Abortion (miscarriage)

Defined as the termination of pregnancy before 24 weeks' gestation and/or fetus/embryo weighing 500 grams or less. Ectopic pregnancy and gestational trophoblastic disease are not included. The medical term 'spontaneous abortion' should be replaced with the term 'miscarriage'.¹

• Threatened miscarriage: mild symptoms of bleeding. Usually little or no pain. The cervical os is closed.
• Inevitable miscarriage: heavy bleeding with clots and pain, cervical os is open. Excessive bleeding may cause collapse.
• Incomplete miscarriage: if either conception sac or placenta remain (or suspected).
• Missed miscarriage: fetus dead but retained. Uterus small for dates. Pregnancy test positive for several days after fetus dies. Presents with history of threatened abortions and persistent dirty, brown discharge. Early pregnancy symptoms may have decreased or gone.
• Habitual or recurrent miscarriage: three or more consecutive abortions.

Often no cause is found but common recognised causes include:

• Abnormal fetal development
• Genetic balanced parental translocation
• Uterine abnormality
• Incompetent cervix (second trimester)
• Placental failure
• Multiple pregnancy
• Immunological
• Infections
• Endocrine: e.g. luteal phase deficiency, polycystic ovary syndrome.

• Miscarriage occurs in 10-20% of clinical pregnancies.¹
• One study of 198 pregnancies found that 22% were lost before the expected onset of menses and another 10% were later, clinically recognized losses.²
• 85% of spontaneous miscarriages occur in the first trimester.

Risk Factors

• Age: more frequent in women aged >30 years, and even more common in aged >35 years.
• Incidence increases with number of births: 6% in first and second pregnancies and 16% in further pregnancies.
• Cigarette smoking >14 per day doubles risk over non-smokers.
• Alcohol abuse - risk doubled with twice weekly alcohol and trebled with daily alcohol use.
• Illicit drug use.
• Uterine surgery or abnormalities e.g. incompetent cervix.
• Connective tissue disorders (SLE, anti-phospholipid antibodies-lupus anticoagulant/anticardiolipin antibody).
• Uncontrolled diabetes mellitus.

• Most cases present with vaginal bleeding and pain that should be worse for the patient than a period.
• Patient may also have seen products of conception but may confuse these with clots.
• Signs In cases of first trimester bleeding look for:
• Is patient shocked through blood loss?
• Are there products of conceptions in the cervical canal? (Remove with sponge forceps).
• Is cervical os open? (External os of multigravida usually admits the tip of the finger).
• Is bleeding from cervical lesions and not uterus?
• Is uterine size appropriate for dates?

• Ectopic pregnancy:
  • The single most important diagnosis to exclude.
  • In ectopic pregnancy, the pain is usually greater, may be unilateral, and usually precedes the bleeding.
  • Compared to a miscarriage, the loss is usually lighter and darker - almost black in some cases - and there is acute pain on manipulating the cervix ('cervical excitation').
• Neoplasia
• Hydatiform mole
• Chorionic cyst
• Subchorionic haemorrhage.

• The majority of patients can be fully assessed using ultrasound scans and urine-based hCG tests.
• In threatened abortion: ultrasound shows normal size amniotic sac and fetus with beating heart.
• In complete and incomplete abortion: inspect products of conception for completeness.
• Transvaginal ultrasound scan to show whether uterus empty or contains blood or clots.

• Admission to hospital can be avoided in 40% of women with threatened or actual early pregnancy loss.¹
• Following a miscarriage, all women should have access to support, follow-up and formal counselling when necessary.

Rhesus prophylaxis

The following recommendations are based on the RCOG guideline for Rh prophylaxis:³

• Spontaneous miscarriage:
  • Give Anti-D Ig should be given to all non-sensitised RhD negative women who have a spontaneous complete or incomplete abortion after 12 weeks of pregnancy.
  • If less than 12 weeks of pregnancy, Anti-D Ig should be given when there has been an intervention to evacuate the uterus. The risk of when there has been no instrumentation to evacuate the products of conception is negligible and anti-D Ig is not required.
• Threatened miscarriage:
  • Anti-D Ig should be given to all non-sensitised RhD negative women with a threatened miscarriage after 12 weeks of pregnancy. Where bleeding continues intermittently after 12 weeks' gestation, anti-D Ig should be given at 6-weekly intervals.
  • There is no evidence to support giving anti-D Ig if less than 12 weeks of pregnancy but it may be prudent to give anti-D Ig when bleeding is heavy or repeated or where there is associated abdominal pain particularly if these events occur as gestation approaches 12 weeks. The period of gestation should be confirmed by ultrasound.
• If there is clinical doubt then anti-D should be given.

Non-Drug

• Expectant policy justified in most cases (>75%) in pregnancies of less than 13 weeks duration. Expectant management is often followed by minimal bleeding, as any retained tissue will usually undergo resorption. The passage of tissue may occasionally be associated with heavy bleeding.¹
• Bed rest is no longer recommended for threatened miscarriage.
• The psychological sequelae associated with miscarriage must be appreciated. This includes offering support and follow-up, as well as access to formal counselling when necessary.

Drugs

• Medical and expectant methods are effective in the management of confirmed miscarriage. Various medical methods have been described using prostaglandin analogues (gemeprost or misoprostol) with or without antiprogesterone priming (mifepristone).
• Incomplete miscarriage may be managed with prostaglandin alone. Misoprostol is active orally and vaginally but the vaginal route seems more effective.
• One randomised trial showed no statistical difference in efficacy between surgical and medical evacuation for incomplete miscarriage and for early fetal demise at gestations less than 71 days or sac diameter less than 24mm. Patient acceptability for both methods was equal. There was a reduction in clinical pelvic infection after medical evacuation. With increasing gestation and sac size, the acceptability of medical methods fell to 85%.¹
• If profuse bleeding consider ergometrine.

Surgical

• Clinical indications for offering surgical evacuation include: persistent excessive bleeding, haemodynamic instability, evidence of infected retained tissue and suspected gestational trophoblastic disease.¹
• Suction curettage is safer and easier than sharp/blunt curettage. Serious complications of surgery include perforation, cervical tears, intra-abdominal trauma, intrauterine adhesions and haemorrhage.
• Screening for infection, including Chlamydia trachomatis, should be considered in women undergoing surgical uterine evacuation.¹
• Tissue obtained at the time of miscarriage should be examined histologically to confirm pregnancy and to exclude ectopic pregnancy or gestational trophoblastic disease.¹
• With missed abortion, confirm with ultrasound and perform suction evacuation or medical treatment with mifeprostone followed by vaginal or oral prostaglandins. A minority of women may wish for conservative managements and to await events.

• Septic abortion:
  • Usually presents with malodorous pink vaginal discharge and fever (80% of cases where infection confined to decidua).
  • In more severe form that spreads to the uterine wall, tender lower abdomen and boggy, tender uterus. Tachycardia and occasionally leads to shock and disseminated intravascular coagulation.
  • Take high vaginal/cervical swab for culture. If temperature above 38.4 degrees C, send bloods for culture.
  • Most cases are due to E.coli, streptococci and/or anaerobes. Start metronidazole with a broad spectrum antibiotic, e.g. co-amoxiclav. If necessary, modify treatments according to sensitivities.
  • Evacuate contents of uterus 12 hours later (once patient has stabilised), or earlier if bleeding severe.
  • Hysterectomy may be needed if infection uncontrolled.
• Bleeding normally ceases after complete abortion within 10 days. If part of placenta remains, bleeding may continue with cramps. Confirm with ultrasound, curette again and send tissue for histopathology to exclude choriocarcinoma.

• Threatened abortion is associated with risk of preterm delivery.
• Increased risk of further miscarriages. After three of these consider as recurrent spontaneous miscarriage.

• Encourage reduction of alcohol consumption.
• Smoking cessation and stop illicit drug use.