Main Findings
Pregnancy are known to be the main risk factors for Candida
albicans infection (15). In vitro experiments confirmed that
estrogen-pretreated mice with the same concentration of
progesterone(10-6M) in late pregnancy could strongly
inhibit the anti-Candida activity of neutrophils, which led to an
increase in the susceptibility of pregnant women to VVC(16). A study on
the vagina of castrated rats showed that compared with rats not treated
with estrogen, the vaginal microflora was more diverse in rats treated
with estrogen and colonized with vaginal yeast(17), indicating that
hormone status was involved in the characteristics of vaginal flora
under Candida infection, which may also be the cause of mixed fungal and
bacterial infection.
Diabetes is known to be the main risk factor for C.albicansinfection(15, 18). In 2018, Xinhong et al. (19) compared 186 gestational
diabetes (GDM) patients with 200 healthy pregnant women and found that
GDM not only increase the incidence of VVC, but also increase the
incidence of BV+VVC mixed infection. Our study found that a positive
glucose tolerance test during pregnancy is a risk factor leading to
mixed VVC+BV infection, which is consistent with the above studies.
However, another study did not find a difference in the incidence of BV
and VVC between the diabetes group and the control group(20). Perhaps
this study analyzed the difference in vaginitis during the first
trimester.
In 2007, Britton et al.(20) studied the risk factors of BV in pregnancy
and found that sexual intercourse during early pregnancy was associated
with an increased risk of BV in the second trimester. Our research
showed that sexual intercourse during pregnancy is a risk factor leading
to VVC+BV in late pregnancy, which may be related to the fact that
sexual intercourse itself has a greater interference effect on normal
vaginal flora(21). Immunity during pregnancy is lower than during
non-pregnancy, and the ability to recover the normal flora after sexual
intercourse is reduced, which leads to the occurrence of mixed
vaginitis.
Patients with mixed vaginitis have complex genital symptoms and
signs(22). Our team previously analyzed the clinical symptoms, signs and
laboratory characteristics of patients with AV mixed vaginitis(22).
Similar to this research, our research found that patients with VVC+AV
often had genital itching. Furthermore, our research also found that
compared with patients with AV, the genital burning, redness and edema
vulva and vaginal erythema were more obvious in patients with VVC+AV;
compared with patients with VVC, the genital burning, vaginal erythema,
and yellow discharge in patients with VVC+AV were more obvious; and
compared with patients with VVC, pH > 4.5 and WBC
> 10/hpf were significantly higher in patients with VVC+AV.
Similar to this research, our research also found that compared with
patients with BV, yellow vaginal discharge in patients with AV+BV was
more significant. However, our literature also found that compared with
patients with BV, pH > 4.5 and WBC > 10/hpf
were significantly higher in patients with AV+BV. Therefore, our
research believes that mixed vaginitis has complex symptoms and signs,
which is difficult to distinguish from the corresponding single
vaginitis, and laboratory examination is the most effective method to
distinguish mixed vaginitis from single vaginitis.
Mixed vaginitis is associated with adverse pregnancy outcomes .
In 2018, Cha Han et al.(5) studied the pregnancy outcomes of pregnant
women with AV and found that AV was associated with a high incidence of
PROM. Our research found that the incidence of PROM increases in
patients with VVC+AV compared with patients with VVC, which may be
caused by AV. In 2016, Dingens et al.(23) studied the relationship
between BV and adverse pregnancy outcomes in 12340 matched pregnant
women and their newborns in Washington State. This research found that
the incidence of neonatal ICU admission of BV-positive pregnant women
increased. Our research finds that
compared with patients with BV, the incidence of NICU admission is
higher in patients with VVC+BV, which may be related to the increased
incidence of NICU admission caused by VVC mixed vaginitis in the case of
BV. Abnormal vaginal flora during pregnancy is associated with puerperal
infection(19). In 2019, Wei Dai et al. (24)conducted a research on 380
women in late pregnancy and found that the puerperium infection was
related to the colonization of Group B streptococcus (GBS) (AV pathogen)
during pregnancy. Similar to our study, the VVC+AV mixed infection has
an increased incidence of puerperal infection compared with the VVC
group and the normal group, which may be related to AV.
Analysis of the reason may be
related to intrauterine infection caused by ascending infection of lower
genital tract, activating intrauterine inflammation pathways, further
causing puerperal infections(25-27).