Introduction
Cesarean delivery (CD) is one of the most common surgeries worldwide,
performed on one in four pregnant women in the UK (according to the NHS
website) and up to four in five women in other regions of the
world.1 The rate of subsequent vaginal birth after
Cesarean section (VBAC) is low, and estimated to be 13.3% in the United
States,2 and only 52.2 percent will attempt VBAC for
their second birth in the UK.3 The implications of
repeat CD on morbidity are profound and include higher rates of blood
transfusions, surgical injuries and hysterectomies, with increased rates
of complications as the number of CD increases.4,5Therefore, many healthcare organizations try to increase VBAC rates.
When consulting a woman regarding the mode of delivery, the risks and
benefits of trial of labour after Cesarean (TOLAC) should be discussed,
as well.6 Each woman should be advised according to
her own obstetric and demographic characteristics, as well as her
personal risk-factors for uterine rupture.7 Known
risk-factors, such as previous arrest of descent, vertical uterine scar,
etc. are well-established but infection of surgical site in the first CD
is a possible risk-factor that has not been investigated in depth. The
few studies that have been published are small and most did not isolate
the type of infection as an independent risk factor.8Currently, previous peripartum infections are not included into
consultations regarding the preferred mode of delivery after a CD.
Peripartum infections may influence scar tissue healing and consequently
affect uterine scar strength and ability to remain intact during
subsequent pregnancies and deliveries. They include chorioamnionitis
during labour, postpartum endometritis and other surgical site
infections. Surgical site infection tends to occur within 30 days of the
operation9 and may affect superficial or deep tissues.
Pathogens commonly associated with obstetrical infections are
Gram-negative bacilli, enterococci, Group B streptococci and
anaerobes.10
It is well-established that surgical scar infection is a risk-factor for
impaired healing.11 The pathogens interfere with
leukocyte function and angiogenesis. Free radicals and cytotoxic enzymes
are released from neutrophils,12,13 which may
interfere with the healing process and leave the scar weaker and more
vulnerable. Although it is not commonly considered a risk-factor for
uterine rupture during labour, a surgical scar with previous surgical
site infection (SSI) may have a higher tendency to rupture during a
subsequent trial of labour.
The objective of this study was to investigate whether peripartum
infection in the first CD is an independent risk-factor for uterine
rupture in a subsequent delivery.