UOG Journal Club: April 2013

1. UOG Journal Club: April 2013 Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery T. Ghi, A. Youssef, E. Maroni, T. Arcangeli, F. De Musso, F. Bellussi, M. Nanni, F. Giorgetta, A. M. Morselli-Labate, M. T. Iammarino, A. Paccapelo, L. Cariello, N. Rizzo, G. Pilu Volume 41, Issue 4, Date: April 2013, pages 430–435 Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Y. Gilboa, Z. Kivilevich, M. Spira, E. Katorza, O. Moran, R. Achiron Volume 41, Issue 4, Date: April 2013, pages 436–441 Journal Club slides prepared by Dr Aly Youssef (UOG Editor for Trainees)

2. UOG Journal Club: April 2013 Intrapartum transperineal ultrasound assessment of the fetal head progression in the active second stage and the mode of delivery T. Ghi, A. Youssef, E. Maroni, T. Arcangeli, F. De Musso, F. Bellussi, M. Nanni, F. Giorgetta, A. M. Morselli-Labate, M. T. Iammarino, A. Paccapelo, L. Cariello, N. Rizzo, G. Pilu Volume 41, Issue 4, Date: April 2013, pages 430–435

3. Digital examination in labor is inaccurate and poorly reproducible • Intrapartum transperineal ultrasonography has been suggested as an objective and reliable method in assessing fetal head descent and rotation • Many transperineal ultrasound parameters have been studied. However, very little is known about the dynamic changes and clinical usefulness of these parameters in the second stage of labor

4. Two transperineal ultrasound parameters were assessed in the present study Fetal skull Maternal symphysis pubis ANGLE OF PROGRESSION MIDLINE ANGLE Fetal head midline • Angle of progression • (AoP) • The angle between the pubic symphysis and a line tangential to the fetal skull • Assessed in a mid-sagittal view • Midline angle • (MLA) • The angle between the antero-posterior axis of maternal pelvis and the head midline • Assessed in a transverse view

5. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery Ghi et al., UOG 2013 Objectives Evaluate by 3D ultrasound the longitudinal changes of two transperineal parameters (AoP and MLA) during the active second stage of labor. To assess if the sonographic changes of these two parameters are affected by the mode of delivery.

6. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery Ghi et al., UOG 2013 Methods Transperineal ultrasound volumes were acquired from a series of nulliparous women at term in the active second stage of labor • Exclusion criteria • Cesarean delivery during the first stage of labor • Cesarean or instrumental vaginal delivery performed in the second stage purely due to an abnormal fetal heart trace Inclusion criteria Uncomplicated singleton pregnancies at term gestation (37 weeks or more) Fetuses in cephalic presentation

7. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery Ghi et al., UOG 2013 Methods • 3D volumes were acquired at the beginning of the active second stage (T1), and every 20 minutes thereafter (T2, T3, T4, T5, and T6) until delivery • Both AoPand MLA were calculated after delivery and compared between patients who underwent spontaneous vaginal vsoperative delivery (instrumental or Cesarean delivery) • Univariate and multivariate regression analyses were performed including the two ultrasound parameters in addition to various intrapartum and maternal variables to determine independent predictors of operative delivery in the second stage

8. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery Ghi et al., UOG 2013 Results 76 recruited women 3 excluded due to operative delivery for abnormal fetal heart trace 2 excluded due to Cesarean delivery in the first stage of labor 71 women (174 acquired 3D volumes) 58 (81.7%) spontaneous vaginal delivery 13 (18.3%) operative delivery 8 vacuum 5 Cesarean

9. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery Ghi et al., UOG 2013 Results • Women who underwent a spontaneous vaginal delivery had a wider angle of progression at T1 and T2 when compared with women who underwent operative delivery • On the other hand, women who underwent spontaneous vaginal delivery had a narrower midline angle at T3, T4 and T5

10. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery Ghi et al., UOG 2013 Results • On univariate regression analysis, all parameters (including epidural analgesia, maternal age, BMI and oxytocin use) except gestational age were significantly associated with operative delivery • On multivariate analysis of only ultrasound parameters, both AoP and MLA were independently associated with operative delivery • When maternal and intrapartum variables were also considered in the multivariate analysis, only AoP, epidural analgesia and maternal age were significantly associated with operative delivery

11. Intrapartum transperineal ultrasound assessment of fetal head progression in the active second stage of labor and mode of delivery Ghi et al., UOG 2013 Discussion • Ultrasonographic evidence of poor fetal head descent (as assessed by the angle of progression) can be detected as early as the beginning of the active second stage in cases undergoing operative delivery • A slower head rotation in these cases (as assessed by midline angle) seems to be a late finding (at least 40 minutes from the beginning of the active second stage) • The evaluated ultrasonographic parameters may help predict the mode of delivery together with factors such as epidural analgesia and maternal age

12. Intrapartum transperineal ultrasound assessment of fetal head progression in the active second stage of labor and mode of delivery Ghi et al., UOG 2013 Limitations • The limited number of patients who underwent operative delivery did not permit a separate analysis of the women who underwent vacuum from those who were submitted to cesarean delivery • As all vacuum extractions were successful, no data on the prediction of instrumental delivery success could be provided • The fetal occiput position was not sonographically determined at the beginning of the second stage so the data could not be stratified according to the fetal head position • All ultrasound evaluations were performed in the absence of uterine contractions and maternal pushing

13. Intrapartum transperineal ultrasound assessment of fetal head progression in the active second stage of labor and mode of delivery Ghi et al., UOG 2013 • Larger studies are needed to evaluate the predictive value of ultrasound for the type of operative delivery (vacuum or forceps vs Cesarean delivery) • Further studies are needed to investigate the value of the dynamic changes during uterine contractions and maternal pushing in the prediction of the mode of delivery • The role of ultrasound in the subset of fetuses with posterior occiput remain to be elucidated Future perspectives

14. UOG Journal Club: April 2013 Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Y. Gilboa, Z. Kivilevich, M. Spira, E. Katorza, O. Moran, R. Achiron Volume 41, Issue 4, Date: April 2013, pages 436–441

15. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 Maternal symphysis pubis Fetal head progression distance (HPD) The fetal head progression distance (HPD) represents a line connecting the most distally presenting part of the fetal head to the infra-pubic line (-----), a vertical line from the lower edge of the pubic symphysis

16. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 The aim of this study was to assess the clinical significance, and utility, of the fetal head progression distance in predicting the mode of delivery during prolonged second stage

17. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 Methods 65 term women with prolonged second stage of labor were included • Inclusion criteria • Fetal head station below the ischial spines • Normal fetal heart rate monitoring • Following digital evaluation of fetal head station, HPD was measured during maternal pushing by an operator blinded to clinical examination • The mode of delivery was decided by an obstetrician blinded to ultrasound findings • Binary logistic regression analysis was performed to evaluate the predictive value of the fetal head progression distance for the mode of delivery

18. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 Results 65 women with prolonged second stage (174 acquired 3D volumes) 17 (26.2%) Spontaneous vaginal delivery 48 (73.8%) Operative delivery 32 vacuum 11 Cesarean 5 forceps

19. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 Results • A positive correlation was demonstrated between mean HPD and fetal head station, and between HPD and neonatal head circumference • No statistically significant differences between HPD for the various modes of delivery • Multivariate analysis adjusted for maternal age, gestational age, maternal BMI, parity, previous CS, fetal gender, neonatal head circumference and head position did not show a significant association between HPD and mode of delivery

20. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 No correlation was found between HPD and various classification the mode of delivery MOD1 : Spontaneous vaginal delivery, vacuum, forceps, and Cesarean section delivery as four separated groups MOD2 : Spontaneous vaginal delivery vs operative deliveries (vacuum, forceps, and Cesarean section delivery) as two separated groups MOD3 : Spontaneous vaginal delivery, instrumental deliveries (vacuum, forceps) and Cesarean section delivery, as three separated groups

21. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 Discussion • The present study confirms the correlation between clinical assessment of fetal head station and HPD during labor • Despite this positive correlation, no statistically significant correlation, or predictive value, was found between HPD and mode of delivery • Despite the lack of predictive value for HPD measurement in determining mode of delivery, the finding that HPD correlates well with fetal head station suggests its usefulness as an ancillary tool for assessing fetal head descent during labor

22. Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 Limitations • Small sample size, due to the relatively low number of women who reach prolonged second stage • Lack of comparison to women in the first stage of labor Future perspectives A larger prospective study, including patients evaluated during the first stage of labor, as well as the second, is required to further assess the HPD measurement in the clinical management of labor

23. Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery Ghi et al., UOG 2013 Head progression distance in prolonged second stage of labor: relationship with mode of delivery and fetal head station Gilboa et al., UOG 2013 Discussion points • Should ultrasound be routinely used in the labor ward for fetal head progression assessment? • What are the most reliable ultrasound parameters for monitoring fetal head descent? • What is the clinical situation in which ultrasound may have a role in labor? • How should ultrasound be included in the algorithms of different clinical scenarios?