Oxytocin: physiology, pharmacology, and clinical application for labor management.

Oxytocin is a peptide hormone that plays a key role in regulating the female reproductive system, including during labor and lactation. It is produced primarily in the hypothalamus and secreted by the posterior pituitary gland. Oxytocin can also be administered as a medication to initiate or augment uterine contractions. To study the effectiveness and safety of oxytocin, previous studies have randomized patients to low- and high-dose oxytocin infusion protocols either alone or as part of an active management of labor strategy along with other interventions. These randomized trials demonstrated that active management of labor and high-dose oxytocin regimens can shorten the length of labor and reduce the incidence of clinical chorioamnionitis. The safety of high-dose oxytocin regimens is also supported by no associated differences in fetal heart rate abnormalities, postpartum hemorrhage, low Apgar scores, neonatal intensive care unit admissions, and umbilical artery acidemia. Most studies reported no differences in the cesarean delivery rates with active management of labor or high-dose oxytocin regimens, thereby further validating its safety. Oxytocin does not have a predictable dose response, thus the pharmacologic effects and the amplitude and frequency of uterine contractions are used as physiological parameters for oxytocin infusion titration to achieve adequate contractions at appropriate intervals. Used in error, oxytocin can cause patient harm, highlighting the importance of precise administration using infusion pumps, institutional safety checklists, and trained nursing staff to closely monitor uterine activity and fetal heart rate changes. In this review, we summarize the physiology, pharmacology, infusion regimens, and associated risks of oxytocin.

Telehealth Strategies for the Delivery of Maternal Health Care : A Rapid Review.

BACKGROUND: Telehealth strategies to supplement or replace in-person maternity care may affect maternal health outcomes. PURPOSE: To conduct a rapid review of the effectiveness and harms of telehealth strategies for maternal health care given the recent expansion of telehealth arising from the COVID-19 pandemic, and to produce an evidence map. DATA SOURCES: Systematic searches of MEDLINE, the Cochrane Library, CINAHL, Embase, and Scopus for English-language studies (January 2015 to April 2022). STUDY SELECTION: Randomized controlled trials (RCTs) and observational studies of maternal care telehealth strategies versus usual care. DATA EXTRACTION: Dual data extraction and risk-of-bias assessment of studies, with disagreements resolved through consensus. DATA SYNTHESIS: 28 RCTs and 14 observational studies (n = 44 894) were included. Maternal telehealth interventions supplemented in-person care for most studies of mental health and diabetes during pregnancy, primarily resulting in similar, and sometimes better, clinical and patient-reported outcomes versus usual care. Supplementing in-person mental health care with phone- or web-based platforms or mobile applications resulted in similar or better mental health outcomes versus in-person care. A reduced-visit prenatal care schedule using telehealth to replace in-person general maternity care for low-risk pregnancies resulted in similar clinical outcomes and higher patient satisfaction versus usual care. Overall, telehealth strategies were heterogeneous and resulted in similar obstetric and patient satisfaction outcomes. Few studies addressed disparities, health equity, or harms. LIMITATIONS: Interventions varied, and evidence was inadequate for some clinical outcomes. CONCLUSION: Replacing or supplementing in-person maternal care with telehealth generally results in similar, and sometimes better, clinical outcomes and patient satisfaction compared with in-person care. The effect on access to care, health equity, and harms is unclear. PRIMARY FUNDING SOURCE: Patient-Centered Outcomes Research Institute. (PROSPERO: CRD42021276347).

Outpatient Cervical Ripening: A Systematic Review and Meta-analysis.

OBJECTIVE: To assess the comparative effectiveness and potential harms of cervical ripening in the outpatient compared with the inpatient setting, or different methods of ripening in the outpatient setting alone. DATA SOURCES: Searches for articles in English included MEDLINE, EMBASE, CINAHL, Cochrane Library, ClinicalTrials.gov, and reference lists (up to August 2020). METHODS OF STUDY SELECTION: Using predefined criteria and DistillerSR software, 10,853 citations were dual-reviewed for randomized controlled trials (RCTs) and cohort studies of outpatient cervical ripening using prostaglandins and mechanical methods in pregnant women at or beyond 37 weeks of gestation. TABULATION, INTEGRATION, AND RESULTS: Using prespecified criteria, study data abstraction and risk of bias assessment were conducted by two reviewers, random-effects meta-analyses were conducted and strength of evidence was assessed. We included 30 RCTs and 10 cohort studies (N=9,618) most generalizable to women aged 25-30 years with low-risk pregnancies. All findings were low or insufficient strength of evidence and not statistically significant. Incidence of cesarean delivery was not different for any comparison of inpatient and outpatient settings, or comparisons of different methods in the outpatient setting (most evidence available for single-balloon catheters and dinoprostone). Harms were inconsistently reported or inadequately defined. Differences were not found for neonatal infection (eg, sepsis) with outpatient compared with inpatient dinoprostone, birth trauma (eg, cephalohematoma) with outpatient compared with inpatient single-balloon catheter, shoulder dystocia with outpatient dinoprostone compared with placebo, maternal infection (eg, chorioamnionitis) with outpatient compared with inpatient single-balloon catheters or outpatient prostaglandins compared with placebo, and postpartum hemorrhage with outpatient catheter compared with inpatient dinoprostone. Evidence on misoprostol, hygroscopic dilators, and other outcomes (eg, perinatal mortality and time to vaginal birth) was insufficient. CONCLUSION: In women with low-risk pregnancies, outpatient cervical ripening with dinoprostone or single-balloon catheters did not increase cesarean deliveries. Although there were no clear differences in harms when comparing outpatient with inpatient cervical ripening, the certainty of evidence is low or insufficient to draw definitive conclusions. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42020167406.

Antenatal Corticosteroids for Pregnant Women at High Risk of Preterm Delivery with COVID-19 Infection: A Decision Analysis.

OBJECTIVE: Antenatal corticosteroids given prior to preterm deliveries reduce the risk of adverse neonatal outcomes. However, steroid administration in the setting of a viral respiratory infection can worsen maternal outcomes. Therefore, the decision to administer corticosteroids must balance the neonatal benefits with the potential harm to the mother if she is infected with the novel coronavirus disease 2019 (COVID-19). This study aimed to determine the gestational ages for which administering antenatal corticosteroids to women at high risk of preterm labor with concurrent COVID-19 infection results in improved combined maternal and infant outcomes. STUDY DESIGN: A decision-analytic model using TreeAge (2020) software was constructed for a theoretical cohort of hospitalized women with COVID-19 in the United States. All model inputs were derived from the literature. Outcomes included maternal intensive care unit (ICU) admission and death, along with infant outcomes of death, respiratory distress syndrome, intraventricular hemorrhage, and neurodevelopmental delay. Quality-adjusted life years (QALYs) were assessed from the maternal and infant perspectives. Sensitivity analyses were performed to determine if the results were robust over a range of assumptions. RESULTS: In our theoretical cohort of 10,000 women delivering between 24 and 33 weeks of gestation with COVID-19, corticosteroid administration resulted in 2,200 women admitted to the ICU and 110 maternal deaths. No antenatal corticosteroid use resulted in 1,500 ICU admissions and 75 maternal deaths. Overall, we found that corticosteroid administration resulted in higher combined QALYs up to 31 weeks of gestation in all hospitalized patients, and up to 29 weeks of gestation in ICU patients. CONCLUSION: Administration of antenatal corticosteroids at less than 32 weeks of gestation for hospitalized patients and less than 30 weeks of gestation for patients admitted to the ICU resulted in higher combined maternal and infant outcomes compared with expectant management for women at high risk of preterm birth with COVID-19 infection. These results can guide clinicians in their counseling and management of these pregnant women. KEY POINTS: · Antenatal steroids reduce adverse neonatal outcomes.. · Steroids worsen maternal outcomes in COVID-19.. · Steroids given < 32 weeks result in improved outcomes..

Aplastic anemia during pregnancy: a review of obstetric and anesthetic considerations.

Aplastic anemia is a hematologic condition occasionally presenting during pregnancy. This pathological process is associated with significant maternal and neonatal morbidity and mortality. Obstetric and anesthetic management is challenging, and treatment requires a coordinated effort by an interdisciplinary team, in order to provide safe care to these patients. In this review, we describe the current state of the literature as it applies to the complexity of aplastic anemia in pregnancy, focusing on pathophysiologic aspects of the disease in pregnancy, as well as relevant obstetric and anesthetic considerations necessary to treat this challenging problem. A multidisciplinary-team approach to the management of aplastic anemia in pregnancy is necessary to coordinate prenatal care, optimize maternofetal outcomes, and plan peripartum interventions. Conservative transfusion management is critical to prevent alloimmunization. Although a safe threshold-platelet count for neuraxial anesthesia has not been established, selection of anesthetic technique must be evaluated on a case-to-case basis.

Body Mass Index and the Spontaneous Onset of Parturition.

OBJECTIVE: To investigate the relationship between body mass index (BMI) and the onset of parturition throughout gestation. METHODS: This was a secondary analysis of the Maternal-Fetal Medicine Units Network Preterm Prediction Study. Time-to-spontaneous-birth-event (ie, "survival") methods were used to study the association of BMI with the timing of spontaneous onset of labor throughout gestation with indicated births censored at delivery. A Kaplan-Meier estimate of the probability of spontaneous labor was compared with a log rank test across five categories of BMI (kg/m): underweight (less than 18.5), normal weight (18.5-24.99), preobese (25-29.99), obese I (30-34.99), and obese II+ (35 or greater). A proportional hazards model was estimated to compare time to spontaneous onset of labor adjusted for multiple variables known to be associated with the onset of labor. RESULTS: Normal-weight women (n=1,054) had a median delivery gestational age of 39 3/7 weeks. Obese II+ women (n=178) had a median delivery gestational age 5 days later than normal-weight women (P<.001). Delivery gestational age of preobese (n=866) and obese I (n=548) women was not significantly different from normal-weight women. Underweight women (n=41) had a median delivery gestational age 5 days earlier than normal-weight women (P<.001). Compared with women with normal BMIs, obese II+ women were significantly less likely and underweight women significantly more likely to enter spontaneous labor at all gestational ages. In the multivariable model, BMI was significantly associated with spontaneous onset of labor throughout pregnancy (BMI [five-unit] adjusted hazard ratio 0.874, 0.829-0.921). CONCLUSION: Body mass index is significantly associated with the likelihood of the spontaneous onset of labor at all gestational ages with gestational age at the time of delivery and BMI being inversely related. This novel observation unifies previous reports focusing on the association of overweight and underweight BMIs and preterm and postterm birth and may inform discussions surrounding elective induction of labor at term.