Trial of labor after Cesarean delivery for estimated large for
gestational age fetuses: a retrospective cohort study
Abstract
Objective: Estimated fetal weight, large for gestational age (eLGA)
(≥90th percentile) may be associated with failed trial of labor after
Cesarean (TOLAC), like fetal macrosomia. The aim of this study was to
evaluate obstetrical outcome and safety of TOLAC, for women with eLGA.
Design: A retrospective cohort study. Setting: a single large tertiary
care center. Population or Sample: all women with singleton pregnancy,
gestational age ≥ 37weeks, admitted for TOLAC between 2012 and 2017.
Methods: Women with eLGA were compared to women with EFW <
90th percentile. Main outcome measures: the rate of successful vaginal
delivery, adverse obstetrical outcomes. Results: 1949 women met
inclusion criteria, including78 (4%) eLGA and 1871 (96%) controls.
Study group were older (35 vs. 33 year; p=0.004), with higher Body Mass
Index (30.9 vs. 27.5 kg/m2; p=0.001) and higher gravidity (4 vs. 3;
p=0.001) compared to the controls. Median fetal weight was [3887g (IQR
3718-4073) vs. 3275g (IQR 2995-3545); p=0.001 in the study vs. controls
respectively]. 55 (70.5%) women in the study group had successful
vaginal delivery compared to 1506 (80.5%) women in the control (p=
0.03). The rate of obstetrical complications, including: scar
dehiscence, uterine rupture, 3rd /4th degree perineal tear or shoulder
dystocia were comparable. The rate of post-partum hemorrhage was
increased in the study group compared to controls (7.7% vs.1.7%;
p=0.001). Conclusion: TOLAC for eLGA fetuses can be considered as safe,
however, lower successful VBAC rates and increased PPH rate may be
expected.