Antepartum Haemorrhage (APH)
Haemorrhage is the leading cause of maternal mortality worldwide, contributing to about 25-30% in Nigeria, and increases the risk of perinatal morbidity and mortality. Antepartum haemorrhage is, therefore, an obstetric emergency.
APH is defined as vaginal bleeding that occurs anytime between the age of viability and before the onset of labour. In Nigeria, age of viability is 28 weeks; 24 weeks in UK.
EPIDEMIOLOGY
It complicates about 2-5% of pregnancies in developed countries. However, the exact incidence in Nigeria is difficult to determine due to lack of reliable data.
AETIOLOGY
The causes of APH are classified into placental, foetal, and maternal/local. Placental causes are the most common and most worrisome because they pose a significant threat to the lives of both the mother and the foetus, and present with more severe bleeding than the other causes.
- Placental causes: placenta praevia and placental abruption
- Foetal cause: vasa praevia
- Maternal/local causes: cervical ectropion/erosion, cervical polyp, cervical carcinoma, cervicitis, vaginitis, vaginal trauma, varicosities of the vulva or introitus
INVESTIGATIONS
Could either be general or specific.
General investigations include: PCV estimation, full blood count, blood grouping and cross matching, serum electrolytes, urea, creatinine, urinalysis, urine microscopy, clotting profile, and arterial blood gas.
Specific investigations include: transbdominal or transvaginal ultrasound, magnetic resonance imaging (MRI), examination in theatre (most accurate for placenta praevia done at 38 weeks gestation). Pelvic/vaginal examination should NOT be done until placenta praevia has been excluded.
1. PLACENTA PRAEVIA: occurs when the placenta is in part or entirely in the lower uterine segment, because it is seen there at imaging, caesarean section, or at examination in theatre (EIT). The incidence varies, and in developed countries, could range between 0.2-1percent of all pregnancies.
The exact aetiology is not known, however, some predisposing factors include: advanced maternal age (>35 years), smoking, high parity, multiple pregnancy, previous uterine surgery, uterine fibroids occupying the upper uterine segment, previous placenta praevia (4-8% recurrence risk).
It can be classified into 4 as follows:
- Type I: the placenta encroaches on the lower uterine segment, but does not reach the internal os.
- Type II: the placenta reaches the internal os, but doesn’t cover it. It is further divided into IIa (anterior) and IIb (posterior).
- Type III: the placenta covers the internal os by reaching across to the farther margin, but ceases to do so as the cervix dilates.
- Type IV: the placenta completely covers the internal os, even when the cervix is dilated.
Types I and IIa are considered minor placenta praevia.
The patients present with painless, bright red bleeding per vaginum, commonly between 32 and 36 weeks. The bleeding may trigger Braxton-Hicks contractions. Warning signs include light headedness, restlessness, maternal distress, panic or collapse. On examination, there could be pallor, the abdomen is soft and non-tender, and foetal lie and presentation may be abnormal.
Treatment: The MACAFEE REGIMEN (conservative management) is instituted for foetuses not close to term, i.e. </= 36 weeks, and in women who have minimal bleeding. It involves: admission of the patient in to a fully equipped and staffed maternity unit, prophylactic transfusions to maintain PCV >/=30%, twice daily monitoring of foetal heart rate, foetal kick chart, constant assessment of foetal wellbeing via ultrasound every 2-4 weeks, administration of anti-D immunoglobulin if mother is Rh negative. The patient should keep a perineal pad, and it should be inspected regularly. Delivery should be scheduled at 37-38 weeks gestation. At least four units of cross matched blood should be available if needed for emergency situations.
ACTIVE MANAGEMENT involves: gaining IV access with two large bore cannulae, administration of crystalloids, transfusion with cross matched packed cells to maintain PCV >30%, monitoring urinary output via Foley catheter, monitoring of maternal pulse and blood pressure every 15 minutes – 1hour. If the bleeding is severe, a caesarean section should be done, regardless of the gestational age.
DELIVERY for minor placenta praevia, with foetus in vertex presentation in a haemodynamically stable mother with adequate pelvis should be by spontaneous vaginal delivery. The membranes should be ruptured artificially, and an IV oxytocin infusion should be given to induce labour, with close maternal and foetal monitoring. An emergency caesarean section is done if there is foetal distress. Major placenta praevia is an indication for caesarean section.
Complications:
- Postpartum haemorrhage
- Hypovolaemic shock
- Thromboembolism
- Coagulation defects
- Placenta accreta, increta or percreta
- Intrauterine growth restriction
- Foetal anaemia
- Respiratory distress syndrome
2. ABRUPTIO PLACENTAE: is the premature separation of a normally sited placenta from the uterine wall. The exact aetiology is not known, however, some predisposing factors include: hypertension, including pre-eclampsia and eclampsia, trauma to the abdomen, previous history of abruption, high parity, advanced maternal age, smoking, cocaine use, multiple gestation, polyhydramnios, folate deficiency, uterine fibroids, among others. >/= 50% abruption isn’t compatible with foetal life.
It can be classified into three categories:
- Concealed type: no obvious bleeding through the vagina. The blood can reach the myometrium, and cause a hard, woody, tender uterus called Couvelaire uterus. If tis progresses, there will be release of tissue thromboplastin into maternal circulation, resulting in disseminated intravascular coagulation (DIC).
- Revealed type: the bleeding is revealed through the vagina.
- Mixed type: some of the blood exits through the vagina, the rest remain retroplacentally located.
The patient presents with the classical symptoms of vaginal bleeding and severe abdominal pain, which could be worsened by uterine contractions. There could also be low back ache, reduced perception of foetal movements, symptoms of shock such as sweating, dizziness, maternal collapse.
Examination findings such as pallor, rapid pulse, and cold clammy extremities suggest shock. Abdominal examination will reveal tense, tender, hard, woody uterus. These findings are more pronounced in the concealed type. The foetal parts are difficult to palpate, and foetal heart beat is inaudible. If the woman is in labour, the uterus may not relax in between contractions. If the abruption is still ongoing, there may be increasing abdominal girth. Vaginal examination may reveal a dilated cervix. Abruptio is confirmed after delivery by finding adherent retroplacental clots.
Treatment: Conservative management is similar to that of placenta praevia.
Active management is similar to that of praevia. It involves setting IV lines and initiating colloid infusion. Blood is taken for necessary investigations. A bedside clotting time should be done. If it is longer than 10 minutes, or if a clot forms and lyses within 30minutes, a coagulation defect is suspected, and fresh frozen plasma is requested for. Intranasal oxygen is given if spO2 is less than 95%, and a Foley catheter is passed to monitor urine output. Clotting time should be estimated every 4 hours for 24 hours.
Once both mother and foetus are stable and the pregnancy is at term, the patient should be made to deliver within 6-8 hours. Amniotomy is done, and labour is augmented with oxytocic infusion, with active management of the third stage of labour to prevent postpartum haemorrhage. Caesarean section is indicated if the foetus is alive, or if there are complications such as foetal distress, transverse lie, inadequate pelvis, severe bleeding, etc.
Complications:
- DIC
- Renal failure
- Ischaemic necrosis of distal organs, e.g. brain, kidneys
- Postpartum haemorrhage and hypovolaemic shock
- Foetal anaemia
- Intrauterine foetal death/Perinatal death
N.B: Placenta praevia is more dangerous for the mother; Placental abruption is more dangerous for the foetus than the mother; Vasa praevia is not dangerous for the mother, but is nearly always fatal for the baby.
REFERENCES
- Textbook of Obstetrics and Gynaecology for Medical Students. Second edition. Edited by Akin Agboola
- Obstetrics by Ten Teachers. 20th Edition