Methods:
In this retrospective cohort study all parturients at the Shaare Zedek
Medical Center (SZMC) with a history of two previous CD between August
2005 and November 2019, were enrolled. We included parturients between
24-42 weeks of gestations who had two prior CDs and subsequently had
vaginal vertex births and parturients who chose to have a repeat
elective CD. Excluded from the study were parturients with non-vertex
presentation, placenta previa, placenta accrete, mullerian uterine
anomalies, multifetal gestation other than twins and parturients without
at least one previous vaginal delivery. A comparison was made between
those who attempted TOLAC and those who were scheduled for an elective
repeat CD.
In general, our department’s standard recommendation following previous
two CD is to undergo an elective repeat CD. However, TOLAC is discussed
with those parturients who express interest in attempting labor after
CD. TOLAC is discussed only if all the following criteria are validated.
The criteria are as follows: 1. The parturient explicitly expresses her
request for TOLAC and comprehends the potential risks, benefits, and
alternatives. 2. The parturient had a previous vaginal delivery (VD),
either before, between or after the second CD. 3. Both previous uterine
incisions were low segment transverse, there were no extensions or
severe adhesions. 4. Fetal estimated weight is <4000 grams. 5.
Vertex presentation. Additionally, the onset of labor must be
spontaneous, we do not induce or augment labor in parturient with 2
previous CD.
SZMC’s medical record database on all labor and deliveries is updated in
real time during labor and delivery by attending healthcare
professionals and audited periodically by trained technical personnel to
ensure validity of the data. Over 95% of Israeli citizens’ medical care
is covered by the Israeli National Health Plan hence continuity of care
is granted for long periods of time for most of the patients. Maternal
and neonatal records were reviewed and retrieved for relevant data,
information was coded and identifiable, and personal information for
each patient was protected by anonymization prior to analysis.
Definitions: The terms used were defined as the following: Uterine
rupture - complete uterine scar ruptures, i.e. involving the occurrence
of a full-thickness defect with direct connection between peritoneal
space and the uterine cavity. Diagnosis was made by an attending
physician during an explorative laparotomy. Re-laparotomy –additional abdominal operation performed during hospitalization for
delivery12 Postpartum hemorrhage (PPH): Was
defined using one of the two following definitions: 1. Estimated blood
loss of over 500 ml in vaginal delivery (VD) and over 1000 ml in CD13 (In SZMC pads are weighted following VD, but in
some cases when pads or weighting is not feasible blood loss is
estimated subjectively by the midwife/obstetrician); 2. the transfusion
of blood products and/or hemoglobin drop> 4 gr/dL.Prolonged hospitalization : > 5 days for
vaginal deliveries and > 7 days for cesarean
deliveries.
Primary outcome was defined as a composite adverse
maternal outcome : one or more of the following: PPH, hemoglobin
drop> 4 gr/dL, blood products transfusion, intensive
care unit (ICU) admission.Secondary outcomes were defined as follows: 1. Composite adverse neonatal outcome : a composite outcome of one or
more of the following: 5-min Apgar score < 7, neonatal
asphyxia, neonatal intensive care unit (NICU) admission, and the need
for mechanical ventilation.
2. Composite adverse maternal and neonatal outcome s among the
group of parturients attempting TOLAC. We compared those who achieved
VBAC and those whose attempt at labor was aborted and necessitated in
labor CD
Statistical analysis : An initial univariate analysis was carried
out, categorical variables were presented as a percentage and compared
using Chi square and Fisher’s exact test as appropriate. Continuous
variables presentation was according to each variable distribution,
while normal distributed variables were presented as a mean and standard
deviation, those displaying non-normal distribution were presented as
median with interquartile range. A comparison was made using Student’s
t-test and Mann Whitney test, accordingly. All analyses were two sided
and a p value < 0.05 was considered statistically
significant.
Data analysis was conducted according to the group category to which the
parturient was initially categorized corresponding to her original
request. For instance, if a parturient originally requested an elective
CD and presented in active labor, resulting in an emergency CD, she
remained in the analysis of the planned elective CD group. However, all
parturients analyzed in the TOLAC group attempted TOL even if the result
was CD. A multivariate analysis using a binary logistic regression model
was used in order to account for the independent association between
composite adverse neonatal outcomes, infusion of blood products and
TOLAC versus elective CD after 2 CDs. Adjusted Odds Ratios (aOR) and
95% confidence intervals (CI) were computed.
A sub-group analysis comparing in-labor CD (=failed TOLAC) versus
successful VBAC was conducted. A univariate analysis was followed by a
multivariate analysis in order to examine independent factors associated
with TOLAC failure.
Data analysis was carried out using SPSS software (version 23
statistical package; IBM, Armonk, NY). The study was approved by the
local institutional ethics committee in accordance with the principles
of the Declaration of Helsinki (IRB: 001-20-SZMC).