http://informahealthcare.com/jmf ISSN: 1476-7058 (print), 1476-4954 (electronic) J Matern Fetal Neonatal Med, 2014; 27(15): 1560–1563 ! 2014 Informa UK Ltd. DOI: 10.3109/14767058.2013.868430
ORIGINAL ARTICLE
Ultrasound imaging in prolonged second stage of labor: does it reduce the operative delivery rate?
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 06/22/15 For personal use only.
Bianca Masturzo, Daniele De Ruvo, Pietro Gaglioti, and Tullia Todros Department of Surgical Sciences, Maternal-Fetal Medicine Unit, Sant’Anna Hospital, University of Turin, Turin, Italy
Abstract
Keywords
Objective: To reduce the operative delivery rate in the prolonged second stage of labor (PSSL) through intrapartum sonography. Methods: Sixty-two women – with uncomplicated pregnancies at term, fetus in cephalic presentation and occipitoanterior position, in PSSL – had already undergone epidural anesthesia and oxytocin infusion. Transperineal ultrasound was performed to define fetal head direction (downward, horizontal, and upward) and patients were divided into three groups (D, H, and U). Proposed protocol: Cessation of oxytocin infusion, addition of a dose of anesthesia, invitation to assume a hand-and-knee position, and to relax. After one hour, oxytocin infusion was started again and women were invited to push. Fetal well-being ensured by cardiotocography (CTG). Chi-square test was used to compare the mode of delivery: cesarean section (CS), vacuum extraction (VE), and spontaneous delivery (SD). Results: Group D (n ¼ 20): 4 SD (20%), 4 VE, 12 CS; group H (n ¼ 22): 9 SD (41%), 9 VE, 4 CS; group U (n20): 16 SD (80%), 4 VE. The risk of not having a SD in group D versus U is quadrupled (RR 4; 95% CI 1.6–9.9). Conclusions: Ultrasound diagnosis of fetal head upward direction is highly predictive of SD in case of PSSL. Further studies are needed to assess this hypothesis.
Hand and knee position, oxytocin, spontaneous delivery, transperineal ultrasound
Introduction American College of Obstetricians and Gynecologists (ACOG) has defined prolonged second stage of labor (PSSL) as a lack of continuing progress of fetal descent for 1–2 h (two hours if epidural anesthesia is injected) in multiparous women, and for 2–3 h in nulliparous women [1]. The incidence of PSSL is up to 17% of all pregnancies [2]. The ideal management should maximize the possibility of spontaneous delivery (SD), minimizing at the same time the probability of maternal and fetal negative outcomes [3–5]. It has recently been suggested that intra-partum ultrasonography may be useful in assessing fetal head engagement, station, and position [6–12]. This is obtained through a transperineal ultrasound (TPU) as described by Kalache et al. [8], Barbera et al. [9], and Henrich et al. [10]. In the management of labor, there is extensive evidence that, compared to the ultrasound diagnosis, the digital pelvic examination does not provide accurate assessment of both the position and the station of fetal head engagement [11]. In the case of PSSL, instrumental delivery is an integral part of Address for correspondence: Bianca Masturzo, Department of Surgical Sciences, Maternal-Fetal Medicine Unit, Sant’Anna Hospital, University of Turin, Via Ventimiglia 3, Turin, Italy. E-mail: bmasturzo@ cittadellasalute.to.it
History Received 30 September 2013 Accepted 19 November 2013 Published online 19 December 2013
obstetric care. An important determinant of a successful and safe use of vacuum or forceps is the correct determination of the fetal head position and station. The incidence of intracranial hemorrhage increases from 1/860 with vacuum delivery to 1/334 with caesarean section (CS) after failed operative delivery with vacuum extraction (VE) [1]. Additionally, the maternal risks of second-stage CS include major hemorrhage and greater risk of bladder trauma [3,6–7]. Therefore, an appropriate decision is mandatory when there is failure to progress in the second stage of labor [8]. There is a high probability to increase the percentage of SD reducing the wrong diagnosis of fetal head position and station through ultrasonography. Ghi et al. [12] introduced a TPU technique to categorize the station of the fetal head through the assessment of its direction in longitudinal translabial sonograms. Du¨ckelmann et al. [13] have already suggested that TPU in patients with a PSSL may change obstetrical practice by reducing the number of second stage CS without increasing maternal and neonatal morbidity. The purpose of our study is to assess the possibility of a SD in a selected population with PSSL. Based on our findings, we speculate that with an adequate management, obtained through a correct US diagnosis of fetal head station, it is possible to reduce VE or CS, increasing SD.
US in labor to reduce the operative delivery rate?
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 06/22/15 For personal use only.
DOI: 10.3109/14767058.2013.868430
1561
Figure 1. Transperineal Ultrasound (TPU): the transducer is positioned translabially along the sagittal plane.
Figure 2. TPU fetal head direction compared with schematic representation: upward direction, fetal head in the lower one-third of the pelvis.
Materials and methods
The study group included 62 uncomplicated singleton pregnancies at term of gestation (37 weeks or more) with fetuses in cephalic presentation and occipitoanterior position, and a clinical diagnosis of PSSL according to the ACOG criteria: 28 women were nulliparous and 34 pluriparous. A sonographic assessment of fetal head position was performed to all the patients by two operators. All the patients previously informed about the nature of the ultrasound scan and orally consented. The transducer (portable Philips Clear Vue 550 C5-2, 2–5 MHz transabdominal convex transducer, Amsterdam, The Netherlands) was positioned sovrapubically, rotated in the transverse plane to identify the position of the occiput by demonstrating the fetal orbits, midline – defined as the echogenic line interposed between the two cerebral hemispheres – and cervical spine [14]. At the time of diagnosis of PSSL, all the patients were treated following the guidelines in the literature [15]: 5 units of oxytocin were solved in 500 cc saline solution and infused i.v. starting with 5 ml/h and increasing the dose of 5 ml every 15 min, until the onset of effective uterine contractions (average dose: 30– 40 ml/h), and fetal wellness was monitored by continuous cardiotocography (CTG). All the women were treated with epidural anesthesia with fentanyl 100 mcg and levobupivacaine (chirocaine) 0.0625%. A TPU assessment of fetal head direction was performed with the technique described by Ghi et al. [12] (Figure 1). We approached a dynamic assessment: in real time, during maternal pushing, observing fetal head direction. The patients were divided into three groups, depending on the direction of the fetal head, which was categorized as follows: Downward (group D): fetal head is in the upper third of the pelvis, with clinical station most frequently at þ1 cm. Horizontal (group H): fetal head is in the midpelvis, most frequently at þ2 cm. Upward (group U): it indicates that the head is most likely in the lower third of the pelvis, at þ3 cm. (Figure 2). In all the patients, we proposed one hour of stand-by during which we: discontinuate the infusion of oxytocin [16];
add a dose of epidural analgesia with levobupivacaine (chirocaine) 0.125% [17]; invitate to assume a hand and knee or upright position [18]; invitate to avoid abdominal pushing. After this one hour of stand-by, oxytocin was reinfused, and women were invited to restart pushing during uterine contractions. In all cases, continuous CTG showed fetal well being. Chi-square test was used to compare the mode of delivery (CS, VE, and SD) among the three groups.
Results In group D, in which the ultrasound fetal head direction was downward, we observed 20 cases. The mode of delivery was a CS in 12 cases (60.0%), a VE in 4 cases (20.0%), and a SD in 4 cases (20.0%). In group H (horizontal direction), we observed 22 cases. The mode of delivery was a CS in 9 cases (41.0%), a VE in 9 cases (41.0%), and a SD in 4 cases (18.0%). Twenty cases were in group U (upward direction). The mode of delivery was n VE in four cases (20.00%) and a SD in 16 cases (80.0%). No CS was performed in this group. The risk of not having a SD in group D versus group U is quadrupled (p ¼ 5 104 RR 4.0; 95% CI 1.6–9.9), and its doubled when comparing group H versus group U (p ¼ 0.02 RR ¼ 2.1; 95% CI 1.2–3.8). No statistically significant (SS) difference between in the mode of delivery in group D versus H was observed. No adverse maternal events, including post-partum hemorrhage, were observed in all the patients. No neonatal adverse outcome was observed. The average APGAR index in each group at 10 was 47. No significant differences of neonatal weight were observed in the three groups. Actually, only the incidence of BMI 26 (Table 1) appears to be SS different in the three groups (2 3 contingency tables analyzed with Chi-square test – p ¼ 0.01).
Discussion At Sant’Anna Hospital of Turin, Italy – among 7840 deliveries in 2011, the incidence of PSSL had been 13%, with 100% of operative delivery rate. The aim of our study is to assess if it is possible to reduce the operative delivery rate through the use of US during labor. After the diagnosis of PSSL, instead of performing a VE or a CS, through the TPU we could define the level of the
1562
B. Masturzo et al.
J Matern Fetal Neonatal Med, 2014; 27(15): 1560–1563
Table 1. Comparison between the three groups and their relative parameters and mode of delivery.
Maternal age (years) Fetal weight APGAR index 10 APGAR index 50 BMI Spontaneous delivery Vacuum extraction Cesarean section
Group D
Group H
Group U
Anova
Kruskall–Wallis
31.6 5.35 3496.5 426.7 7.85 8.65 25.6 2.2 4 2 8
29.18 4.14 3543.64 346.4 8.00 8.73 24.6 1.9 9 7 3
30.7 5.41 3521.0 409.5 7.70 8.7 23.9 1.6 13 3 0
0.27 0.0645833 0.45 0.0645833 0.02
0.38 0.063194 0.49 0.068056 0.04
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 06/22/15 For personal use only.
Underlined values: an higher BMI seems to be correlated with an high risk of arrested second stage of labor in the upper third and mild part of the pelvis.
fetal head in the pelvis observing its direction (downward, horizontal, or upward). Our data show that an US diagnosis of upward direction, which indicates that fetal head is most likely in the lower third of the pelvis, can be highly predictive of spontaneous vaginal delivery. In our protocol, we opted for a stand-by time of one more hour. Extending the duration of the second stage of labor often allows women to achieve vaginal delivery successfully. Rouse et al. [19] demonstrated that, by simply extending the time interval from 2 h to 4 h, 450% of women in spontaneous labor would proceed to a vaginal delivery. We should suppose that a part of this percentage includes the women who probably would have a TPU fetal head upward direction. Most studies report successful operative vaginal delivery in cases of upward direction, [4,5,9]. No studies have shown the correlation between spontaneous vaginal delivery and fetal head direction in a PSSL. Our results could be due to our management protocol, in particular, the request of maternal pushing delay for one hour after the diagnosis. We suppose that the stand-by hour might allow the fetus to modify its position, even when it is already critical (at the lower third of the pelvis). The maternal hand and knee or upright position should be the best for the fetus to reduce its head pressure against the maternal pelvis bones [20]. We can suppose that the stand-by hour could be useful to perform a SD in those patients with the fetal head already at the lower third of the pelvis. The cessation of the oxytocin infusion should be useful for the uterus relief. A period of uterine relaxation also allows to recover the contraction strength for the delivery, probably due to the reduction of lactic acid in the myometrium and to an increase of O(2) saturation. The actual management of dysfunctional labor with oxytocin may cause an increase of an inefficient uterine contraction if patient has a background of lactate acidosis [21]. Several studies observed that a PSSL could be associated to side effects like post-partum hemorrhage [14]. In our study, no collateral effects were observed, probably due to the cessation of maternal pushing and/or the cessation of oxytocin infusion. This is the first study correlated with the TPU that investigates the possibility of a SD in the PSSL. A limit of our work is represented by the population sample size even if results are SS. Further studies are needed to assess this hypothesis; however, it appears that the diagnosis of upward direction is useful in clinical management of the arrested second stage of labor. In contrast, it is not that clear
whether the diagnoses of horizontal or downward direction can have an impact in clinical management.
Acknowledgements The authors wish to thank Laura Bergamasco, Full Professor at the Department of Physics at Turin University, for the precious work regarding statistical analysis, and Dr. Lorella Vesentini for the enthusiastic cooperation regarding drawing Figures 1 and 2.
Declaration of interest The authors report no declarations of interest.
References 1. American College of Obstetricians and Gynecologists. Operative vaginal delivery. 17. Washington, DC: The College; 2000. 2. Yvonne W, Cheng MD, Linda M, et al. How long is too long: does a prolonged second stage of labor in nulliparous women affect maternal and neonatal outcomes? Am J Obstet Gynecol 2004;191: 933–8. 3. Saunders NG, Paterson CM, Wardworth J. Neonatal and maternal morbidity in relation to the length of the second stage of labour. BJOG 1992;99:381–5. 4. Yli BM, Kro GA, Rasmussen S, et al. How does the duration of active pushing in labor affect neonatal outcomes? J Perinat Med 2011;40:171–8. 5. Murphy DJ, Macleod M, Bahl R, Strachan B. A cohort study of maternal and neonatal morbidity in relation to use of sequential instruments at operative vaginal delivery. Eur J Obstet Gynecol Reprod Biol 2011;156:41–5. 6. Dietz HP, Lanzarone V. Measuring engagement of the fetal head: validity and reproducibility of a new ultrasound technique. Ultrasound Obstet Gynecol 2005;25:165–8. 7. Lu MC, Muthengi E, Wakeel F, et al. Prolonged second stage of labor and postpartum hemorrhage. J Matern Fetal Neonatal Med 2009;22:227–32. 8. Kalache KD, Du¨ckelmann AM, Michaelis SAM, et al. Transperineal ultrasound imaging in prolonged second stage of labor with occipitoanterior presenting fetuses: how well does the ‘angle of progression’ predict the mode of delivery? Ultrasound Obstet Gynecol 2009;33:326–30. 9. Barbera A, Pombar X, Perugino G, et al. A new method to assess fetal head descent in labor with transperineal ultrasound. Ultrasound Obstet Gynecol 2009;33:313–9. 10. Henrich W, Dudenhausen J, Fuchs I, et al. Intrapartum translabial ultrasound (ITU): sonographic landmarks and correlation with successful vacuum extraction. Ultrasound Obstet Gynecol 2006;28: 753–60. 11. Sherer DM, Miodovnik M, Bradley KS, Langer O. Intrapartum fetal head position II: comparison between transvaginal digital examination and transabdominal ultrasound assessment during the second stage of labor. Ultrasound Obstet Gynecol 2002;19:264–8.
US in labor to reduce the operative delivery rate?
DOI: 10.3109/14767058.2013.868430
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 06/22/15 For personal use only.
12. Ghi T, Farina A, Pedrazzi A, et al. Diagnosis of station and rotation of the fetal head in the second stage of labor with intrapartum translabial ultrasound. Ultrasound Obstet Gynecol 2009;33:331–6. 13. Du¨ckelmann AM, Michaelis SA, Bamberg C, et al. Impact of intrapartal ultrasound to assess fetal head position and station on the type of obstetrical interventions at full cervical dilatation. J Matern Fetal Neonatal Med 2012;25:484–8. 14. Akmal S, Tsoi E, Kametas N, et al. Intrapartum sonography to determine fetal head position. J Matern Fetal Neonatal Med 2002; 12:172–7. 15. National Collaborating Centre for Women’s and Children’s Health. Intrapartum care. Care of healthy women and their babies during childbirth. Royal College of Obstetricians and Gynaecologists; 2007. 16. Emin Ustunyurt, Mustafa Ugur, Basak Ozlem Ustunyurt, et al. Prospective randomized study of oxytocin discontinuation after the
17. 18. 19. 20. 21.
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active stage of labor is established. J Obstet Gynaecol Res 2007;33: 799–803. Anim-Somuah M, Smyth RM, Jones L. Epidural versus nonepidural or no analgesia in labour (Review). The Cochrane Collaboration 2011;(12):CD000331. Hunter S, Hofmeyr GJ, Kulier R. Hands and knees posture in late pregnancy or labour for fetal malposition (lateral or posterior) (Review). The Cochrane Collaboration 2007;(4):CD001063. Rouse DJ, Owen J, Savage KG, Hauth JC. Active phase labor arrest: revisiting the 2-hour minimum. Obstet Gynecol 2001;98: 550–4. Gupta JK, Hofmeyr GJ, Shehmar M. Position in the second stage of labour for women without epidural anaesthesia (Review). The Cochrane Collaboration 2012;5:CD002006. Quenby S, Pierce SJ, Brigham S, Wray S. Dysfunctional labor and myometrial lactic acidosis. Obstet Gynecol 2004;103: 718–23.
ORIGINAL ARTICLE
Ultrasound imaging in prolonged second stage of labor: does it reduce the operative delivery rate?
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 06/22/15 For personal use only.
Bianca Masturzo, Daniele De Ruvo, Pietro Gaglioti, and Tullia Todros Department of Surgical Sciences, Maternal-Fetal Medicine Unit, Sant’Anna Hospital, University of Turin, Turin, Italy
Abstract
Keywords
Objective: To reduce the operative delivery rate in the prolonged second stage of labor (PSSL) through intrapartum sonography. Methods: Sixty-two women – with uncomplicated pregnancies at term, fetus in cephalic presentation and occipitoanterior position, in PSSL – had already undergone epidural anesthesia and oxytocin infusion. Transperineal ultrasound was performed to define fetal head direction (downward, horizontal, and upward) and patients were divided into three groups (D, H, and U). Proposed protocol: Cessation of oxytocin infusion, addition of a dose of anesthesia, invitation to assume a hand-and-knee position, and to relax. After one hour, oxytocin infusion was started again and women were invited to push. Fetal well-being ensured by cardiotocography (CTG). Chi-square test was used to compare the mode of delivery: cesarean section (CS), vacuum extraction (VE), and spontaneous delivery (SD). Results: Group D (n ¼ 20): 4 SD (20%), 4 VE, 12 CS; group H (n ¼ 22): 9 SD (41%), 9 VE, 4 CS; group U (n20): 16 SD (80%), 4 VE. The risk of not having a SD in group D versus U is quadrupled (RR 4; 95% CI 1.6–9.9). Conclusions: Ultrasound diagnosis of fetal head upward direction is highly predictive of SD in case of PSSL. Further studies are needed to assess this hypothesis.
Hand and knee position, oxytocin, spontaneous delivery, transperineal ultrasound
Introduction American College of Obstetricians and Gynecologists (ACOG) has defined prolonged second stage of labor (PSSL) as a lack of continuing progress of fetal descent for 1–2 h (two hours if epidural anesthesia is injected) in multiparous women, and for 2–3 h in nulliparous women [1]. The incidence of PSSL is up to 17% of all pregnancies [2]. The ideal management should maximize the possibility of spontaneous delivery (SD), minimizing at the same time the probability of maternal and fetal negative outcomes [3–5]. It has recently been suggested that intra-partum ultrasonography may be useful in assessing fetal head engagement, station, and position [6–12]. This is obtained through a transperineal ultrasound (TPU) as described by Kalache et al. [8], Barbera et al. [9], and Henrich et al. [10]. In the management of labor, there is extensive evidence that, compared to the ultrasound diagnosis, the digital pelvic examination does not provide accurate assessment of both the position and the station of fetal head engagement [11]. In the case of PSSL, instrumental delivery is an integral part of Address for correspondence: Bianca Masturzo, Department of Surgical Sciences, Maternal-Fetal Medicine Unit, Sant’Anna Hospital, University of Turin, Via Ventimiglia 3, Turin, Italy. E-mail: bmasturzo@ cittadellasalute.to.it
History Received 30 September 2013 Accepted 19 November 2013 Published online 19 December 2013
obstetric care. An important determinant of a successful and safe use of vacuum or forceps is the correct determination of the fetal head position and station. The incidence of intracranial hemorrhage increases from 1/860 with vacuum delivery to 1/334 with caesarean section (CS) after failed operative delivery with vacuum extraction (VE) [1]. Additionally, the maternal risks of second-stage CS include major hemorrhage and greater risk of bladder trauma [3,6–7]. Therefore, an appropriate decision is mandatory when there is failure to progress in the second stage of labor [8]. There is a high probability to increase the percentage of SD reducing the wrong diagnosis of fetal head position and station through ultrasonography. Ghi et al. [12] introduced a TPU technique to categorize the station of the fetal head through the assessment of its direction in longitudinal translabial sonograms. Du¨ckelmann et al. [13] have already suggested that TPU in patients with a PSSL may change obstetrical practice by reducing the number of second stage CS without increasing maternal and neonatal morbidity. The purpose of our study is to assess the possibility of a SD in a selected population with PSSL. Based on our findings, we speculate that with an adequate management, obtained through a correct US diagnosis of fetal head station, it is possible to reduce VE or CS, increasing SD.
US in labor to reduce the operative delivery rate?
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 06/22/15 For personal use only.
DOI: 10.3109/14767058.2013.868430
1561
Figure 1. Transperineal Ultrasound (TPU): the transducer is positioned translabially along the sagittal plane.
Figure 2. TPU fetal head direction compared with schematic representation: upward direction, fetal head in the lower one-third of the pelvis.
Materials and methods
The study group included 62 uncomplicated singleton pregnancies at term of gestation (37 weeks or more) with fetuses in cephalic presentation and occipitoanterior position, and a clinical diagnosis of PSSL according to the ACOG criteria: 28 women were nulliparous and 34 pluriparous. A sonographic assessment of fetal head position was performed to all the patients by two operators. All the patients previously informed about the nature of the ultrasound scan and orally consented. The transducer (portable Philips Clear Vue 550 C5-2, 2–5 MHz transabdominal convex transducer, Amsterdam, The Netherlands) was positioned sovrapubically, rotated in the transverse plane to identify the position of the occiput by demonstrating the fetal orbits, midline – defined as the echogenic line interposed between the two cerebral hemispheres – and cervical spine [14]. At the time of diagnosis of PSSL, all the patients were treated following the guidelines in the literature [15]: 5 units of oxytocin were solved in 500 cc saline solution and infused i.v. starting with 5 ml/h and increasing the dose of 5 ml every 15 min, until the onset of effective uterine contractions (average dose: 30– 40 ml/h), and fetal wellness was monitored by continuous cardiotocography (CTG). All the women were treated with epidural anesthesia with fentanyl 100 mcg and levobupivacaine (chirocaine) 0.0625%. A TPU assessment of fetal head direction was performed with the technique described by Ghi et al. [12] (Figure 1). We approached a dynamic assessment: in real time, during maternal pushing, observing fetal head direction. The patients were divided into three groups, depending on the direction of the fetal head, which was categorized as follows: Downward (group D): fetal head is in the upper third of the pelvis, with clinical station most frequently at þ1 cm. Horizontal (group H): fetal head is in the midpelvis, most frequently at þ2 cm. Upward (group U): it indicates that the head is most likely in the lower third of the pelvis, at þ3 cm. (Figure 2). In all the patients, we proposed one hour of stand-by during which we: discontinuate the infusion of oxytocin [16];
add a dose of epidural analgesia with levobupivacaine (chirocaine) 0.125% [17]; invitate to assume a hand and knee or upright position [18]; invitate to avoid abdominal pushing. After this one hour of stand-by, oxytocin was reinfused, and women were invited to restart pushing during uterine contractions. In all cases, continuous CTG showed fetal well being. Chi-square test was used to compare the mode of delivery (CS, VE, and SD) among the three groups.
Results In group D, in which the ultrasound fetal head direction was downward, we observed 20 cases. The mode of delivery was a CS in 12 cases (60.0%), a VE in 4 cases (20.0%), and a SD in 4 cases (20.0%). In group H (horizontal direction), we observed 22 cases. The mode of delivery was a CS in 9 cases (41.0%), a VE in 9 cases (41.0%), and a SD in 4 cases (18.0%). Twenty cases were in group U (upward direction). The mode of delivery was n VE in four cases (20.00%) and a SD in 16 cases (80.0%). No CS was performed in this group. The risk of not having a SD in group D versus group U is quadrupled (p ¼ 5 104 RR 4.0; 95% CI 1.6–9.9), and its doubled when comparing group H versus group U (p ¼ 0.02 RR ¼ 2.1; 95% CI 1.2–3.8). No statistically significant (SS) difference between in the mode of delivery in group D versus H was observed. No adverse maternal events, including post-partum hemorrhage, were observed in all the patients. No neonatal adverse outcome was observed. The average APGAR index in each group at 10 was 47. No significant differences of neonatal weight were observed in the three groups. Actually, only the incidence of BMI 26 (Table 1) appears to be SS different in the three groups (2 3 contingency tables analyzed with Chi-square test – p ¼ 0.01).
Discussion At Sant’Anna Hospital of Turin, Italy – among 7840 deliveries in 2011, the incidence of PSSL had been 13%, with 100% of operative delivery rate. The aim of our study is to assess if it is possible to reduce the operative delivery rate through the use of US during labor. After the diagnosis of PSSL, instead of performing a VE or a CS, through the TPU we could define the level of the
1562
B. Masturzo et al.
J Matern Fetal Neonatal Med, 2014; 27(15): 1560–1563
Table 1. Comparison between the three groups and their relative parameters and mode of delivery.
Maternal age (years) Fetal weight APGAR index 10 APGAR index 50 BMI Spontaneous delivery Vacuum extraction Cesarean section
Group D
Group H
Group U
Anova
Kruskall–Wallis
31.6 5.35 3496.5 426.7 7.85 8.65 25.6 2.2 4 2 8
29.18 4.14 3543.64 346.4 8.00 8.73 24.6 1.9 9 7 3
30.7 5.41 3521.0 409.5 7.70 8.7 23.9 1.6 13 3 0
0.27 0.0645833 0.45 0.0645833 0.02
0.38 0.063194 0.49 0.068056 0.04
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 06/22/15 For personal use only.
Underlined values: an higher BMI seems to be correlated with an high risk of arrested second stage of labor in the upper third and mild part of the pelvis.
fetal head in the pelvis observing its direction (downward, horizontal, or upward). Our data show that an US diagnosis of upward direction, which indicates that fetal head is most likely in the lower third of the pelvis, can be highly predictive of spontaneous vaginal delivery. In our protocol, we opted for a stand-by time of one more hour. Extending the duration of the second stage of labor often allows women to achieve vaginal delivery successfully. Rouse et al. [19] demonstrated that, by simply extending the time interval from 2 h to 4 h, 450% of women in spontaneous labor would proceed to a vaginal delivery. We should suppose that a part of this percentage includes the women who probably would have a TPU fetal head upward direction. Most studies report successful operative vaginal delivery in cases of upward direction, [4,5,9]. No studies have shown the correlation between spontaneous vaginal delivery and fetal head direction in a PSSL. Our results could be due to our management protocol, in particular, the request of maternal pushing delay for one hour after the diagnosis. We suppose that the stand-by hour might allow the fetus to modify its position, even when it is already critical (at the lower third of the pelvis). The maternal hand and knee or upright position should be the best for the fetus to reduce its head pressure against the maternal pelvis bones [20]. We can suppose that the stand-by hour could be useful to perform a SD in those patients with the fetal head already at the lower third of the pelvis. The cessation of the oxytocin infusion should be useful for the uterus relief. A period of uterine relaxation also allows to recover the contraction strength for the delivery, probably due to the reduction of lactic acid in the myometrium and to an increase of O(2) saturation. The actual management of dysfunctional labor with oxytocin may cause an increase of an inefficient uterine contraction if patient has a background of lactate acidosis [21]. Several studies observed that a PSSL could be associated to side effects like post-partum hemorrhage [14]. In our study, no collateral effects were observed, probably due to the cessation of maternal pushing and/or the cessation of oxytocin infusion. This is the first study correlated with the TPU that investigates the possibility of a SD in the PSSL. A limit of our work is represented by the population sample size even if results are SS. Further studies are needed to assess this hypothesis; however, it appears that the diagnosis of upward direction is useful in clinical management of the arrested second stage of labor. In contrast, it is not that clear
whether the diagnoses of horizontal or downward direction can have an impact in clinical management.
Acknowledgements The authors wish to thank Laura Bergamasco, Full Professor at the Department of Physics at Turin University, for the precious work regarding statistical analysis, and Dr. Lorella Vesentini for the enthusiastic cooperation regarding drawing Figures 1 and 2.
Declaration of interest The authors report no declarations of interest.
References 1. American College of Obstetricians and Gynecologists. Operative vaginal delivery. 17. Washington, DC: The College; 2000. 2. Yvonne W, Cheng MD, Linda M, et al. How long is too long: does a prolonged second stage of labor in nulliparous women affect maternal and neonatal outcomes? Am J Obstet Gynecol 2004;191: 933–8. 3. Saunders NG, Paterson CM, Wardworth J. Neonatal and maternal morbidity in relation to the length of the second stage of labour. BJOG 1992;99:381–5. 4. Yli BM, Kro GA, Rasmussen S, et al. How does the duration of active pushing in labor affect neonatal outcomes? J Perinat Med 2011;40:171–8. 5. Murphy DJ, Macleod M, Bahl R, Strachan B. A cohort study of maternal and neonatal morbidity in relation to use of sequential instruments at operative vaginal delivery. Eur J Obstet Gynecol Reprod Biol 2011;156:41–5. 6. Dietz HP, Lanzarone V. Measuring engagement of the fetal head: validity and reproducibility of a new ultrasound technique. Ultrasound Obstet Gynecol 2005;25:165–8. 7. Lu MC, Muthengi E, Wakeel F, et al. Prolonged second stage of labor and postpartum hemorrhage. J Matern Fetal Neonatal Med 2009;22:227–32. 8. Kalache KD, Du¨ckelmann AM, Michaelis SAM, et al. Transperineal ultrasound imaging in prolonged second stage of labor with occipitoanterior presenting fetuses: how well does the ‘angle of progression’ predict the mode of delivery? Ultrasound Obstet Gynecol 2009;33:326–30. 9. Barbera A, Pombar X, Perugino G, et al. A new method to assess fetal head descent in labor with transperineal ultrasound. Ultrasound Obstet Gynecol 2009;33:313–9. 10. Henrich W, Dudenhausen J, Fuchs I, et al. Intrapartum translabial ultrasound (ITU): sonographic landmarks and correlation with successful vacuum extraction. Ultrasound Obstet Gynecol 2006;28: 753–60. 11. Sherer DM, Miodovnik M, Bradley KS, Langer O. Intrapartum fetal head position II: comparison between transvaginal digital examination and transabdominal ultrasound assessment during the second stage of labor. Ultrasound Obstet Gynecol 2002;19:264–8.
US in labor to reduce the operative delivery rate?
DOI: 10.3109/14767058.2013.868430
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