Failed TOLAC:
Table S1 presents selected maternal and delivery characteristics and outcomes of parturients attempting TOL following 2 CD according to the actual mode of delivery. Parturients with failed TOLAC (67/485) were of lower gravidity and parity order with higher rates of multifetal gestation. Rates of macrosomia did not differ between the groups. All parturients planning TOLAC with multifetal gestation failed (4/4). Rates of composite adverse maternal and neonatal outcomes were significantly higher among those who had failed TOLAC (11.9% vs. 5.3% and 29.9% vs 2.4%, respectively, p<0.01 for both). A multivariate analysis controlling for parity, diabetes, hypertensive disorder of pregnancy and epidural usage had demonstrated an independent association between failed TOLAC and composite adverse maternal outcome (aOR 2.55, 95% CI 1.05-6.22). An additional multivariate analysis controlling for diabetes, hypertensive disorder of pregnancy, gestational age at birth and neonatal birth weight demonstrated an independent association between failed TOLAC and composite adverse neonatal outcome (aOR 7.05, 95% CI 2.60-19.05). When assessing factors associated with failed TOLAC, diabetes and hypertensive disorders of pregnancy were found positively associated (aOR 3.13, 95% CI 1.30-7.70 an aOR 8.45, 95% CI 2.09-34.12, respectively) while epidural was found to be negatively associated (aOR 0.42, 95% CI 0.24-0.75); an association to parity and gravidity was not demonstrated.
Discussion In this retrospective cohort study, maternal and neonatal outcomes were compared between parturients with a history of previous two CD attempting TOL versus those who had scheduled a third elective CD. Seventeen percent of parturients with two previous CD met our protocol criteria and expressed their preference for TOLAC. VBAC rates were overall high (86%). Parturients attempting TOL had higher rates of uterine rupture with an overall rate of 0.6%; otherwise maternal outcomes were comparable. Failed TOLAC was found independently associated with composite adverse neonatal outcome, in addition to diabetes mellitus and hypertensive disorders of pregnancy.
Previous studies have described an array of VBAC rates following two CD, ranging between 66-75% 10,14–16, with a pooled rate of 71%17. Our VBAC success rates (86%) are higher than those described in the literature. It is possible that this is related to our department’s protocol which requires previous vaginal delivery and spontaneous onset of labor which were proven to be the best predictors for VBAC.18
Previous studies were inconclusive regarding maternal results associated with TOLAC. Some studies15 indicated a two-fold increase in the risk of composite maternal morbidity, including uterine rupture, bladder injury, or other major operative injuries, while others17 demonstrated comparable outcomes between the groups. Our study demonstrated a non-significant lower rate of blood transfusion, re-laparotomy, and hysterectomy in the TOLAC group. This result was demonstrated in previous studies7,15,17 and most probably reflects the increased risk inherent to multiple CD19,20. Previous studies 15149demonstrated rates of uterine rupture following two or more previous CD ranging between 0.8%-3.7% and concluded that uterine rupture was significantly more common in those attempting TOLAC in comparison to those who chose repeat elective CD. On the other hand, one16 retrospective study did not demonstrate a significant difference in uterine rupture. A meta-analysis17 determined a pooled risk of 1.36% for a uterine rupture in TOLAC after two CD. Our data indicated an absolute risk of 0.6% for uterine rupture when attempting TOL which is significantly higher when compared to an elective CD (0.6% vs. 0.1%, p=0.04) but it is to our knowledge, the lowest rate described in literature and does not differ significantly from the risk described for TOL following one CD 21. The relatively lower rates of uterine rupture along with the remarkable high VBAC rate might be attributed to several factors related to our departmental protocol: 1. In our institution, labor was not induced nor augmented, unlike previous studies in which 65% of parturients were induced15 2. In our study only parturients with prior two low segment transverse incisions were approved for TOL, unlike previous studies that included parturients with unknown scars and had higher rates of uterine rupture which reached 5.4%10,14. 3. Previous VD is a mandatory criteria in our institution and was proven to be not only one of the best predictors for a VBAC22,23 but also a protective factor for uterine rupture 14,15.
Rates of composite adverse neonatal outcomes were significantly higher among those who had an elective repeat CD. This difference could have been explained by the difference in gestational age and higher NICU admission rates in the parturients having elective repeat CD24. However, when controlling for gestational age and other potential confounders, an independent association to an elective repeat CD was not demonstrated. Similar to our results, other studies4 showed no significant differences when comparing NICU admission and term neonatal death14,17. Not surprisingly, the rate of the composite adverse neonatal outcome was significantly higher among those who had failed TOLAC. This finding correlates with other studies that demonstrated poor 1-minute Apgar scores that were four times more common among those with a failed TOLAC.16
The ability to predict successful TOLAC is of great importance as maternal and neonatal morbidity is greater among those who fail TOLAC and require a repeat CD in labor. Our results indicated that failed TOLAC was associate with diabetes and hypertensive disorders, both of which were similarly identified as risk factors for failed TOLAC in other studies. 4 In our study all parturients attempting TOLAC with multifetal gestation (4/4) failed. Due to our relatively small sample size and the fact that previous studies did not demonstrate an association between multifetal gestation and failed TOLAC, we believe that further studies are needed in order to better examine the association between the two18. Macrosomia was previous described as a predictor of a failed TOLAC26. Nevertheless, in our study rates of macrosomia were significantly higher among those attempting TOLAC while rates of macrosomia did not differ between those who achieved VBAC or failed TOLAC. Comparable to findings in a previous study 27 our results raise the question of the role of macrosomia in failed TOLAC among those parturients who previously delivered vaginally. Further studies are needed in order to address this issue in groups of parturients attempting TOLAC with one previous VD.
This study holds several notable strengths: This is a large-scale population study comprising more than a third of the births in the area studied and 10% of all national births; therefore, suitable for generalization. In addition, our database is validated at real-time, which assists in eliminating potential information bias. All costs of antenatal care, birth, postpartum care for mother and child are uniformly covered by the National Health Insurance for the entire study period. Moreover, all mother-child data included were from one hospital with no transfers to other facilities. Both factors alleviate a potential selection bias; Lastly, the adherence to our strict department protocol permitted us to examine the results of a designated, relatively low-risk group of patients. Despite imposing a strict study inclusion criterion, a fair number of parturients were found eligible and attempted a relatively safe TOL.
Our study is not without limitations: A possible limitation may be due to our retrospective design and its’ inherent fault. We were unable to identify and conduct a subgroup analysis of parturients who intended an elective repeat CD and presented in labor and hence underwent urgent surgery. Furthermore, our population has specific characteristics, particularly the motivation for large families. This may preclude in part the ability to generalize our study’s results. However, we believe that most of the parturients who are interested in TOLAC following two previous CD share some characteristics in common, which may set a ground for potential partial generalization. We also recognize that our data collection process did not provide information regarding potential risk factors associated with uterine rupture, such as prior uterine closure technique, the number of previous VBAC, and an unknown number of classical uterine scars in the elective repeat CD group. Nonetheless, we did attempt to control for most recognized factors and excluded all identified parturients who did not meet the ACOG criteria for TOLAC28.
Conclusion : parturients with a history of two CD attempting TOLAC complying to a strict department protocol, have overall comparable and favorable maternal and neonatal outcomes. Therefore, TOL is a reasonable alternative to an elective repeated third CD. Diabetes and hypertensive disorder are associated with failed TOLAC; obstetricians should be aware of these findings when providing consultation.
Acknowledgements: We thank Pnina Mor, PhD for the critical appraisal of the manuscript and English editing.
Declaration of interest : The authors declare that they have nothing to disclose and that they have no financial or non-financial conflict of interest.
Disclosure of interests: The authors report no conflict of interest.
Funding/Support: This study was not funded.
Financial Disclosures: No financial disclosures.
Contribution to authorship: R Rotem: Protocol development, Data collection and management, Data analysis, Manuscript writing/editing.A Hirsch: Protocol development, Data collection and management, Data analysis, Manuscript writing/editing. HY Sela: Protocol development,Manuscript writing/editing.A Samueloff: Data collection and management, Manuscript writing/editingS Grisaru-Granovsky : Protocol development, Manuscript writing/editing.M Rottenstreich: Protocol development, Data collection and management, Data analysis, Manuscript writing/editing.
Ethical approval: The study was approved by the local Institutional Review Board of SZMC (IRB: 001-20-SZMC, 16.12.2109). As the study was based on patient records, no informed consent was needed.
Figure legend :
Figure 1: Flow chart of the study group.
References:
1. Boerma T, Ronsmans C, Melesse DY, et al. Global epidemiology of use of and disparities in caesarean sections. Lancet . 2018;392(10155):1341-1348. doi:10.1016/S0140-6736(18)31928-7
2. Zhang J, Troendle J, Reddy UM, et al. Contemporary cesarean delivery practice in the United States. Am J Obstet Gynecol . 2010;203(4):326.e1-326.e10. doi:10.1016/j.ajog.2010.06.058
3. Silver RM, Landon MB, Rouse DJ, et al. Repeat Cesarean Deliveries. 2006;107(6):1226-1232.
4. Sandall J, Tribe RM, Avery L, et al. Optimising caesarean section use 2 Short-term and long-term effects of caesarean section on the health of women and children. Lancet . 2018;392(10155):1349-1357. doi:10.1016/S0140-6736(18)31930-5
5. Trojano G, Damiani GR, Olivieri C, et al. VBAC: antenatal predictors of success. Acta Biomed . 2019;90(3):300-309. doi:10.23750/abm.v90i3.7623
6. No R, Practice O. Vaginal delivery after a previous cesarean birth.Int J Gynecol Obstet . 1995;48(1):127-129. doi:10.1016/0020-7292(95)90280-5
7. Chattopadhyay SK, Sherbeeni MM, Anokute CC. Planned vaginal delivery after two previous caesarean sections. BJOG An Int J Obstet Gynaecol . 1994;101(6):498-500. doi:10.1111/j.1471-0528.1994.tb13149.x
8. Granovsky-Grisaru S, Shaya M, Diamant YZ. The management of labor in women with more than one uterine scar: Is a repeat cesarean section really the only “Safe” option? J Perinat Med . 1994;22(1):13-17. doi:10.1515/jpme.1994.22.1.13
9. Caughey AB, Shipp TD, Repke JT, Zelop CM, Cohen A, Lieberman E. Rate of uterine rupture during a trial of labor in women with one or two prior cesarean deliveries. Am J Obstet Gynecol . 1999;181(4):872-876. doi:10.1016/S0002-9378(99)70317-0
10. Miller DA, Diaz FG, Paul RH. Vaginal birth after cesarean: A 10-year experience. Obstet Gynecol . 1994;84(2):255-258.
11. Birth V, Cesarean A. ACOG Practice Bulletin No. 205: Vaginal Birth After Cesarean Delivery. Obstet Gynecol . 2019;133(2):e110-e127. doi:10.1097/AOG.0000000000003078
12. Patel H, Patel P, Shah DK. Relaparotomy in general surgery department of tertiary care hospital of Western India. Int Surg J . 2016;4(1):344. doi:10.18203/2349-2902.isj20164467
13. Prevention and Management of Postpartum Haemorrhage: Green-top Guideline No. 52. BJOG . 2017;124(5):e106-e149. doi:10.1111/1471-0528.14178
14. Landon MB, Spong CY, Thom E, et al. Risk of uterine rupture with a trial of labor in women with multiple and single prior cesarean delivery. Obstet Gynecol . 2006;108(1):12-20. doi:10.1097/01.AOG.0000224694.32531.f3
15. Macones GA, Cahill A, Pare E, et al. Obstetric outcomes in women with two prior cesarean deliveries: Is vaginal birth after cesarean delivery a viable option? Am J Obstet Gynecol . 2005;192(4):1223-1228. doi:10.1016/j.ajog.2004.12.082
16. Asakura H, Myers SA. More than one previous cesarean delivery: a 5-year experience with 435 patients. Obstet Gynecol . 1995;85(6):924-929. doi:10.1016/0029-7844(95)00078-6
17. Tahseen S, Griffiths M. Vaginal birth after two caesarean sections (VBAC-2) - A systematic review with meta-analysis of success rate and adverse outcomes of VBAC-2 versus VBAC-1 and repeat (third) caesarean sections. BJOG An Int J Obstet Gynaecol . 2010;117(1):5-19. doi:10.1111/j.1471-0528.2009.02351.x
18. Landon MB, Leindecker S, Spong CY, et al. The MFMU Cesarean Registry: factors affecting the success of trial of labor after previous cesarean delivery. Am J Obstet Gynecol . 2005;193(3 Pt 2):1016-1023. doi:10.1016/j.ajog.2005.05.066
19. Silver RM, Landon MB, Rouse DJ, et al. Maternal morbidity associated with multiple repeat cesarean deliveries. Obs Gynecol . 2006;107(6):1226-1232.
20. Cook JR, Jarvis S, Knight M, Dhanjal MK. Multiple repeat caesarean section in the UK: Incidence and consequences to mother and child. A national, prospective, cohort study. BJOG An Int J Obstet Gynaecol . 2013;120(1):85-91. doi:10.1111/1471-0528.12010
21. Landon MB, Hauth JC, Leveno KJ, et al. Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery.N Engl J Med . 2004;351(25):2581-2589. doi:10.1056/NEJMoa040405
22. Caughey AB, Shipp TD, Repke JT, Zelop C, Cohen A, Lieherman E. Trial of labor after cesarean delivery: The effect of previous vaginal delivery. In: American Journal of Obstetrics and Gynecology . Vol 179. Mosby Inc.; 1998:938-941. doi:10.1016/S0002-9378(98)70192-9
23. Mercer BM, Gilbert S, Landon MB, et al. Labor Outcomes With Increasing Number of Prior Vaginal Births After Cesarean Delivery.Obstet Gynecol . 2008;111(2, Part 1):285-291. doi:10.1097/AOG.0b013e31816102b9
24. Jensen JR, White WM, Coddington CC. Maternal and neonatal complications of elective early-term deliveries. Mayo Clin Proc . 2013;88(11):1312-1317. doi:10.1016/j.mayocp.2013.07.009
25. Wu Y, Kataria Y, Wang Z, Ming WK, Ellervik C. Factors associated with successful vaginal birth after a cesarean section: A systematic review and meta-analysis. BMC Pregnancy Childbirth . 2019;19(1):1-12. doi:10.1186/s12884-019-2517-y
26. Jastrow N, Roberge S, Gauthier RJ, et al. Effect of birth weight on adverse obstetric outcomes in vaginal birth after cesarean delivery.Obstet Gynecol . 2010;115(2 PART 1):338-343. doi:10.1097/AOG.0b013e3181c915da
27. Elkousy MA, Sammel M, Stevens E, Peipert JF, Macones G. The effect of birth weight on vaginal birth after cesarean delivery success rates.Am J Obstet Gynecol . 2003;188(3):824-830. doi:10.1067/mob.2003.186
28. ACOG. Clinical Management Guidelines for Obstetrician – Gynecologists. Obstet Gynecol . 2019;133(76):168-186.