Clinical Impact of a Restrictive Labor Induction Approval Process.

BACKGROUND/AIMS: The aim of this study was to evaluate the impact of a restrictive labor induction approval process on induction and primary cesarean delivery rates. METHODS: A retrospective cohort study was conducted at a tertiary care academic center from 2006 through 2012. The cohort of deliveries before (pre-intervention) and after (post-intervention) the process included term, singleton pregnancies with no contraindication to vaginal delivery. The primary outcome was induction of labor rates, subgrouped on the basis of whether it was medically or nonmedically indicated. Secondary outcomes included the primary cesarean rate and other maternal and neonatal outcomes. RESULTS: Of 13,753 deliveries, 6,746 met study inclusion criteria. There was a significant decrease in induction rates comparing the pre- and post-intervention periods (21.0 vs. 18.5%, p = 0.01). Nonmedically indicated induction rates also decreased significantly (2.9 vs. 0.6%, p < 0.001). No difference was observed in medically indicated induction (18.1 vs. 17.9%, p = 0.84), the primary cesarean rate (14.4 vs. 15.8%, p = 0.12), or any of the measured neonatal outcomes (p > 0.05). CONCLUSIONS: Implementation of a labor induction approval process was associated with a significant reduction in overall and non-indicated induction rates but did not affect the primary cesarean rate or neonatal outcomes.

Transplacental Passage of Acetaminophen in Term Pregnancy.

Objective The objective of this study was to determine the maternal and fetal pharmacokinetic (PK) profiles of acetaminophen after administration of a therapeutic oral dose. Study Design After obtaining Institutional Review Board approval and their written informed consent, pregnant women were given a single oral dose (1,000 mg) of acetaminophen upon admission for scheduled cesarean delivery. Maternal venous blood and fetal cord blood were obtained at the time of delivery and acetaminophen levels were measured using gas chromatography-mass spectroscopy. PK parameters were calculated by noncompartmental analysis. Nonparametric correlation of maternal/fetal acetaminophen levels and PK curves were calculated. Results In this study, 34 subjects were enrolled (median, 32 years; range, 25-39 years). The median maternal weight was 82 kg (range, 62-100 kg). All but two subjects were delivered beyond 39 weeks' gestation. The median newborn birth weight was 3,590 g (interquartile range, 3,403-3,848 g). Noncompartmental analysis described similar PK parameters in the maternal (T1/2, 84 minutes; apparent clearance [Cl/F], 28.8 L/h; apparent volume of distribution [Vd/F], 57.5 L) and fetal compartments (T1/2, 82 minutes; Cl/F, 31.2 L/h; Vd/F, 61.2 L). Paired maternal/fetal acetaminophen levels were highly correlated (p < 0.0001). Conclusion Fetal acetaminophen PKs in the fetus parallels that in the mother suggesting that placental transfer is flow limited. Maternal acetaminophen levels can be used as a surrogate for fetal exposure.

Applying to subspecialty fellowship: clarifying the confusion and conflicts!

Of graduating obstetrics and gynecology residents, 40% apply for fellowship training and this percentage is likely to increase. The fellowship interview process creates a substantial financial burden on candidates as well as significant challenges in scheduling the multiple interviews for residents, residency programs, and fellowship programs. Coverage with relatively short lead time is needed for some resident rotations, multiple residents may request time off during overlapping time periods, and applicants may not be able to interview based on conflicting interview dates or the inability to find coverage from other residents for their clinical responsibilities. To address these issues, we propose that each subspecialty fellowship within obstetrics and gynecology be allocated a specified and limited time period to schedule their interviews with minimal overlap between subspecialties. Furthermore, programs in close geographic areas should attempt to coordinate their interview dates. This will allow residents to plan their residency rotation schedules far in advance to minimize the impact on rotations that are less amenable to time away from their associated clinical duties, and decrease the numbers of residents needing time off for interviews during any one time period. In addition, a series of formal discussions should take place between subspecialties related to these issues as well as within subspecialties to facilitate coordination.

Antepartum nonobstetrical surgery at ≥23 weeks' gestation and risk for preterm delivery.

OBJECTIVE: We sought to describe the influence of antepartum nonobstetrical surgical procedures performed at viable fetal gestational ages (GAs) on incidence of preterm delivery. STUDY DESIGN: This was a retrospective case series of patients requiring nonobstetrical surgery at ≥23 weeks' gestation at the Mayo Clinic during the interval 1992 through 2014. Data were abstracted for maternal demographic variables, operative procedure, anesthetic type, whether intraoperative fetal monitoring was employed, and both GA and method of delivery. RESULTS: In all, 111 patients underwent 121 operative procedures at a mean GA of 29.2 weeks (range, 23-37 weeks). The majority of procedures were completed under general anesthesia (88/121, 73%), with intraoperative fetal monitoring performed in 14 cases (14/121, 12%); fetal loss occurred during a single unmonitored procedure. Outcome data were available for the majority of patients (86/111, 78%) with preterm delivery occurring in 41% (35/86) at a mean GA of 36.9 weeks (range, 25-41 weeks). Mean interval from procedure to delivery was 7.7 weeks, with 9 patients (9/86, 10%) delivering within 1 week of surgery. Neither procedures requiring entry into the abdominal cavity (P = .65) nor GA at time of procedure (P = 1.0) statistically influenced the risk of preterm delivery. CONCLUSION: Nonobstetrical surgical procedures performed at or beyond fetal viability increased the incidence of preterm delivery regardless of surgical site or timing of procedure, however the risk of intraoperative or immediate postoperative obstetrical complications was relatively low.

Challenging the 4- to 5-minute rule: from perimortem cesarean to resuscitative hysterotomy.

Although perimortem delivery has been recorded in the medical literature for millennia, the procedural intent has evolved to the current fetocentric approach, predicating timing of delivery following maternal cardiopulmonary arrest to optimize neonatal outcome. We suggest a call to action to reinforce the concept that if the uterus is palpable at or above the umbilicus, preparations for delivery should be made simultaneous with initiation of maternal resuscitative efforts; if maternal condition is not rapidly reversible, hysterotomy with delivery should be performed regardless of fetal viability or elapsed time since arrest. Cognizant of the difficulty in determining precise timing of arrest in clinical practice, if fetal status is already compromised further delay while attempting to assess fetal heart rate, locating optimal surgical equipment, or transporting to an operating room will result in unnecessary worsening of both maternal and fetal condition. Even if intrauterine demise has already occurred, maternal resuscitative efforts will typically be markedly improved following delivery with uterine decompression. Consequently we suggest that perimortem cesarean delivery be renamed "resuscitative hysterotomy" to reflect the mutual optimization of resuscitation efforts that would potentially provide earlier and more substantial benefit to both mother and baby.

Dexmedetomidine and Mannitol for Awake Craniotomy in a Pregnant Patient.

We describe the use of dexmedetomidine for an awake neurosurgical procedure in a pregnant patient and quantify the effect of mannitol on intrauterine volume. A 27-year-old woman underwent a craniotomy, with intraprocedural motor and speech mapping, at 20 weeks of gestation. Sedation was maintained with dexmedetomidine. Mannitol at 0.25 g/kg IV was administered to control brain volume during surgery. Internal uterine volume was estimated at 1092 cm before surgery and decreased to 770 and 953 cm at 9 and 48 hours, respectively, after baseline assessment. No adverse maternal or fetal effects were noted during the intraoperative period or up to 48 hours postoperatively.

Reduced syncytin-1 expression in choriocarcinoma BeWo cells activates the calpain1-AIF-mediated apoptosis, implication for preeclampsia.

Placentas associated with preeclampsia are characterized by extensive apoptosis in trophoblast lineages. Syncytin-1 (HERVWE1) mediates the fusion of cytotrophoblasts to form syncytiotrophoblasts, which assume the placental barrier, fetal-maternal exchange and endocrine functions. While decreased syncytin-1 expression has been observed in preeclamptic placentas, it is not clear if this alteration is involved in trophoblast apoptosis. In the current study, we found that siRNA-mediated knockdown of syncytin-1 led to apoptosis in choriocarcinoma BeWo, a cell line of trophoblastic origin. Characterization of the apoptotic pathways indicated that this effect does not rely on the activation of caspases. Rather, decreased syncytin-1 levels activated the apoptosis inducing factor (AIF) apoptotic pathway by inducing the expression, cleavage, and nuclear translocation of AIF. Moreover, calpain1, the cysteine protease capable of cleaving AIF, was upregulated by syncytin-1 knockdown. Furthermore, treatment with calpain1 inhibitor MDL28170 effectively reversed AIF cleavage, AIF nuclear translocation, and cell apoptosis triggered by syncytin-1 downregulation, verifying the specific action of calpain1-AIF pathway in trophoblast apoptosis. We confirmed that preeclamptic placentas express lower levels of syncytin-1 than normal placentas, and observed an inverse correlation between syncytin-1 and AIF/calpain1 mRNA levels, a result consistent with the in vitro findings. Immunohistochemistry analyses indicated decreased syncytin-1 and increased AIF and calpain1 protein levels in apoptotic cells of preeclamptic placentas. These findings have for the first time revealed that decreased levels of syncytin-1 can trigger the AIF-mediated apoptosis pathway in BeWo cells. This novel mechanism may contribute to the structural and functional deficiencies of syncytium frequently observed in preeclamptic placentas.

Impact of an Inexpensive Anatomy-Based Fetal Pig Simulator on Obstetric Ultrasound Training.

OBJECTIVES: The purpose of this study was to construct an inexpensive anatomy-based obstetric ultrasound task trainer and investigate whether introduction of this trainer into a hands-on obstetric ultrasound course improved course participants' ultrasound scanning skills. METHODS: The trainer was created by placing fetal pigs into preservative-filled heat-sealed polyethylene bags. Twenty-four participants in an obstetric ultrasound course at Wake Forest School of Medicine were randomized to receive hands-on scanning with pregnant women or hands-on scanning and fetal pig simulation. Biometric scans were performed before and after the course. The time to complete the scans, margin of error of biometric measurements, and number of technically adequate images per scan were compared between groups. RESULTS: Twelve participants were randomized into each group. Although a direct comparison of postcourse biometric scans demonstrated no difference between groups, participants that received simulation training showed significant improvements in the time to complete the biometric scan (P < .05) and number of technically adequate images obtained (P < .05), whereas those who did not receive simulation training did not show significant improvements. CONCLUSIONS: Addition of the fetal pig ultrasound task trainer resulted in improvements in the course participants' scanning efficiency even after very limited exposure. Incorporating the task trainer earlier and more broadly into obstetric ultrasound training may benefit trainees.

Development of an Endometrial Ablation Model in New Zealand White Rabbits.

OBJECTIVE: To develop an animal model for radiofrequency endometrial ablation (EA) and evaluate histopathologic outcomes of EA in New Zealand White (NZW) rabbits. STUDY DESIGN: A pilot study was conducted. A radiofrequency EA device was developed and a variety of EA settings were tested on euthanized NZW rabbits. An algorithm was developed to determine target EA parameters. Bilateral radiofrequency EA was performed via laparotomy using 5.2 mm, 6.1 mm, or 7.1 mm diameter x 100 mm bipolar probes on 10 live NZW rabbits. All rabbits were screened for endometrial cancer (EC). Rabbits were euthanized 3 weeks following EA, and histopathologic analysis of postablation hysterectomy specimens was performed. RESULTS: Bilateral radiofrequency EA was successful in rabbits that were candidates for the procedure, and uterine assessment was feasible in all rabbits. One case of EC was detected. Uterine anatomy was variable among rabbits. The optimal EA setting was 4.5 W/cm2 x 20 seconds, which provided consistent thermal destruction to the endometrium and inner myometrium as verified by histology. CONCLUSION: Use of a radiofrequency EA algorithm tailored to individual NZW rabbits produces consistent thermal destruction of the endometrium and inner myometrium. This animal model can be used to study the long-term consequences of EA and the association with EC.

Mass spectrometry as a novel method for detection of podocyturia in pre-eclampsia.

BACKGROUND: Podocyturia, i.e. urinary loss of viable podocytes, may serve as a diagnostic tool for pre-eclampsia and as a marker of active renal disease. The current method to detect podocyturia is technically complex, lengthy and requires a high level of expertise for interpretation. The aim of this study was to develop a new technique for the identification of urinary podocytes, based on the detection of podocyte-specific tryptic peptides by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), which will provide an operator-independent and highly reproducible method. METHODS AND RESULTS: The diagnosis of pre-eclampsia was confirmed in the presence of hypertension (>140/90 mmHg) and proteinuria >0.3 g/24 h urine. The diagnosis of HELLP was confirmed based on the accepted clinical criteria of hemolysis, elevated liver enzymes and low platelet count. Random urine samples within 24 h prior to delivery were collected and centrifuged. One half of the sediment was cultured for 24 h to select for viable cells and then stained with a podocin antibody, followed by a secondary fluorescein isothiocyanate-labeled antibody to identify podocytes. The second half of the pellet was solubilized, digested and analyzed by LC-MS/MS using an internal standard. We have recruited 13 patients with pre-eclampsia and 6 patients with pre-eclampsia/HELLP syndrome. The presence of podocytes was confirmed in all patients by the podocyte culture method. In the respective samples, the presence of a podocin-specific tryptic peptide was confirmed with LC-MS/MS technology. CONCLUSION: The LC-MS/MS method is a reliable technology for the identification of urinary podocytes, based on the presence of podocyte-specific proteins in the urine.

Low-Cost Task Trainer for In Utero Fetal Stent Placement.

INTRODUCTION: Some fetal procedures such as intrauterine fetal stent placement remain rare, and simulation is needed to help learners and specialists in attaining and maintaining technical competence. We sought to design and assess a low-cost, easily assembled yet clinically relevant task trainer for fetal stent placement. METHOD: The simulator was constructed using 2 quart-sized freezer bags filled with ultrasound gel and sealed with clear packing tape. The bags were stacked vertically in a transparent plastic container with ultrasound gel applied between the bags when ultrasound was used. This task trainer was used to deploy in utero stents with or without the use of ultrasound. It has been used at the annual meeting of the Society for Maternal-Fetal Medicine since 2015, the annual meeting of the International Society of Ultrasound in Obstetrics and Gynecology in 2015 and 2016, and at regional Maternal-Fetal Medicine Fellow simulation workshops since 2016. Participants were asked to complete a 5-point Likert scale survey regarding the model's realism and usefulness in training. RESULTS: One hundred thirty-three course participants evaluated the task trainer. The median rating for realism of the ultrasound images, haptic feel of stent deployment, and usefulness in training was 5 (interquartile range, 4-5). Seven physicians participated in the timed assessment of model assembly, stent deployment, and model reassembly. The average times required for the freezer bag task trainer were 2.3 minutes (2.20-2.35), 1.0 minutes (0.70-1.93), and 0.1 minutes (0.08-0.10), respectively. For the porcine tissue-based model tested in parallel, the average times were 6.0 minutes (5.00-7.06), 3.7 minutes (3.63-3.75), and 3.3 minutes (3.00-3.70), respectively. CONCLUSIONS: This low-cost simulator was rated highly when used to practice in utero stent deployment and allows for numerous repetitions in each training session. It could be a valuable tool in training novice providers and allow more experienced providers to maintain competence in this low-volume procedure.

The effects of heparin, aspirin, and maternal clinical factors on the rate of nonreportable cell-free DNA results: a retrospective cohort study.

BACKGROUND: Technological advances in the analysis of cell-free DNA in maternal serum have allowed expanded prenatal screening possibilities for fetal aneuploidies. The sensitivity and positive predictive value of the assay are partly dependent on the amount of cell-free DNA present in maternal circulation. Thus, it is important to know what fetal and maternal factors influence the level of cell-free DNA in maternal circulation. Maternal heparin use has been associated with an increase in nonreportable cell-free DNA results because of a low fetal fraction in some, but not all, previous studies. In addition, there are likely additional factors that affect cell-free DNA that remain uncharacterized. OBJECTIVE: This study aimed to determine whether heparins, low-dose aspirin, and maternal clinical factors affect the rate of nonreportable cell-free DNA testing results. STUDY DESIGN: A retrospective cohort study was conducted using pregnant people receiving cell-free fetal DNA testing from January 1, 2014, to June 30, 2018. Data were collected on patient demographics, medical comorbidities, medication use, and cell-free DNA test results. Univariate and multivariate analyses were performed to determine which factors were independently associated with the rate of nonreportable results. RESULTS: From an original sample of 1117 pregnant people, 743 met the inclusion criteria. Maternal weight (odds ratio, 1.02), heparin use (odds ratio, 12.06), aspirin use (odds ratio, 4.70), chronic hypertension (odds ratio, 5.26), pregestational diabetes mellitus (odds ratio, 2.46), and autoimmune disease (odds ratio, 3.59) were significantly associated with an increased rate of nonreportable results in the univariate analysis. Moreover, the association was present for maternal weight (odds ratio, 1.02), heparin use (odds ratio, 21.87),and aspirin use (odds ratio, 2.85) in the multivariate analysis. CONCLUSION: The previously seen association between maternal heparin use and an increase in nonreportable cell-free DNA results was confirmed. Furthermore, there seems to be an increase in nonreportable results in pregnant people taking low-dose aspirin. Providers should consider the effect of these medications when counseling patients on prenatal genetic screening options.

Transabdominal and transcervical chorionic villus sampling models to teach maternal-fetal medicine fellows.

OBJECTIVE: Many fellowship programs in maternal-fetal medicine (MFM) lack sufficient exposure and training in chorionic villus sampling (CVS). We describe a novel training model of transabdominal and transcervical CVS. METHODS: A porcine heart simulated a 12-week human uterus with a cervical canal created at the apex of the heart. A piglet was placed within a water-filled condom, which was placed inside the "uterus." A second water-filled condom simulated a maternal bladder. Fresh human placenta was placed between the condom and uterine wall. A zipper-sealed freezer bag with ultrasonic gel simulated an abdominal wall. Transabdominal ultrasound was utilized with this model to perform CVS. RESULTS: The design involved four MFM specialists and three fellows. Twenty-three faculty MFM specialists and eight MFM fellows endorsed the fidelity of both models. One hundred percent of attendees of a procedural workshop agreed that these models could be used to teach proper technique to fellows and faculty. CONCLUSION: We report a novel training model for transabdominal and transcervical CVS to teach proper technique in a nonclinical setting.

Hands-on Simulation Workshop for Obstetric Ultrasound-Guided Invasive Procedures.

Introduction: Due to the introduction of cell-free DNA genetic testing options, the number of clinical ultrasound procedures has greatly diminished in recent years. With fewer real-life ultrasound-guided procedures being performed, it is difficult for OB/GYN and maternal-fetal medicine (MFM) trainees to achieve competency in doing them. Simulation can be utilized to address this issue and supplement a learner's real-life training. Methods: We developed a simulation workshop incorporating previously described ultrasound guidance task trainers and simulators of amniocentesis and chorionic villus sampling. The workshop had three parts: needle guidance basics, targeting task performance, and procedure-specific simulation. A form of this workshop has been held at the annual meeting of the Society for Maternal-Fetal Medicine since 2015 and as a regional course for MFM fellows since 2017. During the 2019 and 2020 courses, participants completed Likert-scale surveys evaluating the course. Results: Since the workshops began in 2015, approximately 300 people have participated. In 2019-2020, 41 MFM attending physicians, 136 MFM fellows, and three OB/GYN residents took our course and completed a postcourse survey. Participants rated the course highly and thought it was highly effective. Discussion: We created an introductory simulation workshop for obstetric ultrasound-guided invasive procedures that participants rated highly and thought was very effective. Objective clinical assessment of skill improvement after completion of this course is needed to verify its true impact. Repeated exposure to this introductory simulation and creation of more challenging workshops are needed to achieve a sustained high level of procedural skill.

Differential Expression of CB1 Cannabinoid Receptor and Cannabinoid Receptor Interacting Protein 1a in Labor.

Background: The endocannabinoid system is present in multiple organ systems and is involved in smooth muscle regulation, immune function, neuroendocrine modulation, and metabolism of tissues. Limited data are available regarding the presence and role of this system in reproductive tissues. Components of the endocannabinoid system have been identified in myometrial and placental tissues. However, no study has investigated differential expression of the endocannabinoid system in labor. Objectives: The purpose of this study was to identify and quantify two components of the endocannabinoid system, the CB1 cannabinoid receptor and cannabinoid receptor interacting protein 1a (CRIP1a) in uterine and placental tissues, and to determine if there is differential expression in tissues exposed to labor. We hypothesized that CB1 cannabinoid receptor concentration would be altered in uterine and placental tissue exposed to labor compared with tissues not exposed to labor. Study Design: Uterine and placental tissue samples were collected in nine laboring and 11 nonlaboring women undergoing cesarean delivery. CB1 cannabinoid receptor and CRIP1a presence and quantification were evaluated using western blot, immunohistochemistry, and real-time quantitative polymerase chain reaction. Statistical comparisons of laboring and nonlaboring subjects were made for uterine and placental tissue using a Mann-Whitney test. Results: Immunohistochemistry demonstrated positive staining for CB1 cannabinoid receptors and CRIP1a in uterine tissue. The protein abundance of CB1 cannabinoid receptor in uterine tissue was significantly lower in tissues exposed to labor (p=0.01). The protein abundance of CRIP1a was lower in uterine tissue exposed to labor but did not reach statistical significance (p=0.06). mRNA expression of CB1 cannabinoid receptor (p=0.20) and CRIP1a (p=0.63) did not differ in labored compared with nonlabored uterine tissues. Conclusions: Our findings of diminished protein density of CB1 cannabinoid receptor in uterine tissue exposed to labor support the hypothesis that the endocannabinoid system plays a role in parturition. Our data add to the growing body of evidence indicating the endocannabinoid system is of importance for successful reproduction and support the need for additional research investigating this complex system as it pertains to labor. ClinicalTrials.gov ID: NCT03752021.

Continued Validation of Ultrasound Guidance Targeting Tasks: Relationship with Procedure Performance.

RATIONALE AND OBJECTIVES: To determine if deliberative practice with novel ultrasound guidance targeting tasks improves simulated procedural skill. MATERIALS AND METHODS: In a nonrandomized interventional trial first year medical students practiced the previous described dowel and straw targeting tasks 1 hour a week for 4 weeks (training group) or had no training (controls). Afterward, they each performed a simulated amniocentesis (AMN) and chorionic villus sampling (CVS) procedure. Procedures were scored using a global rating scale (GRS) and compared between groups with Mann-Whitney U tests. Two-way random effects intraclass correlation coefficients for the inter- and intra-rater variability were calculated for each item in both GRS's. RESULTS: The training group (n = 22) had higher scores on several aspects and overall performance of AMN compared to controls (n = 15). There were no differences between groups for CVS. The inter-rater and intra-rater reliability of the GRS's for both AMN and CVS ranged from 0.16 to 0.89 with most values demonstrating good to excellent agreement. CONCLUSION: This study demonstrates validity evidence in the content and internal structure domains for the AMN and CVS simulators and their accompanying GRS's. Repetitive practice of the targeting tasks improved student performance in simulated AMN, but modifications are needed for it to be relevant to other procedures such as CVS.

Sonographic diagnosis of conjoined diamniotic monochorionic twins.

According to traditional theories for the pathogenesis of conjoined twins, diamniotic placentation should not occur. We present an unusual case with diamniotic/monochorionic conjoined twins and discuss possible etiologic hypotheses. The diagnosis of this improbable case was made in the first trimester using ultrasound, which assisted in making an early decision regarding further management.

Cost-effective standardization of preterm labor evaluation.

OBJECTIVE: The purpose of this study was to determine the effect of a standardized evidence-based protocol for preterm labor evaluation on resource use and obstetrics outcomes. STUDY DESIGN: We conducted a retrospective 12-month observational study of patients with symptoms of preterm labor at the Mayo Clinic. All patients underwent triage evaluation per a standardized protocol with a combination of cervical length measurement with contingent fetal fibronectin assay. RESULTS: Of 201 patients who underwent evaluation, 3 women delivered within 7 days, and only 1 woman delivered after a negative evaluation. Mean gestational age at evaluation was 29 weeks 1 day, and delivery was at 38 weeks 3 days of gestation, with an average interval of 57.4 days until delivery. The rate of hospital admission was reduced by 56%, compared with the previous year; an estimated annual cost saving was $39,900. CONCLUSION: Implementation of a standardized protocol for evaluation of preterm labor reduces the rate of unnecessary hospital admissions for observation with consequent significant reduction in expenses.

Evaluation of the Patterns of Learning in the Labor Cervical Examination.

OBJECTIVE: The aim of the study was to evaluate patterns of skill acquisition in the labor cervical examination in novice providers, such as the change in accuracy and overestimation and underestimation over time and the impact of dilation and effacement on accuracy. METHODS: In this descriptive longitudinal study, medical students each performed 120 simulated cervical examinations. Accuracy and how often students overestimated and underestimated dilation and effacement during was determined for each set of 10 repetitions. Accuracy data were grouped and compared by dilation (1-3, 4-6, and 7-10 cm) and effacement (90%, 75%, 50%, and 25%). RESULTS: Student accuracy in dilation significantly improved throughout the course of the study (P < 0.001). At the beginning of the study, students more often overestimated dilation, but this decreased over time (P < 0.001). In addition, the accuracy of the students' estimations was 84%, 62%, and 52% for dilations of 1-3, 4-6, and 7-10 cm, respectively (P < 0.001). Student accuracy in effacement significantly improved throughout the course of the study (P < 0.001). At the beginning of the study, students more often overestimated effacement, but as training progressed, more students tended to overestimate and underestimate equally often (P < 0.001). In addition, accuracy of the students' estimations was 93%, 88%, 81%, and 35% for effacements of 90%, 75%, 50%, and 25%, respectively (P < 0.001). CONCLUSIONS: Knowing that students tend to overestimate cervical dilation and effacement early in training and that cervices of high dilation and low effacement are more difficult to assess will be helpful in designing more efficient cervical examination training regimens.