What is Antepartum hemorrhage (Bleeding in late pregnancy) ?
Antepartum haemorrhage (APH) is defined as bleeding from or in to the genital tract, occurring from 24+0 weeks of pregnancy and prior to the birth of the baby. APH complicates 3–5% of pregnancies; and is a leading cause of perinatal and maternal mortality worldwide.
The causes of APH include: placenta praevia, placental abruption and local causes (such as bleeding from the vulva, vagina or cervix). Placenta previa & placental abruption constitute 50% of APH.
Antepartum hemorrhage (Bleeding in late pregnancy) Symptoms
Symptoms of antepartum haemorrhage (APH) consist of vaginal bleeding in late pregnancy and before delivery. Along with vaginal bleeding other symptoms may be-
(a) In APH due to placenta previa, vaginal bleeding is painless, or bleeding occurs after sexual intercourse. Initial episodes are usually mild and ceases spontaneously only to recur. Some types of placenta previa resolve on their own by 32–35 weeks of pregnancy as the lower part of the uterus stretches and thins out. Labor and delivery then can occur normally. If placenta previa does not resolve, cesarean delivery may be needed.
(b) In APH due to placental abruption symptoms include:
- Vaginal bleeding
- Abdominal pain
- Back pain
- Uterine tenderness
- Uterine contractions,
- Firmness in the uterus or abdomen
Antepartum hemorrhage (Bleeding in late pregnancy) Causes
The causes of APH include: placenta praevia, placental abruption and local causes (such as bleeding from the vulva, vagina or cervix). Abruption is more likely to be related to conditions occurring during pregnancy and placenta praevia is more likely to be related to conditions existing prior to pregnancy.
Placenta praevia is defined as a placenta that lies wholly or partly within the lower uterine segment. It occurs in .4%-.8 % of pregnancies. The condition is mostly diagnosed on ultrasound examination.
Classification of placenta previa (Williams)
- Total placenta previa: Internal cervical os is covered completely by placenta.
- Partial placenta previa: Internal cervical os is partially covered by placenta.
- Marginal placenta previa: The placenta is implanted in the lower segment such that the placental edge does not actually reach the internal cervical os but is in close proximity of it.
Factors associated with the development of placenta praevia include:
- increasing maternal parity,
- advancing maternal age,
- increasing placental size (multiple pregnancy),
- endometrial damage (previous dilatation and curettage), endometritis
- previous caesarean section, uterine scars and pathology
- previous myomectomy
- placental abnormalities,
- previous placental praevia, and
- cigarette smoking.
Placental abruption/ abruptio placentae –Placental abruption is the premature separation of a normally situated placenta from the uterine wall, resulting in haemorrhage before the delivery of the foetus. In placental abruption some of the bleeding escapes through the cervix causing external haemorrhage and sometimes bleeding is concealed when blood does not escape externally. Placental abruption can occur in up to 5% of pregnancies.
The precise cause of abruption is unknown, but risk factors for placental abruption include: pre-eclampsia, fetal growth restriction, non-vertex presentations, polyhydramnios, advanced maternal age, multiparty, low body mass index (BMI), pregnancy following assisted reproductive techniques, intrauterine infection, premature rupture of membranes, abdominal trauma (both accidental and resulting from domestic violence), smoking, drug misuse (cocaine and amphetamines) during pregnancy and maternal thrombophilia. Bleeding in first trimester also increases the risk of abruption later in the pregnancy.
Placental abruption is mostly diagnosed on ultrasound examination. Though Sonography is not sensitive for the detection of placental abruption but it is highly specific.
Placenta accrete- When the placenta (or part of the Placenta) invades and is inseparable from the uterine wall, it is called placenta accrete. It can cause bleeding during the third trimester and severe blood loss during delivery.
Other causes-In a small proportion of cases cervicitis, trauma, vulval varicosities (varicose veins at the outer surface of the female genitalia -vulva), genital tumours, genital infections and vasa previa may be the cause of APH. Many of these conditions are evident on the initial speculum examination.
Antepartum hemorrhage (Bleeding in late pregnancy) Diagnosis
Diagnosis of antepartum hemorrhage is first based on clinical suspicion. Initially clinical assessment of women presenting with APH is done by medical person to establish urgency of intervention required to manage maternal or fetal compromise.
If there is no maternal compromise a full history should be taken. It includes history taking to assess coexisting symptoms such as pain, an assessment of the extent of vaginal bleeding, the cardiovascular condition of the mother, and an assessment of fetal wellbeing.
In placenta previa, uterus is felt to be relaxed on palpation and non-tender. Generally presenting part is high up and floating.
In placental abruption, the triad of sudden onset of abdominal pain, bleeding per vagina, tense and tender uterus constitutes the main diagnostic criteria.
Speculum examination- A speculum examination can be useful to identify cervical dilatation or can visualise a lower genital tract cause for the APH.
If placenta praevia is a possible diagnosis (for example, a previous scan shows a low placenta, or there is a high presenting part on abdominal examination, or the bleeding is painless), digital vaginal examination should not be performed until an ultrasound has excluded placenta praevia.
If APH is associated with pain or uterine activity digital vaginal examination can provide information on cervical dilatation.
Blood tests-
·Full blood count with haemoglobin estimation
·Blood grouping with Rh factor
·Screening for coagulation factor
·Liver function tests
·Urea and electrolyte test
Ultrasound scan (USG)-
Women presenting with APH should have an ultrasound scan performed to confirm or exclude placenta praevia, if the placental site is not already known. Transvaginal ultrasound is more accurate than transabdominal in diagnosing placenta previa.
The sensitivity of ultrasound for the detection of retroplacental clot (abruption) is poor. However, when the ultrasound suggests an abruption, the likelihood that there is an abruption is high.
Transvaginal ultrasound (an ultrasound view of the cervix) in combination with color Doppler (which can show blood flowing through veins) is the most effective tool in the diagnosis of vasa previa during pregnancy and can be utilized in patients at risk.
MRI is used only to differentiate different degrees of myometrial invasion.
Antepartum hemorrhage (Bleeding in late pregnancy) Complications
APH is associated with complications for the mother and her foetus. Complications are more likely to occur:
- when haemorrhage is due to a placental cause (abruption or placenta praevia),
- when the bleeding is heavy and
- when the bleeding occurs at early gestations.
For the mother, APH can lead to:
- Anaemia
- Infection
- Maternal shock due to blood loss
- Failure of the kidneys or other organs resulting from significant blood loss
- Blood clotting problems (disseminated intravascular coagulation-DIC)
- Need for a blood transfusion
- Postpartum haemorrhage
- Pronged hospital stay
- Psychological sequelae
- Couvelaire uterus- This may occur after placental abruption. It is a phenomenon wherein the retroplacental blood may penetrate through the thickness of the wall of the uterus into the peritoneal cavity.
- Rarely, when uterine bleeding cannot be controlled, hysterectomy may be necessary.
For the baby, APH can lead to:
- Restricted growth from not getting enough nutrients
- Fetal hypoxia (not getting enough oxygen)
- Premature birth
- Stillbirth
Antepartum hemorrhage (Bleeding in late pregnancy) Prevention
Routine antenatal checkups for early detection of any complication during pregnancy with their proper management such as high blood pressure / pre-eclampsia can help in reducing maternal and foetal complications.
By preventing certain risk factors during pregnancy such as smoking, drug misuse the chances of APH can also be reduced.
Pregnant women should wear seatbelt when in a motor vehicle and seek medical help immediately in case of abdominal trauma from an auto accident, fall or other injury.