Leif Gjessing

Prediction of labor and delivery by transperineal ultrasound in pregnancies with prelabor rupture of membranes at term

To evaluate whether engagement of the fetal head or cervical length in women with premature rupture of membranes (PROM) at term, are associated with time from PROM to delivery or need for operative delivery.

Ultrasound assessment of fetal head–perineum distance before induction of labor

To evaluate fetal head–perineum distance measured by ultrasound imaging as a predictive factor for induction of labor, and to compare this distance with maternal factors, the Bishop score and ultrasound measurements of cervical length, cervical angle and occiput position.

Can ultrasound measurements replace digitally assessed elements of the Bishop score

Objective. To compare elements of the Bishop score and corresponding sonographic measurements before induction of labor, and assess how predictive factors can be used in a clinical setting. Design. Prospective comparative clinical study. Setting. Secondary referral center, university hospital. Population. A total of 275 women scheduled for induction of labor. Methods. Fetal head descent to the perineum was assessed with transperineal ultrasound. Cervical length, posterior angle, and dilatation were evaluated with transvaginal ultrasound followed by Bishop score without knowledge of the ultrasound measurements. Results. Univariable regression analyses of successful induction were significant for digital assessment of cervical dilatation, ultrasound measured fetal head–perineum distance ≤40 mm, ultrasound measured cervical length ≤25 mm, and ultrasound measured posterior cervical angle >90 degrees. After adjusting for maternal factors in a multivariable model, estimates were significant for previous vaginal birth (OR 5.3; 95% CI 2.1–13.9, p<0.01), but borderline for maternal height (OR 1.1; 95% CI 1.0–1.2, p = 0.01) and ultrasound measured posterior cervical angle >90 degrees (OR 2.6; 95% CI 1.1–6.1, p = 0.03). A scoring model combining ultrasound measured fetal head–perineum distance, cervical length, cervical posterior angle and digitally assessed cervical dilatation, discriminated successful and failed induction at 71% (95% CI 61–80%, p<0.01) area under the receiver–operating characteristics curve. Conclusion. Digital assessment of fetal head descent, cervical length and position can possibly be replaced with ultrasound measurements. Dilatation is best evaluated with digital assessment. Combination of these four factors can predict success of labor induction.

The term breech presentation. A retrospective study with regard to the planned mode of delivery

Background. To analyze retrospectively a large group of term breech and vertex deliveries, with regard to the influence of the mode of delivery on the frequency of fetal and maternal complications.

A randomized prospective study of misoprostol and dinoproston for induction of labor

Background. Misoprostol, a prostaglandin E1 analog registered for the prevention of gastric ulcers in NSAID‐drug users, has been reported to be more effective for labor induction than the standard prostaglandin, dinoproston after vaginal application. There have been some concerns about possible hyperstimulation of the uterine activity and about the safety for the fetus with this new drug.

Anal sphincter tears at spontaneous delivery: A comparison of five hospitals in Norway

Objective. To analyze circumstances relating to severe anal sphincter tears occurring at spontaneous delivery, in view of reported differences in practice regarding manual perineal protection during delivery. Design. Cohort study of midwife‐conducted non‐operative vaginal deliveries. Setting. Five Norwegian hospitals with 12,438 consecutive deliveries during a 12‐month period. Methods. Data from 357 women sustaining third and fourth grade anal sphincter tears (2.9%) were analyzed. Main outcome measures. Different incidence of major perineal tears. Results. Sphincter tear incidence varied significantly between the five hospitals, from 1.3 to 4.7% (p <0.001, RR=3.14 (CI: 2.38–5.56)). There was no significant difference between the five hospitals when other risk variables were compared. Use of oxytocin in the second phase of labor and of epidural analgesia was significantly more often applied in the hospital with the lowest rate of sphincter tears. The midwives’ perception of having applied perineal support was not significantly different between the two hospitals with the highest and the lowest incidence of sphincter tear. Conclusion. The observed difference in incidence of sphincter tear between the hospitals remains unexplained, but could be due to different perineal protection handling techniques.

Does allocation of low risk parturient women to a separate maternity unit decrease the risk of emergency cesarean section

Objective. To study whether the selection of low risk parturient women into a separate maternity unit leads to a lower risk of emergency cesarean section, compared to giving birth in a unit with mixed cases. Design. Hospital based registry study. Setting. Maternity units in two university hospitals in Oslo, Norway. Population. All low risk parturient women with attempted vaginal deliveries in the years 2001–2003, a total number of 11,686 deliveries. Methods. Data were obtained from standardized patient records and risks of cesarean section were estimated as odds ratios. Main outcome measures. Emergency cesarean section risk. Results. Compared with women giving birth in a unit with mixed cases, women giving birth in a maternity unit with low risk cases only had a higher risk of emergency cesarean section (OR 1.4; 95% CI 1.2–1.6). Conclusions. Giving birth in a low risk maternity unit is associated with a higher risk of cesarean section for low risk parturient women compared with giving birth in a maternity unit with mixed cases.

OC191: Ultrasound measurements of fetal head‐engagement and cervical length as predictive factors of labor outcome in women with induced labor

of fetal head position. An error rate of around 50% for vaginal examination was nearly constant during the first 50 examinations. It decreased subsequently, to stabilize at a low level from the 73rd patient. Errors of ± 180◦ were the most frequent. With regard to the vaginal examination, the learning curve of ultrasound stabilized earlier, after the 23rd patient. The most frequent errors with ultrasound were the absence of conclusion, particularly at the beginning of training, followed by errors of ± 45◦. Conclusions: Learning was easier and accuracy was higher in the determination of fetal head position in labor with transabdominal sonography than with digital examination. This should encourage physicians to introduce ‘clinical ultrasound’ into their practice.

OC140: Ultrasound measurements or Bishop score before induction of labor?

Objectives: 1) To determine the incidence of cord entanglement during early gestation using three dimensional (3D US) sonography. 2) To establish relationship between fetal and umbilical cord lengths, as a suggested pathophysiology for the cord entanglement incidence throughout pregnancy. Material and Methods: A prospective consecutive study was designed and 3D US was performed. Two hundred and thirty seven singleton pregnancies between 13–16 weeks were included. Cord entanglement was defined when one or more of the following was detected: cord around neck, hand, leg, thorax, abdomen shoulder, pelvis. Floating free cord through all its length in the amniotic fluid was defined as normal position cord. Results: Abnormal cord position was observed in 149 (62.9%) patients. Of those: 42.9.0% around neck, 15.4% legs, 12.7% hands, 4.8% -abdomen, 24.2% -other body parts (thorax, shoulder and pelvis). Incidence of total cord entanglement was similar between 13–16 weeks gestation. A decreasing ratio between cord length and CRL (according to literature) was calculated throughout pregnancy. Conclusions: A high incidence of early second trimester cord entanglement was found. This may be explained by the high calculated ratio between cord and fetal lengths during early pregnancy. Cord entanglement should be considered a part of normal early fetal movements and development.

The Bishop score components correlated to sonographic measurements prior to induction of labor

Objective: The Bishop score remains the gold standard for assessing favourability for induction of labor, but it is a subjective evaluation with limitations. The aims of this prospective study were to relate the components of the Bishop score to corresponding sonographic measurements and to assess predictive values for a successful labor induction. Methods: In 275 women the fetal head-perineum distance was measured through a transverse transperineal scan, and the cervical length, posterior cervical angle and cervical dilatation through a transvaginal scan. The Bishop score was assessed without knowledge of ultrasound measurements immediately after the scans. Correlation analyses were done, and receiver-operating characteristics (ROC) curves were used for evaluation of the probability of a successful vaginal delivery. Results: By sonographic assessment the cervix was closed in 219 (80%) of the women compared to 58 (21%) by digital assessment. Spearman\s correlation coefficient for digital and ultrasound assessment of cervical length was 0.54 (p<0.01), fetal head decent 0.23 (p<0.01) and cervical position/angle 0.03. The predictive value for a vaginal delivery after induction of labor for Bishop score and ultrasound measurements is presented in figure 1. The best predictive factors for a vaginal delivery were digital assessment of cervical dilatation with 61%; 95% CI 51–71% (p=0.03) under the ROC curve area, and a combination of ultrasound measured fetal head-perineum distance, cervical length and cervical angle with 67%; 95% CI 56–77% (p<0.01) under the curve area. Conclusion: The correlation between ultrasound and digital assessments is weak. None of the factors used alone are good predictors of labor outcome. Combinations of factors improve the prediction.