Strategies to increase the rate of vaginal deliveries after cesarean without negative impact on outcomes.

OBJECTIVE: To compare the rate of vaginal birth after cesarean section (VBAC), including the maternal and perinatal outcomes, in two historical cohorts before and after the implementation of specific changes in the clinical practice. DESIGN: A retrospective cohort study. SETTING: Skåne University Hospital in Malmö, Sweden. PARTICIPANTS: including all women with one previous cesarean section (CS), who delivered during two 4-year periods: 2005-2008 (Group I) and 2013-2016 (Group II). METHODS: Medical records were retrieved from the hospital's computerized medical system. The surgical reports of all women delivered by repeat CS were reviewed and the appearance of the lower uterine segment at CS was assessed. The primary outcome was VBAC. Secondary maternal outcomes were uterine rupture/dehiscence, hysterectomy and blood loss. The secondary perinatal outcomes were cord blood pH < 7.05 and perinatal mortality rate. Differences for categorical data were studied using the chi-square test and Fisher's exact test. To assess differences for continuous data t-tests were used. To determine which factors predicted VBAC both univariate and multivariate logistic regression analysis with the likelihood ratio test were performed. A two-tailed P-value < 0.05 was considered statistically significant FINDINGS: 2017 patients were included to the study: 792 patients in Group I and 1225 in Group II. The rate of trial of labor after cesarean (TOLAC) was 65.0% and 76.9% and the VBAC rate was 49.8% and 62.0% in Group I and II respectively (p < 0.0001). Maternal and perinatal adverse outcomes were not statistically different between the two groups. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Appropriate management of women with one previous CS might increase the VBAC rate without a negative impact on maternal or perinatal outcomes. The antenatal teamwork has the greatest contribution to VBAC rate by increasing the number of women undergoing TOLAC.

Increased pulsatility in the fetal ductus venosus is not related to altered cardiac strain in high-risk pregnancies.

OBJECTIVE: Blood flow velocity patterns in fetal veins are considered to reflect cardiac function, but have not been convincingly documented. The aim of this study was to generate reference values for fetal cardiac strain and compare it with results in fetuses with signs of increased venous pulsatility. METHODS: Cardiac four-chamber loops were prospectively stored and analyzed for strain and strain rate in a cohort of 250 healthy fetuses. The results were compared with recordings in 38 fetuses with increased vascular impedance in the umbilical artery, including several with abnormal blood flow velocities in the ductus venosus (DVs) and umbilical vein. RESULTS: In the control group, strain rate was slightly higher in the right ventricle, but strain and velocities were similar. There was a significant effect of frame rate on the values of strain and strain rate, but not on velocity. No differences in cardiac strain or strain rate were observed between the control group and the compromised fetuses. There was no correlation between changes in venous blood flow and cardiac strain. CONCLUSIONS: Increased venous pulsatility was not related to fetal cardiac strain. This might indicate that the DVs does not primarily open due to increased central venous pressure and that cardiac strain is affected late in the process of moderate fetal hypoxia.

Alterations in ductus venosus velocity indices in relation to umbilical venous pulsations and perinatal outcome.

INTRODUCTION: Abnormal blood velocity in the ductus venosus is more frequently detected than pulsations in the umbilical vein, but both are considered to be indicators of fetal compromise. The aim of this study was to investigate blood flow patterns in the ductus venosus and the association between individual blood velocity ratios and pulsations in the umbilical vein and perinatal outcome. MATERIAL AND METHODS: Retrospective cohort study on Doppler ultrasound examination of ductus venosus and umbilical venous blood velocity in 358 high-risk pregnancies. Ductus venosus blood velocity pattern was analyzed for pulsatility index and the following velocity ratios: S/ES, S/a and ES/a (where S is systole, ES is end-systole, and a is atrial contraction). Ductus venosus ratio z-scores were calculated and related to pulsations in the umbilical vein and adverse perinatal outcome. RESULTS: Systolic ratios in the ductus venosus were less frequently abnormal than ratios taking into account diastolic velocities, particularly at full-term. High S/ES, ES/a ratios and pulsatility index (z-score >2), were all related to presence of pulsations in the umbilical vein. Umbilical venous pulsations were the best indicator of adverse perinatal outcome. CONCLUSIONS: Changes in ductus venosus blood flow during systole occur more rarely than diastolic changes, and alterations in end-diastolic blood velocity in the ductus venosus might give false-positive indications of worsening fetal condition. Umbilical venous pulsations seem to better predict adverse outcome of pregnancy than do indices in the ductus venosus.

Investigations on atrial function in fetuses with signs of impaired placental function.

OBJECTIVE: Cardiac dysfunction has been shown in cases of placental insufficiency, but few reports exist on fetal atrial function. The aim of this study was to generate reference values for atrial strain and compare them to results in fetuses with signs of increased placental resistance and abnormal venous circulation. METHODS: Using a 2D speckle-tracking technique, velocity and strain of the fetal atrial walls were investigated in 250 healthy fetuses and in 40 fetuses with abnormal umbilical Doppler. Influences of gestational age, heart rate, and frame rate on the measurements were investigated and reference curves constructed. RESULTS: Strain and velocity were greater for the right atrial walls compared with the left, and velocity and strain rate increased with gestational age. Increased pulsatility of the ductus venosus and umbilical vein was not associated with altered right atrial function. CONCLUSIONS: 2D speckle-tracking analysis of fetal atrial wall movement seems to be feasible. Atrial function was preserved in fetuses with placental dysfunction, even in cases of increased venous pulsatility.