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.