Can Intrapartum Cardiotocography Predict Uterine Rupture among Women with Prior Caesarean Delivery?: A Population Based Case-Control Study

Predicting the risks and recognizing the signs: a two-year prospective population-based study on pregnant women with uterine rupture in The Netherlands

OBJECTIVE

To estimate the incidence of uterine rupture in the Netherlands and evaluate risk indicators prelabour and during labor of women with adverse maternal and/or perinatal outcome.

METHODS

This is a population-based nationwide study using the Netherlands Obstetrics Surveillance System (NethOSS). We performed a two-year registration of pregnant women with uterine rupture. The first year of registration included both women with complete uterine rupture and women with incomplete (peritoneum intact) uterine rupture. The second year of registration included women with uterine rupture with adverse maternal and/or perinatal outcome. We collected maternal and obstetric characteristics, clinical signs, and symptoms during labor and CTG abnormalities. The main outcome measures were incidence of complete uterine rupture and uterine rupture with adverse outcome and adverse outcome defined as major obstetric hemorrhage, hysterectomy, embolization, perinatal asphyxia and/or (neonatal) intensive care unit admission.

RESULTS

We registered 41 women with a complete uterine rupture (incidence: 2.5 per 10,000 births) and 35 women with uterine rupture with adverse outcome (incidence: 0.9 per 10,000 births). No adverse outcomes were found among women with incomplete uterine rupture. Risk indicators for adverse outcome included previous cesarean section, higher maternal age, gestational age <37 weeks, augmentation of labor, migration background from Sub-Saharan Africa or Asia. Compared to women with uterine rupture without adverse outcomes, women with adverse outcome more often expressed warning symptoms during labor such as abdominal pain (OR 3.34, 95%CI 1.26-8.90) and CTG abnormalities (OR 9.94, 95%CI 2.17-45.65). These symptoms were present most often 20 to 60 min prior to birth.

CONCLUSION

Uterine rupture is a rare condition for which several risk indicators were identified. Maternal symptoms and CTG abnormalities are associated with adverse outcomes and time dependent. Further analysis could provide guidance to expedite delivery.

Clinical analysis of incomplete rupture of the uterus secondary to previous cesarean section

Uterine rupture is a rupture of the body or lower part of the uterus during pregnancy or delivery. Total of 98 cases with incomplete uterine rupture were classified as the incomplete uterine rupture group, 100 cases with a history of cesarean delivery without uterine rupture were classified as the non-ruptured uterus group, and controls were selected using a systematic sampling method. The maternal age ≥35 years were associated with 2.18 times higher odds of having an incomplete uterine rupture. The odd of having an incomplete uterine rupture was 3.744 times higher for a woman with delivery interval ≤36 months. Having pregnancy complication was associated with 3.961 times higher odds of having an incomplete uterine rupture. The neonatal weight was lighter in the incomplete uterine rupture group (P = 0.007). The number of preterm birth and transfer to the NICU were higher in the incomplete uterine rupture group (P ＜ 0.01). The operation time and the length of time in hospital were longer in the group with incomplete uterine rupture (P ＜ 0.01). Age ≥35 years, delivery interval ≤36 month, and pregnancy with complication were independent risk factors of incomplete rupture of the uterus secondary to previous cesarean section.

Optimizing the management of acute, prolonged decelerations and fetal bradycardia based on the understanding of fetal pathophysiology

Any acute and profound reduction in fetal oxygenation increases the risk of anaerobic metabolism in the fetal myocardium and, hence, the risk of lactic acidosis. On the contrary, in a gradually evolving hypoxic stress, there is sufficient time to mount a catecholamine-mediated increase in the fetal heart rate to increase the cardiac output and redistribute oxygenated blood to maintain an aerobic metabolism in the fetal central organs. When the hypoxic stress is sudden, profound, and sustained, it is not possible to continue to maintain central organ perfusion by peripheral vasoconstriction and centralization. In case of acute deprivation of oxygen, the immediate chemoreflex response via the vagus nerve helps reduce fetal myocardial workload by a sudden drop of the baseline fetal heart rate. If this drop in the fetal heart rate continues for >2 minutes (American College of Obstetricians and Gynecologists' guideline) or 3 minutes (National Institute for Health and Care Excellence or physiological guideline), it is termed a prolonged deceleration, which occurs because of myocardial hypoxia, after the initial chemoreflex. The revised International Federation of Gynecology and Obstetrics guideline (2015) considers the prolonged deceleration to be a "pathologic" feature after 5 minutes. Acute intrapartum accidents (placental abruption, umbilical cord prolapse, and uterine rupture) should be excluded immediately, and if they are present, an urgent birth should be accomplished. If a reversible cause is found (maternal hypotension, uterine hypertonus or hyperstimulation, and sustained umbilical cord compression), immediate conservative measures (also called intrauterine fetal resuscitation) should be undertaken to reverse the underlying cause. In reversible causes of acute hypoxia, if the fetal heart rate variability is normal before the onset of deceleration, and normal within the first 3 minutes of the prolonged deceleration, then there is an increased likelihood of recovery of the fetal heart rate to its antecedent baseline within 9 minutes with the reversal of the underlying cause of acute and profound reduction in fetal oxygenation. The continuation of the prolonged deceleration for >10 minutes is termed "terminal bradycardia," and this increases the risk of hypoxic-ischemic injury to the deep gray matter of the brain (the thalami and the basal ganglia), predisposing to dyskinetic cerebral palsy. Therefore, any acute fetal hypoxia, which manifests as a prolonged deceleration on the fetal heart rate tracing, should be considered an intrapartum emergency requiring an immediate intervention to optimize perinatal outcome. In uterine hypertonus or hyperstimulation, if the prolonged deceleration persists despite stopping the uterotonic agent, then acute tocolysis is recommended to rapidly restore fetal oxygenation. Regular clinical audit of the management of acute hypoxia, including the "the onset of bradycardia to delivery interval," may help identify organizational and system issues, which may contribute to poor perinatal outcomes.

Unexpected Uterine Rupture-A Case Report, Review of the Literature and Clinical Suggestions

BACKGROUND AND OBJECTIVES

Women with a history of cesarean section are a high-risk group because they are likely to develop uterine rupture during their next pregnancy. Current evidence suggests that a vaginal birth after cesarean section (VBAC) is associated with lower maternal mortality and morbidity than elective repeat cesarean delivery (ERCD). Additionally, research suggests that uterine rupture can occur in 0.47% of cases of trial of labor after cesarean section (TOLAC).

CASE DESCRIPTION

A healthy 32-year-old woman at 41 weeks of gestation, in her fourth pregnancy, was admitted to the hospital due to a dubious CTG record. Following this, the patient gave birth vaginally, underwent a cesarean section, and successfully underwent a VBAC. Due to her advanced gestational age and favorable cervix, the patient qualified for a trial of vaginal labor (TOL). During labor induction, she displayed a pathological CTG pattern and presented symptoms such as abdominal pain and heavy vaginal bleeding. Suspecting a violent uterine rupture, an emergency cesarean section was performed. The presumed diagnosis was confirmed during the procedure-a full-thickness rupture of the pregnant uterus was found. The fetus was delivered without signs of life and successfully resuscitated after 3 min. The newborn girl of weight 3150 g had an Apgar score of 0/6/8/8 at 1, 3, 5, and 10 min. The uterine wall rupture was closed with two layers of sutures. The patient was discharged 4 days after the cesarean section without significant complications, with a healthy newborn girl.

CONCLUSIONS

Uterine rupture is a rare but severe obstetric emergency and can be associated with maternal and neonatal fatal outcomes. The risk of uterine rupture during a TOLAC attempt should always be considered, even if it is a subsequent TOLAC.

Risk factors and outcomes associated with type of uterine rupture

PURPOSE

To identify risk factors associated with the occurrence of complete uterine rupture (CUR) in comparison to partial uterine rupture (PUR) to further investigate to what extent a standardized definition is needed and what clinical implications can be drawn.

METHODS

Between 2005 and 2017 cases with CUR and PUR at Charité University Berlin, Germany were retrospectively identified. Demographic, obstetric and outcome variables were analyzed regarding the type of rupture. Binary multivariate regression analysis was conducted to identify risk factors associated with CUR. In addition, the intended route of delivery (trial of labor after cesarean delivery (TOLAC) and elective repeat cesarean delivery (ERCD)), divided according to the type of rupture, was compared.

RESULTS

92 cases with uterine rupture were identified out of a total of 64.063 births (0.14%). Puerperal complications were more frequent in CUR (67.9 versus 41.1%, p = 0.021). Multiparity ≥ 3 was more frequent in CUR (31 versus 10.7%, p = 0.020). Factors increasing the risk for CUR were parity ≥ 3 (OR = 3.8, p = 0.025), previous vaginal birth (OR = 4.4, p = 0.011), TOLAC (OR = 6.5, p < 0.001) and the use of oxytocin (OR = 2.9, p = 0.036). After multivariate analysis, the only independent risk factor associated with CUR was TOLAC (OR = 7.4, p = 0.017).

CONCLUSION

TOLAC is the only independent risk factor for CUR. After optimized antenatal counselling TOLAC and ERCD had comparable short-term maternal and fetal outcomes in a high resource setting. A high number of previous vaginal births does not eliminate the risk of uterine rupture. A clear distinction between CUR and PUR is essential to ensure comparability among studies.

Interobserver agreement in analysis of cardiotocograms recorded during trial of labor after cesarean

Introduction: To examine interobserver agreement in intrapartum cardiotocography (CTG) classification in women undergoing trial of labor after a cesarean section (TOLAC) at term with or without complete uterine rupture. Materials and methods: Nineteen blinded and independent Danish obstetricians assessed CTG tracings from 47 women (174 individual pages) with a complete uterine rupture during TOLAC and 37 women (133 individual pages) with no uterine rupture during TOLAC. Individual pages with CTG tracings lasting at least 20 min were evaluated by three different assessors and counted as an individual case. The tracings were analyzed according to the modified version of the Federation of Gynaecology and Obstetrics (FIGO) guidelines elaborated for the use of STAN (ST-analysis). Occurrence of defined abnormalities was recorded and the tracings were classified as normal, suspicious, pathological, or preterminal. The interobserver agreement was evaluated using Fleiss' kappa. Results: Agreement on classification of a preterminal CTG was almost perfect. The interobserver agreement on normal, suspicious or pathological CTG was moderate to substantial. Regarding the presence of severe variable decelerations, the agreement was moderate. No statistical difference was found in the interobserver agreement between classification of tracings from women undergoing TOLAC with and without complete uterine rupture. Conclusions: The interobserver agreement on classification of CTG tracings from high-risk deliveries during TOLAC is best for assessment of a preterminal CTG and the poorest for the identification of severe variable decelerations.

Tocogram characteristics of uterine rupture: a systematic review

PURPOSE

Timely diagnosing a uterine rupture is challenging. Based on the pathophysiology of complete uterine wall separation, changes in uterine activity are expected. The primary objective is to identify tocogram characteristics associated with uterine rupture during trial of labor after cesarean section. The secondary objective is to compare the external tocodynamometer with intrauterine pressure catheters.

METHODS

MEDLINE, EMBASE, and the Cochrane library were systematically searched for eligible records. Moreover, clinical guidelines were screened. Studies analyzing tocogram characteristics of uterine rupture during trial of labor after cesarean section were appraised and included by two independent reviewers. Due to heterogeneity, a meta-analysis was only feasible for uterine hyperstimulation.

RESULTS

Thirteen studies were included. Three tocogram characteristics were associated with uterine rupture. (1) Hyperstimulation was more frequently observed compared with controls during the delivery (38 versus 21 % and 58 versus 53 %), and in the last 2 h prior to birth (19 versus 4 %). Results of meta-analysis: OR 1.68 (95 % CI 0.97-2.89), p = 0.06. (2) Decrease of uterine activity was observed in 14-40 % and (3) an increasing baseline in 10-20 %. Five studies documented no changes in uterine activity or Montevideo units. A direct comparison between external tocodynamometer and intrauterine pressure catheters was not feasible.

CONCLUSIONS

Uterine rupture can be preceded or accompanied by several types of changes in uterine contractility, including hyperstimulation, reduced number of contractions, and increased or reduced baseline of the uterine tonus. While no typical pattern has been repeatedly reported, close follow-up of uterine contractility is advised and hyperstimulation should be prevented.