This information refers to treatment of a first trimester miscarriage (up to 12 weeks gestation).
Definition of miscarriage
The majority of miscarriages occur before 12 weeks of pregnancy with less than 5% occurring after identification of a fetal heart on ultrasound scanning.
When a pregnancy is said to be no longer viable (not ongoing), it may be called a ‘missed miscarriage’ when the fetus is present but there is no heart beat or an ‘anembryonic pregnancy’ when there is no fetus in the developing gestational sac.
An incomplete miscarriage is when part of the pregnancy tissue has been expelled from the uterus and a complete miscarriage is when the entire pregnancy has been expelled.
Bleeding is common in early pregnancy and does not necessarily mean that the pregnancy has miscarried. Ultrasound scanning is required to confirm whether a pregnancy is ongoing or not.
Treatment options for first trimester miscarriages
Expectant management, as long as the woman is clinically stable, is a safe option to consider in a first trimester miscarriage and can avoid the need for surgery. However, the likelihood of spontaneous expulsion of the pregnancy declines rapidly after a week of expectant management and the emotional toll of prolonging the completion of the pregnancy loss can be significant. Women who have an incomplete miscarriage respond better to expectant management than those with a missed or an anembryonic pregnancy loss.
Risks of expectant management include a risk of incomplete miscarriage and the need for subsequent surgical or medical management and heavy bleeding and pain.
Misoprostol is a prostaglandin analogue that is licensed to be used in the treatment of peptic ulcers. It can be given orally, vaginally, rectally and sublingually. Misoprostol has the effect of inducing uterine contractions and softening the cervix and can be used for the treatment of incomplete, missed and anembryonic pregnancy loss.
Incomplete miscarriages can be managed with misoprostol with success rates of up to 99% whilst success rates in missed and anembryonic miscarriage are not as high and are said to be of the order of 60-83%.
The recommended dosage according to NICE guidelines is:
- Missed miscarriage: single dose of 800micrograms of misoprostol either vaginally or orally.
- Incomplete miscarriage: single dose of 600miscrograms either vaginally or orally
Risks of medical management using misoprostol include diarrhoea, vomiting, abdominal pain, fever and chills and incomplete miscarriage requiring a surgical procedure. Heavy bleeding can be experienced requiring admission to hospital in a small number of cases.
A surgical procedure was traditionally recommended to all women having a miscarriage and is certainly the right treatment for women who are experiencing very heavy and continuous bleeding, where there is suspected infection, where gestational trophoblastic disease (molar pregnancy) is suspected and where either expectant or medical treatment has failed.
A surgical procedure is always performed in a hospital environment either in theatre or a hospital outpatient setting and is usually performed under general anaesthetic although it can be done using local anaesthetic.
Surgical management is usually performed using electric vacuum aspiration with or without sharp curettage or less commonly using a manual vacuum aspiration.
Overall, surgical management is a more successful treatment than either expectant or medical management with respect to completion of the pregnancy loss and is associated with a shorter duration of bleeding and pain particularly the more advanced the pregnancy.
Risks of a surgical curettage include: trauma to the cervix, uterine perforation, development of intrauterine adhesions (Asherman’s syndrome) and retained products of conception. These are rare complications with surgical management overall being a safe and effective treatment of miscarriage.
Making an informed decision
Patients’ preference should be considered when deciding upon the management of miscarriage. It is important for women to be aware of the options available to them when managing their pregnancy loss so that they can make an informed decision on how they wish to proceed.