Placentitis is an
inflammation
Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...
of the
placenta
The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...
. The main forms of placentitis are:
*Villitis, inflammation of
chorionic villi
Chorionic villi are Wiktionary:villus, villi that sprout from the chorion to provide maximal contact area with maternal blood.
They are an essential element in pregnancy from a histology, histomorphologic perspective, and are, by definition, a pr ...
.
*Intervillositis, inflammation of the
intervillous space.
It may be caused by
vertically transmitted infection
A vertically transmitted infection is an infection caused by pathogenic bacteria or viruses that use mother-to-child transmission, that is, transmission directly from the mother to an embryo, fetus, or baby during pregnancy or childbirth. It ...
s.
Because of the close proximity, placentitis often occurs simultaneously as
funisitis
Funisitis is inflammation of the connective tissue of the umbilical cord that occurs with chorioamnionitis.
It involves only the external cord surface and Wharton's jelly. It has no involvement of the vessels. It does not involve the umbilical st ...
(inflammation of the
umbilical cord
In Placentalia, placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord i ...
) and
chorioamnionitis (inflammation of the
fetal membranes
The fetal membranes are the four extraembryonic membranes, associated with the developing embryo, and fetus in humans and other mammals. They are the amnion, chorion, allantois, and yolk sac. The amnion and the chorion are the chorioamniotic ...
).
Chronic lymphocytic placental inflammation occurs in 5% to 15% of pregnancies, and are generally not associated with documented infection.
Villitis of unknown etiology
''Villitis of unknown etiology'' (''VUE''), also known as ''chronic villitis'', is a placental injury. VUE is an
inflammatory condition involving the
chorionic villi
Chorionic villi are Wiktionary:villus, villi that sprout from the chorion to provide maximal contact area with maternal blood.
They are an essential element in pregnancy from a histology, histomorphologic perspective, and are, by definition, a pr ...
(placental villi). VUE is a recurrent condition and can be associated with
intrauterine growth restriction (IUGR). IUGR involves the poor growth of the foetus,
stillbirth
Stillbirth is typically defined as fetus, fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without vital signs, signs of life. A stillbirth can often result in the feeling of guilt (emotio ...
,
miscarriage
Miscarriage, also known in medical terms as a spontaneous abortion, is an end to pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can fetal viability, survive independently. Miscarriage before 6 weeks ...
, and
premature delivery.
VUE recurs in about 1/3 of subsequent pregnancies.
VUE is a common lesion characterised by inflammation in the placental chorionic villi. VUE is also characterised by the transfer of maternal lymphocytes across the
placenta
The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...
.
VUE is diagnosed in 7–10% placentas in pregnancies. Roughly 80% of the VUE cases are in term placentas (greater than 37 weeks of pregnancy). A case of VUE in a placenta less than 32 weeks old should be screened for infectious villitis.
Chronic histiocytic intervillositis
''Chronic Histiocytic Intervillositis'' (''CHI'' or ''CHIV'') also known as Chronic Intervillositis of Unknown (A)etiology (CIUE) and Massive Chronic Intervillositis (MCI) is defined as a diffuse infiltration of
mononuclear cells (histiocytes, lymphocytes, monocytes) of maternal origin into the
intervillous space within the
placenta
The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...
. It often results in severe
intrauterine growth restriction which can lead to
miscarriage
Miscarriage, also known in medical terms as a spontaneous abortion, is an end to pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can fetal viability, survive independently. Miscarriage before 6 weeks ...
or
stillbirth
Stillbirth is typically defined as fetus, fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without vital signs, signs of life. A stillbirth can often result in the feeling of guilt (emotio ...
. Overall perinatal mortality rate is high: 41%
to 77%.
Recurrence rate is also high: 67%
to 100%.
See also
*
Chorioamnionitis
References
{{reflist
External links
CHI SupportCHI Facebook Support Group
Placentation disorders