Causes

Despite detailed investigations, no cause can be found in the majority of cases.

Inevitable abortion

The key feature of inevitable abortion is cervical dilatation with an outcome of unavoidable pregnancy loss. The gestation sac separates from the uterine wall and the uterus contracts to expel the conceptus. This uterine activity causes discomfort similar to that of labour contractions. Speculum examination reveals a dilating cervix, possibly with products of conception protruding through. The gestation sac may be expelled complete (complete abortion), or in part, usually with placental tissue retained (incomplete abortion).

The midwife who is called by a woman with signs of inevitable abortion should arrange immediate care. The woman’s vital signs should be recorded and an estimate of blood loss made. If the fetus has been expelled and the woman is bleeding, local policies for the management of the third stage of labour and control of postpartum bleeding should be followed. Any products of conception passed should be saved for inspection. The midwife should refer the woman for medical care either by her GP or by a gynaecologist at her local hospital. If the bleeding is severe or the woman is showing signs of shock, a paramedic team from the local ambulance service should be requested. They will resuscitate the woman and stabilize her condition before transfer to hospital. In hospital, evacuation of retained products of conception (ERPC) from the uterus may be carried out and a blood transfusion may be given if blood loss has been severe.

Medical management of inevitable or incomplete abortion is possible, using prostaglandin analogues such as misoprostol or gemeprost. Once the uterus is empty, vulval hygiene is important for comfort and to reduce the likelihood of infection: the woman should be advised to change her sanitary towels frequently and keep the vulva clean, using a bidet or shower if possible. All women who have required surgical evacuation should be screened for chlamydial infection (RCOG 2006).

If the breasts begin to secrete, the woman should be advised to wear a well-fitting brassiere in order to minimize discomfort. Cabergoline 1 mg may be prescribed by a medical practitioner or qualified midwife prescriber to suppress lactation. If the woman is rhesus negative, anti-D gammaglobulin is given within 60 hours of abortion to prevent isoimmunization and potential rhesus problems in subsequent pregnancies. Women who are non-immune to rubella may be given rubella vaccination at this time and advised to avoid the risk of pregnancy for the next 3 months.

Missed abortion (delayed abortion, silent abortion)

In this condition, bleeding occurs between the gestation sac and the uterine wall and the embryo dies. The uterus ceases to increase in size and as the presence of the retained fetus appears to inhibit menstruation, the woman may think that her pregnancy is continuing, although other signs of pregnancy have disappeared. The bleeding from the vagina varies from nothing, to a trickle of brownish discharge. As the signs of pregnancy gradually disappear, some women become aware that all is not well.

The diagnosis is confirmed by ultrasound. The uterus would eventually expel the fetus spontaneously, but this may not occur for some time. Treatment is usually to evacuate the uterus, either surgically or with misoprostol, either alone or in combination with methotrexate (Creinin et al 2003, Neilson et al 2006). ‘Expectant’ management may be offered: the woman is given the option of returning home for a few days to await spontaneous expulsion of the fetus.

If a well-formed fetus is retained in the uterus, it can become flattened and mummified as a fetus papyraceous (Fig. 54.2), rather than being reabsorbed. This is more commonly associated with a multiple pregnancy.

Figure 54.2 Fetus papyraceous.

(From Beischer et al 1997.)

Recurrent abortion

This is a term used when three or more consecutive spontaneous abortions have occurred. Careful investigation should be undertaken to find the cause. Occasionally, the causative factors are different for each, with no clear single factor associated. However, some conditions may be implicated in recurrent pregnancy loss (Backos & Regan 2006).

Psychological effects

Many women experience a marked grief reaction following abortion and may require considerable counselling and support. Psychological distress may be severe and some women become clinically depressed. The grief experienced by the partner may be as intense as that of the woman, though he is less likely to receive support (Conway & Russell 2000). Staff should treat the parents with sensitivity. The couple may wish to see their baby and staff should take account of their wishes. The guidelines written by the Stillbirth and Neonatal Death Society are useful (SANDS 2009).

After the end of the 24th week of pregnancy, the infant must be registered as a stillbirth (Home Office 2008). Many maternity hospitals offer a funeral or memorial service for pre-viable fetuses and all must offer respectful disposal. In this situation, the hospital chaplain may be a valuable source of support and advice. Antenatal Results and Choices (ARC) can provide non-directive support and counselling for parents who have received high-risk antenatal screening results or diagnosis of a fetal abnormality (ARC 2009).

Therapeutic abortion

Therapeutic abortion has been legal in the UK since 1967, when the Abortion Act became law. This Act allows termination of a pregnancy if two registered medical practitioners are of the opinion that continuance of the pregnancy:

In current legislation, the upper gestation limit for legal termination is defined as the end of the 24th week (Dimond 2001, Human Fertilization and Embryology Act 1990). The only circumstances in which therapeutic abortion may be carried out after the 24th week are:

The law also allows for selective fetal reduction in multifetal pregnancy (see website),

Abortions after 24 weeks may only be carried out in NHS hospitals.

Methods of surgical abortion (Fig. 54.3)

Figure 54.3 Dilatation and vacuum aspiration.

Criminal abortion

This is the termination of a pregnancy outside the terms of the Abortion Act, possibly by unauthorized and untrained persons, and is an offence punishable by law. The incidence has fallen sharply since the introduction of the 1967 Abortion Act. However, cases still occur: four such offences were detected in the year 2000–2001 (Home Department 2001) and seven in 2004–2005 (Home Office 2009). The abortion may be induced either by the woman herself or by some other person, by use of drugs or instruments. Whether successful or not, the action is illegal. The methods used may cause sudden death from haemorrhage, air embolus or vagal inhibition. Because of lack of asepsis, infection readily occurs and may lead to chronic ill-health or salpingitis and sterility (see website).

Signs and symptoms

Often, the minor disorders of pregnancy, such as nausea and breast tenderness, are more severe. The woman may complain of intermittent bleeding per vaginam from around the 12th week of pregnancy. When the mole begins to abort, there may be profuse haemorrhage. Pre-eclampsia may develop even in the early weeks of pregnancy. Severe nausea and vomiting may occur. On abdominal examination, the uterus is usually large for the period of gestation and may feel soft and doughy to the fingers. No fetal parts are palpable and the fetal heart is absent. There may be signs of mild thyrotoxicosis due to the thyroid-stimulating hormone (TSH)-like activity of human chorionic gonadotrophin (hCG) which is secreted in large amounts by the molar vesicles. The diagnosis is suggested by the clinical findings and is confirmed by an ultrasound scan which will reveal no fetal parts but only a speckled or snowstorm appearance (Oats & Abraham 2004). Urinary or serum hCG levels wiil be high.

Treatment

Once the diagnosis of molar pregnancy is confirmed, the uterus must be completely evacuated at once. This is achieved by careful suction curettage (see Fig. 54.3). Uterine contractions may cause molar tissue to enter the circulation via the sinuses of the placental bed. These emboli may set up metastatic disease in other sites, commonly the lungs. Medical termination should therefore be avoided. Unless the woman is haemorrhaging, oxytocic drugs are withheld until the uterus has been surgically emptied. A Syntocinon infusion may then be used to maintain uterine contraction and haemostasis. The woman should be registered at a specialist follow-up centre in London, Sheffield or Dundee (RCOG 2004a).

After treatment for hydatidiform mole, careful observation is required as approximately 3% of these women will develop malignant trophoblastic disease (choriocarcinoma). Partial moles are less likely to become malignant but still require follow-up (Seckl et al 2000). Serum beta-hCG levels are monitored fortnightly until the values fall to within the normal range. Urine samples are then normally tested every 4 weeks until 1 year after evacuation. In the second year of follow-up, urinary hCG testing is carried out every 3 months.

If any molar tissue remains in the uterus, it will continue to grow and may invade the myometrium. Perforation of the uterine wall is then likely and this will cause major internal haemorrhage. Signs that the mole is continuing to grow are indicated by the persistence of high hCG levels 24 hours after uterine evacuation and high levels 1 month after treatment. If the serum or urinary hCG fails to return to normal levels within 6 months or begins to rise again, the woman is at risk of malignant trophoblastic disease.

The woman must avoid another pregnancy until she has been discharged from the follow-up programme. Use of the oral contraceptive pill increases the risk of the development of invasive disease and should therefore be avoided until hCG levels have been normal for three successive months.