BLEEDING DURING • The process of shock due to blood loss is
shown:
PREGNANCY
Friday, 21 February 2025
3:23 pm
BLEEDING DURING PREGNANCY
• Vaginal bleeding during pregnancy is always
a deviation from the normal, is always
potentially serious, may occur at any point
during pregnancy, and is always frightening.
It must always be carefully investigated
because it can impair both the outcome of
the pregnancy and the woman’s health or
life.
• The primary causes of bleeding during
pregnancy:
• Because the uterus is a nonessential body
organ, danger to the fetal blood supply
occurs when a woman’s body begins to
decrease blood flow to peripheral organs
(although the increased blood volume of
pregnancy allows more than normal blood
loss before hypovolemic shock processes
begin).
• Signs of hypovolemic shock occur when
10% of blood volume, or approximately 2
units of blood (1L), have been lost; fetal
distress occurs when 25% of blood
volume is lost
When a person is in shock, their body
activates a survival response to maintain
• Although vaginal bleeding may be innocent, blood flow to the most critical organs
any degree of this during pregnancy is a (brain, heart, lungs, etc.) that are
potential emergency because it may mean essential for life. This happens because
the placenta has loosened and cut off shock usually causes low blood
nourishment to the fetus. Also, the amount pressure or poor circulation.
of blood visualized may be only a fraction of 1. Vasoconstriction (narrowing of blood
the blood actually being lost because an vessels) occurs in non-essential areas, like
undilated cervix and intact membranes the skin, arms, and legs, to redirect blood
contain blood within the uterus. flow to vital organs.
• A woman with any degree of bleeding, 2. This reduced blood flow to the skin makes it
therefore, needs to be evaluated for the feel cold and look pale or clammy.
possibility she is experiencing a significant It's the body's way of prioritizing oxygen
blood loss or is developing hypovolemic and nutrients to organs that are crucial
shock. for survival during emergencies like
ANGELES, MICAELLA N.
, shock. This is why cold, clammy skin is a miscarriage or is termed a premature or
key symptom of shock. immature birth (Gilbert, 2011).
• Spontaneous miscarriage occurs in 15% to
30% of all pregnancies and arises from
natural causes (McNair & Altman, 2011).
• A miscarriage is an early miscarriage if it
occurs before week 16 (4 months) of
pregnancy and a late miscarriage if it
occurs between weeks 16 and 24.
• For the first 6 weeks of pregnancy, the
developing placenta is tentatively attached
to the decidua of the uterus; during weeks 6
to 12, it is moderately attached. After week
12, the attachment is penetrating and deep.
Because of these degrees of attachment
achieved at different weeks of pregnancy, it
is important to attempt to establish the week
of the pregnancy at which bleeding has
• Because “normal” blood pressure varies become apparent.
from woman to woman, it is important to • Bleeding before week 6 is rarely severe;
know the baseline blood pressure for a bleeding after week 12 can be profuse
pregnant woman when evaluating for because the placenta is implanted so
hypovolemic shock. deeply. Fortunately, at this time, with such
deep placental implantation, the fetus tends
to be expelled as in natural childbirth before
the placenta separates. Uterine
contractions, however, then help to control
placental bleeding as they do postpartally.
For some women, then, the stage of
attachment between weeks 6 and 12 can
lead to the most severe, even life
threatening bleeding.
Causes of Spontaneous Miscarriage
• The most frequent cause of miscarriage in
the first trimester of pregnancy is
abnormal fetal development, due either to
a teratogenic factor or to a chromosomal
aberration. In other miscarriages,
immunologic factors may be present or
rejection of the embryo through an
immune response may occur.
Spontaneous Miscarriage • Another common cause of early miscarriage
involves implantation abnormalities, as up
• Abortion is a medical term for any
to 50% of zygotes probably never implant
interruption of a pregnancy before a fetus
securely because of inadequate
is viable (i.e., able to survive outside the
endometrial formation or from an
uterus if born at that time), but it is better to
inappropriate site of implantation. With
speak of these early pregnancy losses as
inadequate implantation, the placental
spontaneous miscarriages to avoid
circulation does not develop adequately
confusion with intentional terminations of
enough to support the pregnancy.
pregnancies.
• Miscarriage may also occur if the corpus
• A viable fetus is usually defined as a fetus of
luteum on the ovary fails to produce
more than 20 to 24 weeks of gestation or
enough progesterone to maintain the
one that weighs at least 500 g. A fetus born
decidua basalis. Progesterone therapy may
before this point is considered a
ANGELES, MICAELLA N.
, be attempted to prevent this if this cause is will drain and bleeding will reappear. Women
documented. are apt to be extremely worried at the sight of
• Ingestion of alcohol at the time of bleeding. They need to talk with a
conception or during early pregnancy can sympathetic, supportive person about
contribute to pregnancy loss because of how distressed they are feeling.
abnormal fetal growth. • Women with threatened miscarriages
• Urinary tract infections may be a cause but often look for reasons why this could have
are more strongly associated with preterm happened, such as running up a flight of
birth. stairs, forgetting to take an iron pill, or getting
• Systemic infections such as rubella, angry with an older child. Being assured that
syphilis, poliomyelitis, cytomegalovirus, none of these events causes miscarriage
and toxoplasmosis readily cross the can help to minimize the guilt a woman may
placenta and so may also be responsible. feel.
With an infection, if the fetus fails to grow, • If the spotting with a threatened miscarriage
estrogen and progesterone production by is going to stop, it usually does so within 24
the placenta falls and leads to endometrial to 48 hours after a woman reduces her
sloughing. With the sloughing, activity. Once bleeding stops, she can
prostaglandins are released; uterine gradually resume normal activities.
contractions and cervical dilatation along • Coitus may be restricted for 2 weeks,
with expulsion of the products of the however, to prevent infection and to avoid
pregnancy begin. Because miscarriage can inducing further bleeding.
occur from so many causes and, because • As many as 50% of women with a threatened
the cause is often difficult to determine, miscarriage continue the pregnancy; for the
couples may have difficulty understanding other 50%, unfortunately, the threatened
why it happened to them (Box 21.3). miscarriage changes to imminent, or
inevitable, miscarriage and the pregnancy
Threatened Miscarriage ends.
• there is a risk of losing a pregnancy, but it
hasn’t happened yet. Imminent (Inevitable) Miscarriage
• Symptoms of a threatened miscarriage • A threatened miscarriage becomes an
begin as vaginal bleeding, initially only imminent (i.e., inevitable) miscarriage if
scant and usually bright red. uterine contractions and cervical dilation
• A woman may notice slight cramping, but occur as, with cervical dilation, the loss of
no cervical dilatation is present on vaginal the products of conception cannot be
examination. halted (stopped).
• A woman with an apparent threatened • A woman who reports cramping or uterine
miscarriage may be asked to come to the contractions is usually asked to come to the
clinic or office to have fetal heart sounds hospital or office, where she is examined.
assessed or an ultrasound performed to She should save any tissue fragments she
evaluate the viability of the fetus. Blood may has passed and bring them with her so they
be drawn to test for human chorionic can be analyzed for an abnormality such as
gonadotropin (hCG) hormone at the start gestational trophoblastic disease
of bleeding and again in 48 hours (if the (hydatidiform mole). If no fetal heart
placenta is still intact, the level in the sounds are detected and an ultrasound
bloodstream should double in this time). If reveals an empty uterus or nonviable
it does not double, poor placental fetus, her primary health care provider
function is suspected and the pregnancy may perform a dilatation and curettage
probably will be lost. (D&C) or a dilation and evacuation (D&E)
• Avoidance of strenuous activity for 24 to to ensure all the products of conception
48 hours is the key intervention, assuming are removed.
the threatened miscarriage involves a live • Be certain the woman has been told the
fetus and presumed placental bleeding. pregnancy was already lost and that all
Complete bed rest is usually not procedures, such as suction curettage, are
necessary as this may appear to stop the to clean the uterus and prevent further
vaginal bleeding but only because blood complications such as infection and not
pools vaginally. When a woman does to end the pregnancy.
ambulate again, the vaginal blood collection
ANGELES, MICAELLA N.
shown:
PREGNANCY
Friday, 21 February 2025
3:23 pm
BLEEDING DURING PREGNANCY
• Vaginal bleeding during pregnancy is always
a deviation from the normal, is always
potentially serious, may occur at any point
during pregnancy, and is always frightening.
It must always be carefully investigated
because it can impair both the outcome of
the pregnancy and the woman’s health or
life.
• The primary causes of bleeding during
pregnancy:
• Because the uterus is a nonessential body
organ, danger to the fetal blood supply
occurs when a woman’s body begins to
decrease blood flow to peripheral organs
(although the increased blood volume of
pregnancy allows more than normal blood
loss before hypovolemic shock processes
begin).
• Signs of hypovolemic shock occur when
10% of blood volume, or approximately 2
units of blood (1L), have been lost; fetal
distress occurs when 25% of blood
volume is lost
When a person is in shock, their body
activates a survival response to maintain
• Although vaginal bleeding may be innocent, blood flow to the most critical organs
any degree of this during pregnancy is a (brain, heart, lungs, etc.) that are
potential emergency because it may mean essential for life. This happens because
the placenta has loosened and cut off shock usually causes low blood
nourishment to the fetus. Also, the amount pressure or poor circulation.
of blood visualized may be only a fraction of 1. Vasoconstriction (narrowing of blood
the blood actually being lost because an vessels) occurs in non-essential areas, like
undilated cervix and intact membranes the skin, arms, and legs, to redirect blood
contain blood within the uterus. flow to vital organs.
• A woman with any degree of bleeding, 2. This reduced blood flow to the skin makes it
therefore, needs to be evaluated for the feel cold and look pale or clammy.
possibility she is experiencing a significant It's the body's way of prioritizing oxygen
blood loss or is developing hypovolemic and nutrients to organs that are crucial
shock. for survival during emergencies like
ANGELES, MICAELLA N.
, shock. This is why cold, clammy skin is a miscarriage or is termed a premature or
key symptom of shock. immature birth (Gilbert, 2011).
• Spontaneous miscarriage occurs in 15% to
30% of all pregnancies and arises from
natural causes (McNair & Altman, 2011).
• A miscarriage is an early miscarriage if it
occurs before week 16 (4 months) of
pregnancy and a late miscarriage if it
occurs between weeks 16 and 24.
• For the first 6 weeks of pregnancy, the
developing placenta is tentatively attached
to the decidua of the uterus; during weeks 6
to 12, it is moderately attached. After week
12, the attachment is penetrating and deep.
Because of these degrees of attachment
achieved at different weeks of pregnancy, it
is important to attempt to establish the week
of the pregnancy at which bleeding has
• Because “normal” blood pressure varies become apparent.
from woman to woman, it is important to • Bleeding before week 6 is rarely severe;
know the baseline blood pressure for a bleeding after week 12 can be profuse
pregnant woman when evaluating for because the placenta is implanted so
hypovolemic shock. deeply. Fortunately, at this time, with such
deep placental implantation, the fetus tends
to be expelled as in natural childbirth before
the placenta separates. Uterine
contractions, however, then help to control
placental bleeding as they do postpartally.
For some women, then, the stage of
attachment between weeks 6 and 12 can
lead to the most severe, even life
threatening bleeding.
Causes of Spontaneous Miscarriage
• The most frequent cause of miscarriage in
the first trimester of pregnancy is
abnormal fetal development, due either to
a teratogenic factor or to a chromosomal
aberration. In other miscarriages,
immunologic factors may be present or
rejection of the embryo through an
immune response may occur.
Spontaneous Miscarriage • Another common cause of early miscarriage
involves implantation abnormalities, as up
• Abortion is a medical term for any
to 50% of zygotes probably never implant
interruption of a pregnancy before a fetus
securely because of inadequate
is viable (i.e., able to survive outside the
endometrial formation or from an
uterus if born at that time), but it is better to
inappropriate site of implantation. With
speak of these early pregnancy losses as
inadequate implantation, the placental
spontaneous miscarriages to avoid
circulation does not develop adequately
confusion with intentional terminations of
enough to support the pregnancy.
pregnancies.
• Miscarriage may also occur if the corpus
• A viable fetus is usually defined as a fetus of
luteum on the ovary fails to produce
more than 20 to 24 weeks of gestation or
enough progesterone to maintain the
one that weighs at least 500 g. A fetus born
decidua basalis. Progesterone therapy may
before this point is considered a
ANGELES, MICAELLA N.
, be attempted to prevent this if this cause is will drain and bleeding will reappear. Women
documented. are apt to be extremely worried at the sight of
• Ingestion of alcohol at the time of bleeding. They need to talk with a
conception or during early pregnancy can sympathetic, supportive person about
contribute to pregnancy loss because of how distressed they are feeling.
abnormal fetal growth. • Women with threatened miscarriages
• Urinary tract infections may be a cause but often look for reasons why this could have
are more strongly associated with preterm happened, such as running up a flight of
birth. stairs, forgetting to take an iron pill, or getting
• Systemic infections such as rubella, angry with an older child. Being assured that
syphilis, poliomyelitis, cytomegalovirus, none of these events causes miscarriage
and toxoplasmosis readily cross the can help to minimize the guilt a woman may
placenta and so may also be responsible. feel.
With an infection, if the fetus fails to grow, • If the spotting with a threatened miscarriage
estrogen and progesterone production by is going to stop, it usually does so within 24
the placenta falls and leads to endometrial to 48 hours after a woman reduces her
sloughing. With the sloughing, activity. Once bleeding stops, she can
prostaglandins are released; uterine gradually resume normal activities.
contractions and cervical dilatation along • Coitus may be restricted for 2 weeks,
with expulsion of the products of the however, to prevent infection and to avoid
pregnancy begin. Because miscarriage can inducing further bleeding.
occur from so many causes and, because • As many as 50% of women with a threatened
the cause is often difficult to determine, miscarriage continue the pregnancy; for the
couples may have difficulty understanding other 50%, unfortunately, the threatened
why it happened to them (Box 21.3). miscarriage changes to imminent, or
inevitable, miscarriage and the pregnancy
Threatened Miscarriage ends.
• there is a risk of losing a pregnancy, but it
hasn’t happened yet. Imminent (Inevitable) Miscarriage
• Symptoms of a threatened miscarriage • A threatened miscarriage becomes an
begin as vaginal bleeding, initially only imminent (i.e., inevitable) miscarriage if
scant and usually bright red. uterine contractions and cervical dilation
• A woman may notice slight cramping, but occur as, with cervical dilation, the loss of
no cervical dilatation is present on vaginal the products of conception cannot be
examination. halted (stopped).
• A woman with an apparent threatened • A woman who reports cramping or uterine
miscarriage may be asked to come to the contractions is usually asked to come to the
clinic or office to have fetal heart sounds hospital or office, where she is examined.
assessed or an ultrasound performed to She should save any tissue fragments she
evaluate the viability of the fetus. Blood may has passed and bring them with her so they
be drawn to test for human chorionic can be analyzed for an abnormality such as
gonadotropin (hCG) hormone at the start gestational trophoblastic disease
of bleeding and again in 48 hours (if the (hydatidiform mole). If no fetal heart
placenta is still intact, the level in the sounds are detected and an ultrasound
bloodstream should double in this time). If reveals an empty uterus or nonviable
it does not double, poor placental fetus, her primary health care provider
function is suspected and the pregnancy may perform a dilatation and curettage
probably will be lost. (D&C) or a dilation and evacuation (D&E)
• Avoidance of strenuous activity for 24 to to ensure all the products of conception
48 hours is the key intervention, assuming are removed.
the threatened miscarriage involves a live • Be certain the woman has been told the
fetus and presumed placental bleeding. pregnancy was already lost and that all
Complete bed rest is usually not procedures, such as suction curettage, are
necessary as this may appear to stop the to clean the uterus and prevent further
vaginal bleeding but only because blood complications such as infection and not
pools vaginally. When a woman does to end the pregnancy.
ambulate again, the vaginal blood collection
ANGELES, MICAELLA N.
