unplanned cesarean, but there was no difference in neonatal outcome by mode of delivery or provider type. Obstetricians had slightly higher composite adverse maternal outcomes. Nomogram-predicted VBAC success but not provider type was associated with unplanned cesarean. CONCLUSIONS: Unplanned cesarean was similar for patients attempting labor after cesarean managed by midwives or obstetricians. Increasing the number of CNMs who manage TOLAC may help decrease the high rate of cesareans.

Adiponectin links maternal metabolism to uterine contractility.

Adiponectin is secreted by adipose tissue and promotes insulin sensitivity. Low circulating adiponectin is associated with increased risk for preterm labor, but the influence of adiponectin on uterine myometrial physiology is unknown. We hypothesized that adiponectin receptors (AdipoRs) decrease myometrial contractility via AMPK to promote uterine quiescence in pregnancy. Using quantitative RT-PCR, we found that nonpregnant or pregnant human and mouse myometrium express AdipoR1 and AdipoR2 mRNAs. We confirmed AdipoR2 protein expression in human and mouse myometrium, with increased abundance in late mouse pregnancy. Both recombinant adiponectin and a pharmacologic AdipoR agonist, AdipoRon, potently inhibited uterine myometrial strip contractions in physiologic organ bath. The relaxation was independent of contractile stimulus (oxytocin, KCl, U46619). AdipoR agonists increased AMPK phosphorylation in pregnant mouse myometrium, and the direct AMPK activator A769662 also relaxed myometrial strips. However, the AMPK inhibitor dorsomorphin (compound C) blocked AMPK phosphorylation but did not abolish relaxation with either AdipoRon or A769662. In summary, adiponectin inhibits myometrial contractility consistent with the possibility that it is a previously unrecognized link between maternal metabolism and pregnancy maintenance. We also identify a separate role for AMPK regulating myometrial contractions that may influence labor onset.-Vyas, V., Guerra, D. D., Bok, R., Powell, T., Jansson, T., Hurt, K. J. Adiponectin links maternal metabolism to uterine contractility.

Akt phosphorylation of neuronal nitric oxide synthase regulates gastrointestinal motility in mouse ileum.

Nitric oxide (NO) is a major inhibitory neurotransmitter that mediates nonadrenergic noncholinergic (NANC) signaling. Neuronal NO synthase (nNOS) is activated by Ca2+/calmodulin to produce NO, which causes smooth muscle relaxation to regulate physiologic tone. nNOS serine1412 (S1412) phosphorylation may reduce the activating Ca2+ requirement and sustain NO production. We developed and characterized a nonphosphorylatable nNOSS1412A knock-in mouse and evaluated its enteric neurotransmission and gastrointestinal (GI) motility to understand the physiologic significance of nNOS S1412 phosphorylation. Electrical field stimulation (EFS) of wild-type (WT) mouse ileum induced nNOS S1412 phosphorylation that was blocked by tetrodotoxin and by inhibitors of the protein kinase Akt but not by PKA inhibitors. Low-frequency depolarization increased nNOS S1412 phosphorylation and relaxed WT ileum but only partially relaxed nNOSS1412A ileum. At higher frequencies, nNOS S1412 had no effect. nNOSS1412A ileum expressed less phosphodiesterase-5 and was more sensitive to relaxation by exogenous NO. Under non-NANC conditions, peristalsis and segmentation were faster in the nNOSS1412A ileum. Together these findings show that neuronal depolarization stimulates enteric nNOS phosphorylation by Akt to promote normal GI motility. Thus, phosphorylation of nNOS S1412 is a significant regulatory mechanism for nitrergic neurotransmission in the gut.

Gasotransmitters in pregnancy: from conception to uterine involution.

Gasotransmitters are endogenous small gaseous messengers exemplified by nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S or sulfide). Gasotransmitters are implicated in myriad physiologic functions including many aspects of reproduction. Our objective was to comprehensively review basic mechanisms and functions of gasotransmitters during pregnancy from conception to uterine involution and highlight future research opportunities. We searched PubMed and Web of Science databases using combinations of keywords nitric oxide, carbon monoxide, sulfide, placenta, uterus, labor, and pregnancy. We included English language publications on human and animal studies from any date through August 2018 and retained basic and translational articles with relevant original findings. All gasotransmitters activate cGMP signaling. NO and sulfide also covalently modify target protein cysteines. Protein kinases and ion channels transduce gasotransmitter signals, and co-expressed gasotransmitters can be synergistic or antagonistic depending on cell type. Gasotransmitters influence tubal transit, placentation, cervical remodeling, and myometrial contractility. NO, CO, and sulfide dilate resistance vessels, suppress inflammation, and relax myometrium to promote uterine quiescence and normal placentation. Cervical remodeling and rupture of fetal membranes coincide with enhanced oxidation and altered gasotransmitter metabolism. Mechanisms mediating cellular and organismal changes in pregnancy due to gasotransmitters are largely unknown. Altered gasotransmitter signaling has been reported for preeclampsia, intrauterine growth restriction, premature rupture of membranes, and preterm labor. However, in most cases specific molecular changes are not yet characterized. Nonclassical signaling pathways and the crosstalk among gasotransmitters are emerging investigation topics.