Gab Kovacs1 and Paula Briggs2
(1)
Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
(2)
Sexual and Reproductive Health, Southport and Ormskirk Hospital, Southport, UK
Definition
Incidence
Aetilogy and Pathogenesis
Clinical Assessment
History
Examination
Investigations
Treatment
Medical
Surgical
Complications
Prognosis
Definition
This is defined as vaginal bleeding after 20 weeks gestation.
Incidence
It occurs in 2–5 % of pregnancies. Together with postpartum haemorrhage, it is one of the commonest causes of maternal death, although fortunately these are very uncommon in the Western world (less than four per million births).
Aetilogy and Pathogenesis
There are three causes of APH:
· Placenta praevea – including vasa praevia (when there is a blood vessel in the membranes which crosses the internal os)
· Retroplacental haemorrhage (known as placental abruption or accidental haemorrhage)
· Incidental causes from the cervix, vagina or vulva
Recurrent APH occurs when there is more than one episode of bleeding.
Predisposing factors for abruption are a previous pregnancy with abruption, pre-eclampsia, intrauterine growth restriction (IUGR), multiparity, advanced maternal age, low BMI, pregnancy after assisted reproductive technology (ART), polyhydramnios, premature rupture of membranes, abdominal trauma, smoking, and drug use. There is a suggestion that thrombophilias may also be associated with an increased risk of abruption.
For placenta praevia, risk factors include previous placenta praevia, previous caesarian section, previous termination of pregnancy, multiparity, multiple pregnancy, advanced maternal age, smoking, ART conception and a deficient endometrium (scar tissue, submucous fibroid(s), previous curettage and manual removal of the placenta).
Clinical Assessment
History
The degree of emergency depends on the amount of blood loss. Spotting noticed on underwear is the least critical, with minor haemorrhage being less than 50 ml. Loss of between 50 and 1,000 mls is a more major haemorrhage, and if the woman is shocked, or the loss is estimated in excess of 1,000 ml, it is described as massive.
The second important feature in the history is the presence or absence of pain. Placenta praevia is usually painless, whereas abruption is usually associated with abdominal pain.
Incidental causes are usually minor, and painless.
The presence of foetal movements should be questioned.
Examination
Abruption is often associated with uterine contractions and tenderness.
If placenta praevia is suspected on the history, a vaginal examination SHOULD NOT BE PERFORMED.
If placenta praevia and abruption have been excluded, a gentle speculum examination can be performed to diagnose a cervical or vaginal cause of the bleeding.
Investigations
Ultrasound is the most important investigation. This will localise the placental site, and also visualise the retroplacental blood clot.
A full blood count should be performed to assess haemoglobin/haematocrit and platelet count. In Rh negative women a Kleihauer test should be considered.
The foetus should be monitored for signs of distress using CTG.
Treatment
It has to be decided whether urgent intervention is indicated depending on
· amount of bleeding
· degree of pain
· haemodynamic stability
· foetal condition
Medical
· The principles of resuscitation should be followed
· ABC – Airway, Breathing, Circulation
· Steroids should be administered at between 24 and 34 weeks of gestation as a single dose to mature the foetal lungs
· There is no place for tocolytics in APH
Surgical
· Minor – Artificial rupture of membranes and induction of labour
· Major – Emergency Caesarian Section
Complications
· Maternal: shock, renal failure, coagulopathy, anaemia, blood transfusion, infection
APH is an important cause of maternal death
· Foetal: IUGR, prematurity, hypoxia, foetal death
Prognosis
Complications are more likely if the APH is due to a placental bleed (praevea or abruption), the heavier the blood loss, and the earlier in the pregnancy that it takes place.
Pregnancies which are complicated by an APH due to placenta praevia or abruption should be treated as “high risk”