Sheri Jenkins

Tocolytic Therapy for Acute Preterm Labor

The pathophysiology leading to preterm labor is not well understood and often multifactorial; initiating factors include intrauterine infection, inflammation, ischemia, overdistension, and hemorrhage. Given these different potential causes, directing therapy for preterm labor has been difficult and suboptimal. To date, no single drug has been identified as successful in treating all of the underlying mechanisms leading to preterm labor. In addition, the methodology of many of the tocolytic studies is limited by lack of sufficient patient numbers, lack of comparison with a placebo, and inconsistent use of glucocorticoids. The limitations in these individual studies make it difficult to evaluate the efficacy of a single tocolytic by meta-analysis. Despite these limitations, the goals for tocolysis for preterm labor are clear: To complete a course of glucocorticoids and secure the appropriate level of neonatal care for the fetus in the event of preterm delivery. The literature demonstrates that many tocolytic agents inhibit uterine contractility. The decision as to which tocolytic agent should be used as first-line therapy for a patient is based on multiple factors, including gestational age, the patient’s medical history, common and severe side effects, and a patient’s response to therapy. In a patient at less than 32 weeks gestation, indomethacin may be a reasonable first choice based on its efficacy, ease of administration, and minimal side effects. Concurrent administration of magnesium for neuroprotection may be given. At 32 to 34 weeks, nifedipine may be a reasonable first choice because it does not carry the fetal risks of indomethacin at these later gestational ages, is easy to administer, and has limited side effects relative to beta-mimetics. In an effort to review a commonly faced obstetrical complication, this article has provided a summary of the most commonly used tocolytics, their mechanisms of action, side effects, and clinical data regarding their efficacy.

The Performance of First-Trimester Anatomy Scan: A Decision Analysis.

Introduction First-trimester ultrasound (US) for anatomy assessment may improve anomaly detection, but it may also increase overall US utilization. We sought to assess the utility of first-trimester US for evaluation of fetal anatomy. Materials and Methods A decision analytic model was created to compare first- plus second-trimester anatomy scans to second-trimester scan alone in four populations: general, normal weight women, obese women, and diabetics. Probability estimates were obtained from the literature. Outcomes considered were number of: major structural anomalies detected, US performed, and false-positive US. Multivariable sensitivity analyses were performed to evaluate the consistency of the model with varying assumptions. Results A strategy of first- plus second-trimester US detected the highest number of anomalies but required more US examinations per anomaly detected. The addition of a first-trimester anatomy US was associated with a small increase in the false-positive US (< 10/10,000). In populations with higher anomaly prevalence and lower second-trimester US sensitivity (i.e., diabetes, obesity), the number of additional US performed per anomaly detected with the first-trimester US was < 60. Discussion In high-risk populations, a first-trimester US in addition to a second-trimester US may be a beneficial approach to detecting anomalies.

The Utility of Repeat Midtrimester Anatomy Ultrasound for Anomaly Detection

Introduction Although guidelines recommend repeat ultrasound in the setting of an incomplete fetal anatomic survey, the clinical utility of this practice has not been established. As such, we aimed to assess the yield of repeat ultrasound for anomaly detection following an incomplete survey. Materials and Methods This is a retrospective cohort study of all singletons who underwent a midtrimester anatomic ultrasound at University of Alabama at Birmingham (UAB) from 2006 to 2014. Patients with an incomplete ultrasound underwent repeat examinations until completion. The population was divided into cohorts FIRST, SECOND, and THIRD, corresponding to the ultrasound at which the exam was deemed complete. Each detected anomaly was tallied. The number of ultrasounds needed to detect an anomaly was then assessed per group. Results Of 15,768 ultrasounds performed on 13,740 patients, 11,828 exams were completed on first attempt; 1,796 patients required a second, while 116 patients required a third scan or more. We detected 324 anomalies; 93.8% in FIRST, 5.9% in SECOND, and 0.3% in THIRD. The number of scans needed to detect an anomaly was 39, 189, and 348 for FIRST, SECOND, and THIRD, respectively. Conclusion Over 90% of anomalies are detected on the initial fetal anatomic survey. The incremental diagnostic yield then decreases, requiring appreciably more repeat scans to detect one anomaly.