Pyelonephritis in pregnancy
After anaemia, pyelonephritis has been
identified as the second most common medical
complication of pregnancy, affecting 1-2%
of pregnant women with illness, and usually
manifesting during the second or third
trimesters (Sharma and Thapa 2007, Jolley and
Wing 2010). Hormonal and chemical changes
during pregnancy predispose women to upper
urinary tract infections and pyelonephritis
(Ramakrishnan and Scheid 2005, Lohr et al
2012). Widening of the renal pelvis and ureters
may lead to pooling of urine. In addition,
progesterone decreases peristalsis in the ureter
and increases the capacity of the bladder, leading
to reduced urine excretion rates. In the later
stages of pregnancy, the enlarged uterus will
displace the bladder to some extent, contributing
to urine stasis and potential development of
infection (Fulop and Mena 2012).
Up to 20% of pregnant women treated
successfully for pyelonephritis during
pregnancy will experience recurrence of illness
before or shortly after giving birth (Jolley and
Wing 2010). Although there is little evidence
to demonstrate that pyelonephritis during
pregnancy causes premature delivery or low
birth weight among infants (Sharma and
Thapa 2007, Jolley and Wing 2010), there
may be significant consequences of the illness
for the mother and fetus during pregnancy,
including (Jolley and Wing 2010, Fulop and
Mena 2012):
Anaemia (reported in approximately 25%
of pregnant women with pyelonephritis).
Disseminated intravascular coagulation.
Sepsis and shock.
Adult respiratory distress syndrome
(reported in 1-8% of cases, with symptoms
ranging from comparatively mild to life
threatening, which means they require
ventilatory support).
Historically, pregnant women with
pyelonephritis were routinely admitted to
hospital to enable effective screening and
management of potential complications.
However, there is little evidence to support this
practice and many otherwise healthy pregnant