Antepartum Hemorrhage Flashcards
(34 cards)
Antepartum haemorrhage (APH)
Bleeding from or into the genital tract after the 28th week of pregnancy but before the birth of the baby
So bleeding in 1
st and 2nd stage of labor are thus included
At term, APH is difficult to distinguish from a ‘show’ which is the release of cervical mucus in early stages of
labour.
Slight vaginal bleeding (bloody show) is common during active of phase labor and is the consequence of
effacement and dilatation of the cervix, with tearing of small vessels.
Aetiology of APH
Placenta causes (70%)
a) Placenta praevia
b) Abruptio placenta
c) Vasa praevia
Local cause (5%)
a) Cervical polyp
b) Cervical carcinoma
c) Cervicitis
d) Vaginal trauma
e) Vaginal infection
Unexplained (25%)
History taking for APH
How much bleeding?
Triggering factors (e.g. postcoital bleed).
Associated with pain or contractions?
Is the baby moving?
Last cervical smear (date/normal or abnormal)?
Past medical history; for bleeding disorders or liver disease or any coagulopathy
Phys Examination of APH
Vital signs- Pulse, blood pressure and haemodynamic stability.
Estimate amount of bleeding immediately,
Patient’s mental status.
Is the uterus soft or tender and firm?
Fetal heart auscultation/CTG.
Speculum vaginal examination, to visualize the cervix (after excluding placenta praevia, by using U/sound).
If no cervical leision identified, do digital exam or pelvic U/S to determine if cervical dilation present
Investigations for APH
- FBC - acute blood loss may not be reflected in the Hb level until homeostasis has been reestablished.
- Coagulation profile- obtaining a platelet count, serum fibrinogen level, prothrombin time (PT), and aPTT
- If suspected praevia/abruption, crossmatch six units of blood.
- Ultrasonography- accurate method of determining cause of bleeding in late 2nd trimester and 3rd trimester
Placenta Praevia
Placenta implanted partially or completely over the lower uterine segment (over and/or adjacent to the internal os)
Characterised by painless PV bleeding
Placenta covering or encroaching on cervical os may be associated with bleeding, either provoked or spontaneous
theoretical Etiology of placenta previa
Exact cause is idiopathic but the following theories are postulated.
1. Dropping down theory: fertilized ovum drops down and is implanted in the lower segment.
2. Persistence of chorionic activity in decidua capsularis and its subsequent development into capsular placenta
3. Defective decidua, results in spreading of chorionic villi over a wide area in uterine wall to get nourishment.
4. Big surface area of the placenta as in twins may encroach onto the lower segment.
Risk factors of placenta previa
a) Multiparity
b) Increase maternal age above 35
c) Prior C/section / any scar (myomectomy/hysterotomy)
d) Placenta size and abnormality (succenturiate lobes)
e) Prior curettage
f) Smoking (Cause placenta hypertrophy to compensate CO
induced hypoxemia
Types or degrees of placenta previa:
There are 4 types depending on the degree of extension of placenta into the lower segment.
Type- I (Low-lying): Major part of the placenta is attached to upper
segment and only the lower margin encroaches onto the lower
segment but not up to the os- (2cm away from os)
Type- II (Marginal): Placenta reaches the margin of the internal os but
does not cover it. Futher subdivided into:
(IIa- Anterior, IIb- posterior)
Type- III (Incomplete or partial central): Placenta covers the internal os
partially (covers internal os when closed but does not entirely do
so when fully dilated).
Type- IV (Central or total): Placenta completely covers the internal os even after it is fully dilated.
NB: Type III and IV constitute about 1
/3 of cases. Clinically, the above types are graded into mild degree (Type-I
and II anterior) and major degree (Type-II posterior, III and IV)
why is type II known as Dangerous placenta previa
Dangerous placenta previa is referred to type-II posterior placenta previa bec;
a) Major thickness of placenta (about 2.5 cm) overlies the sacral promontory,
diminishing anteroposterior diameter of the inlet and prevents engagement of
the presenting part.
b) Vaginal delivery is more likely to cause Placenta compression
c) Has more chance of cord compression or cord prolapse
Cause of bleeding in placenta previa
Inelastic placenta is sheared off the wall of the lower segment as the lower segment progressively dilates/grows,
leading to opening up of uteroplacental vessels and episodes of bleeding.
This placenta separation is a physiological phenomenon and so bleeding is inevitable.
But also placenta separation can be provoked by trauma including vaginal examination, coital act, and external
version or during high rupture of the membranes.
Mechanisms of spontaneous bleeding control in placenta previa
1) Thrombosis of open sinuses
2) Mechanical pressure by the presenting part
3) Placental infarction.
Placental migration
Lower uterine segment grows from 0.5cm at 20 weeks to over 5cm(10 fold) at term
Placental migration may result by;
Relocation of lower placental edge away from the cervical os with progressive increase in the length of lower
uterine segment
Due to trophotropism (growth of trophoblastic tissue towards the fundus), placenta previa may resolve
Repeat scan after 32 weeks
Clinical features of placenta previa
- Painless PV bleeding- of sudden onset, apparently causeless and recurrent.
Bleeding usually appear near the end of 2nd trimester or later, but it can begin even before mid pregnancy. - Uterine size corresponds to GA
- Relaxed, soft and elastic uterus without tenderness
- Persistence of malpresentation- e.g., breech or transverse or unstable lie.
- Head usually floating in contrast to the period of gestation
- Fetal heart sound heard-
- Stallworthy’s sign- Slowing of fetal heart rate on pressing the head down into the pelvis which promptly recovers
as the pressure is released- suggest low lying placenta especially of posterior type - Vulval inspection: strictly no VE as it can provoke further separation of placenta with torrential hemorrhage.
Note- bleeding, character of the blood- bright red or dark coloured and the amount of blood loss- to be assessed from the
blood stained pads/clothings
Diagnosis of APH
Painless and recurrent vaginal bleeding in 2nd half of pregnancy is placenta previa unless proved otherwise.
1. Obstetric ultrasound
Differential diagnosis of APH
- Placenta abruption
- Local cervical lesion
Polyps
Carcinoma
Cervicitis
Complications of placenta previa
Maternity
1. Antepartum hemorrhage leading to haemorrhagic shock and anaemia
2. Postpartum hemorrhage – due to inability for the uterus to contract effectively
3. Malpresentation
4. Increased incidence of operative interference.
5. Premature labor- either spontaneous or induced
6. Early rupture of the membranes
7. Slow dilatation of the cervix leading to prolonged labour
8. Shehans syndromes- due to necrosis of anterior pituitary gland
9. Puerperal sepsis- due to reduced blood supply and hence prone to infection
10. DIC – Due to loss of fibrin
Fetal complications
1. Prematurity
2. Asphyxia
3. Birth injuries at delivery.
4. Congenital malformation is three times more common in placenta previa.
5. Intrauterine death- due to severe degree of placental separation, with maternal hypovolemia, shock and Cord
prolapse
Management of Placenta Praevia
Definitive treatment depends on; duration of pregnancy, fetal and maternal status and extent of hemorrhage.
Can either be Expectant management or Active (Definite) management
All cases of APH should be admitted no matter the amount of bleeding- either actively bleeding or not because:
Regard all the cases of APH to be as due to placenta previa until proven otherwise
Bleeding may recur sooner or later
If bleeding is relatively minor and fetus uncompromised, admit for observation, until at least 24 hours has passed
without further bleeding.
Admit those with major placenta praevia and recurrent bleeding from 34 weeks, and only consider home mgt in pts
who have not bled and after careful risk assessment
Clinical assessment
Primary survey- ABCDE
Amount of blood loss- note general condition, pallor, pulse rate and blood pressure
Abdominal examination- ascertain any uterine tenderness and auscultation to note fetal heart rate
Vaginal inspection- to observe for any active bleeding
Large bore IV cannula
Blood for HB, Blood group and X match
Confirm diagnosis by U/S
Expectant Management
Aim: continue pregnancy for fetal maturity without
compromising the maternal health.
But secure blood for transfusion; and make arrangement for
cesarean section available throughout
This approach include
Bed rest /No VEs
IV line
Investigation (HB, Blood grouping, X match, U/S)
Haematinics and replace bld lost with adequate BT
Vulva pad counts
Steroids if less than 34 weeks
Give Rh Ig to all unsensitized Rh negative women
Expectant tx is carried up to 37 weeks of pregnancy
Definitive management (Delivery)
Criteria for expectant management
Criteria for expectant management include
Mother in good health status- (Hb > 10 g%; Hct > 30%)
GA of less than 37 weeks
No active bleeding
Assured Fetal well being (USG)- good FH
Consider preterm delivery if:
a) Recurrence and heavy haemorrhage
b) IUFD
c) Congenital malformation on investigation
Hospital setting is ideal but home care can be allowed if:
a) Pt lives close to hospital
b) 24-hour transportation is available
c) Bed rest assured
d) Pt is well motivated to understand the risks
Indications of definitive management (delivery)
a) Bleeding at or after 37 weeks of pregnancy
b) Woman in labor
c) Pt in exsanguinated state on admission
d) Bleeding is continuing and of moderate degree or a massive (1500 mL) bleed
e) IUFD or known to be congenitally deformed.
Caesarean section for all placenta within 2cm from os
Abruptio Placenta
Defined as premature separation of a normally sited placenta
Bleeding is maternal and/or fetal and abruption is acutely dangerous for both the mother and fetus
From the latin: abruptio placentae - “rending asunder of the placenta,
Classification of abruptio placenta
a) Revealed- blood insinuates downwards between membranes and decidua and ultimately,
the blood comes out of the cervical canal to be visible externally
b) Concealed- blood collects behind separated placenta or collected in between the
membranes and decidua.
c) Mixed- some of the blood collects inside (concealed) and a part is expelled out (revealed)
Risk factors of abruptio placenta
a) Increased maternal age
b) High parity- para 5 and above
c) Maternal hypertension (chronic or pregnancy-induced e.g., pre- eclampsia)
d) Premature rupture of membranes
e) Polyhydramnios
f) Placental abruption in a prior pregnancy
g) Pregnancy after in vitro fertilization (IVF)
h) Trauma
i) Short umbilical cord
j) Folate deficiency
k) Substance abuse (e.g., cocaine, amphetamines, tobacco)
l) Placental anomaly: Circumvallate placenta
m) Sick placenta: Poor placentation
n) Thrombophilias- inherited or acquired is associated with increased risk of placental infarcts or abruption
Pathophysiology of abruptio placenta
Most common risk factors is maternal HTN, either chronic or as a result of
preeclampsia.
That may lead to failure of adequate placental implantation.
Placental separation may be due to an inherent weakness or anomaly in the spiral
arterioles.
Premature placental separation is initiated by hemorrhage into the decidua basalis
with formation of a decidual hematoma.
The resulting separation of decidua from basal plate predisposes to further separation and bleeding, as well as to
compression and destruction of placental tissue.
Rupture of the basal plate may also occur, thus communicating the hematoma with the intervillous space
Decidual hematoma may be small & self limited; only evident after expulsion of placenta (retroplacental
hematoma).
As uterus remains distended by conceptus, it fails to contract and therefore fails to compress torn bleeding points.
Blood may either dissect upward toward the fundus, resulting in a concealed hemorrhage, or
extend downward toward the cervix, resulting in an external or revealed hemorrhage
