妇产科学课件：Placenta previa and Abruptio placenta
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2
Placenta previa is an obstetric complication 。
in the second and third trimesters of pregnancy.
serious morbidity and mortality to both the fetus and the mother.
transvaginal ultrasonography transabdominal approach.
16
(3)The time of onset of bleeding, the amount , the frequency is related to type of placenta previa
the third trimester pregnancy
4
ห้องสมุดไป่ตู้
Etiology
The condition may be multifactorial multiparity, multiple gestations, advanced maternal age, previous cesarean delivery, previous abortion, and possibly, smoking.
5
1.scarred or poorly vascularized endometrium in the uterine corpus
Endometrial scarring in the upper segment of the uterus --- initial trophoblastic nidation ---- relatively unscarred lower uterine segment or growth toward the unscarred lower uterine segment.
associated with an increased risk of bleeding, although less than with true placenta previas
13
Clinical manifestation
1.Vaginal bleeding (1) Characters: Painless, in the third
slight
less
17
note: bleeding will be less dramatic or will not
begin until after spontaneous rupture of the membrane or the onset of labor. A few nulliparous patients even reach term without bleeding.
18
2.Signs: Anemia and shock Abdominal exam Uterus ：soft ,relaxed ,and nontender. The infant will present in an oblique or
causes of vaginal bleeding
3
Incidence
approximately 1 in 200 deliveries and only 20% are total
90% of patient will be parous the major reason of hemorrhage in
8
Classification
1. Complete or central placenta previa 2. Partial placenta previa 3. Marginal placenta previa
9
10
11
12
Low-lying placenta
apparent placenta previa in the second trimester.
Placenta previa and Abruptio placenta
1
Placenta previa
Definition
the placenta is implanted partially or completely over the lower uterine segment within the zone of effacement and dilatation of the cervix.
type Central Partial Marginal
onset
Earlier, 28th week
Between central and marginal
Late, 37~40 weeks
amount
Severe, shock
between central and
marginal
Frequency more
6
2. large placenta twin pregnancy increased placental surface area ---- a reduction in uteroplacental oxygen or nutrient delivery.
7
3.Abnormal forms of placenta 4.The retardation of zygote growth
trimester, sudden onset, causeless, profuse, recurrent, Unrelated to activity, often occurs during sleep A few nulliparas no bleeding
14
(2)Reasons: Mechanical separation Formation of the lower segment
or effacement and dilatation of cervix Placentitis Rupture of poorly supported venous lakes in the decidua basalis
15
Note: placenta lies in the posterior portion of the lower uterine segment----difficult to ascertain.
Placenta previa is an obstetric complication 。
in the second and third trimesters of pregnancy.
serious morbidity and mortality to both the fetus and the mother.
transvaginal ultrasonography transabdominal approach.
16
(3)The time of onset of bleeding, the amount , the frequency is related to type of placenta previa
the third trimester pregnancy
4
ห้องสมุดไป่ตู้
Etiology
The condition may be multifactorial multiparity, multiple gestations, advanced maternal age, previous cesarean delivery, previous abortion, and possibly, smoking.
5
1.scarred or poorly vascularized endometrium in the uterine corpus
Endometrial scarring in the upper segment of the uterus --- initial trophoblastic nidation ---- relatively unscarred lower uterine segment or growth toward the unscarred lower uterine segment.
associated with an increased risk of bleeding, although less than with true placenta previas
13
Clinical manifestation
1.Vaginal bleeding (1) Characters: Painless, in the third
slight
less
17
note: bleeding will be less dramatic or will not
begin until after spontaneous rupture of the membrane or the onset of labor. A few nulliparous patients even reach term without bleeding.
18
2.Signs: Anemia and shock Abdominal exam Uterus ：soft ,relaxed ,and nontender. The infant will present in an oblique or
causes of vaginal bleeding
3
Incidence
approximately 1 in 200 deliveries and only 20% are total
90% of patient will be parous the major reason of hemorrhage in
8
Classification
1. Complete or central placenta previa 2. Partial placenta previa 3. Marginal placenta previa
9
10
11
12
Low-lying placenta
apparent placenta previa in the second trimester.
Placenta previa and Abruptio placenta
1
Placenta previa
Definition
the placenta is implanted partially or completely over the lower uterine segment within the zone of effacement and dilatation of the cervix.
type Central Partial Marginal
onset
Earlier, 28th week
Between central and marginal
Late, 37~40 weeks
amount
Severe, shock
between central and
marginal
Frequency more
6
2. large placenta twin pregnancy increased placental surface area ---- a reduction in uteroplacental oxygen or nutrient delivery.
7
3.Abnormal forms of placenta 4.The retardation of zygote growth
trimester, sudden onset, causeless, profuse, recurrent, Unrelated to activity, often occurs during sleep A few nulliparas no bleeding
14
(2)Reasons: Mechanical separation Formation of the lower segment
or effacement and dilatation of cervix Placentitis Rupture of poorly supported venous lakes in the decidua basalis
15
Note: placenta lies in the posterior portion of the lower uterine segment----difficult to ascertain.