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
Aetiology and Pathogenesis
Clinical Profile
History
Examination
Investigations
Treatment
Medical
Surgical
Complications for Both Medical and Surgical Termination of Pregnancy
Prognosis
Definition
Therapeutic termination of pregnancy is defined as the use of an instrument or a hormone or chemical to abort a pregnancy. This is also known as a therapeutic abortion.
Incidence
TOP is a common procedure, with nearly 200,000 therapeutic abortions performed in the UK in 2011. It is not uncommon for women to have more than one abortion- more than one third of the women treated in 2011 had had a previous abortion.
Aetiology and Pathogenesis
There are two separate “types of reasons” for a request for TOP:
· Abnormality of the foetus – e.g. chromosomal abnormality. This is not preventable, and with the recent advances in antenatal diagnosis, more abnormalities will be diagnosed in the early stages of pregnancy, providing the option for TOP to prevent the birth of an affected child.
· The woman feels that she cannot continue with the pregnancy for psychological reasons. The most common reason for this is that the pregnancy was not planned.
This might occur because:
· No contraception was used or the method of contraception failed.
· The efficacy rate of any contraceptive choice depends on method effectiveness, with perfect use and method effectiveness with typical use (that is the ability to use the method according to instructions).
Clinical Profile
History
When did the woman have her last normal menstrual period (LNPM)?
· Were her cycles regular? (the approximate date of conception, and therefore the estimation of gestation is more reliable if cycles were regular)
The use of previous contraception should be documented. This is not to apportion any blame, but to ensure the provision of a reliable method of contraception for the future.
Part of the consultation for a TOP should include the provision of ongoing/future contraception to minimise the risk of a further unplanned pregnancy (see Chap. 15).
Any medical factors, which may effect whether a medical or surgical method is used, to terminate the pregnancy should be recorded.
A VTE risk assessment should be offered.
Examination
Routine abdominal, speculum and bimanual examination should still be undertaken, but has been superceded by the use of U/S as a clinical tool.
Investigations
· Ultrasound: Gestation is best assessed using ultrasound. This is most commonly via the transvaginal route, but this does depend on dates.
· Screening for blood group, rhesus factor, blood borne viruses, including syphilis and HIV and also screening for chlamydia, and gonorrhea should be offered routinely to all women.
· For women with haematological disorders, a haemoglobin estimation and haemoglobinopathy screening should be undertaken.
· Opportunistic cervical screening can be offered, if appropriate within a screening programme.
Treatment
Medical
Hormonal
Medical termination of a pregnancy is a licensed option up to 63 days gestation. The use of Mifepristone 200 mg, followed by misoprostol, 800 mg (delivered either vaginally or sublingually 24–48 h later), is a safe and effective method of terminating an unplanned pregnancy. The RCOG clinical practice guidelines recommend antibiotic prophylaxis for medical abortion.
Contraindications to medical abortion are few.
Absolute contraindications include:
· known or suspected ectopic pregnancy
· previous allergic reaction to one of the drugs
· inherited porphyria
· chronic adrenal failure
· coagulation disorder/ treatment
Caution is required if the woman:
· is on corticosteroid therapy
· has severe anemia
· has pre-existing heart disease or cardiovascular risk factors
· has an IUD in situ
Surgical
Manual Vacuum Aspiration: Procedure Performed Under Local Anaesthetic
· Following an initial consultation, determining that the woman/couple are unable to continue with the pregnancy, analgesia is administered.
· There are a number of different options, but the following provides good pain relief: Diclofenac delivered rectally in a dose of 100 mg
· The cervix is then prepared using the following regime:
· Misprostol 400 mg sublingually or intravaginally
· Instillagel via instillaquill – provides fundal pain relief and separates the gestation sac from the uterine wall
· Three percent scandanest injected at 12 o’clock, 3 o’clock and 9 o’ clock (cervical block)
· Antibiotic prophylaxis is provided in the form of:
· Metronidazole 1 G stat delivered rectally
· Azithromycin 1 G stat orally
To reduce the risk of vomiting an antiemetic can be provided.
The cervix can then be gently dilated to minimise the risk of trauma, bleeding, retained tissue and infection.
Manual vacuum aspiration (MVA) can be used up to 13 weeks gestation dependent upon the views of the provider.
A hollow tube is inserted into the uterus, through the cervix, with suction being applied via a syringe, to evacuate the products of conception.
Surgical Termination (STOP) Under General Anaesthesia
Surgical termination (STOP) under general anaesthesia can be performed up to 24 weeks gestation. However procedures undertaken at later gestations tend to be done in specialist centres under ultrasound control.
STOP up to 14 weeks gestation is similar to MVA, but it is necessary to identify body parts e.g. skull to ensure that the procedure is complete.
Complications for Both Medical and Surgical Termination of Pregnancy
Haemorrhage (blood loss greater than 500 ml or bleeding requiring transfusion). Fewer than 1 % of procedures are complicated by haemorrhage. The risk is lower at earlier gestation.
Blood loss is less with local anaesthesia compared to general anaesthesia. Prolonged or heavier bleeding than experienced during menstruation is an expected effect of medical abortion.
Injury to the cervix is thought to occur in less than 0.2 % of cases due to the current practice of cervical preparation.
Uterine perforation: Reported rates are about 1:500. The risks are increased in higher parity and higher gestation and as with cervical injury, and are reduced by cervical preparation and operator experience.
Continuing pregnancy: this is about 1:500 after surgical TOP and the risk is greatest in very early procedures (gestation under 7 weeks), higher parity, multiple pregnancy, uterine abnormality, the use of a narrow cannula relative to gestational age and operator inexperience. In 0.5–1 % of women having a medical termination, treatment fails and the pregnancy continues.
Retained products: The incidence of this for 1st trimester surgical procedures has been reported at 1.8 %, less than for medical procedures at the same gestation. This can be tissue or blood clot. Two to five percent of women undergoing medical termination will require further medical treatment or surgery for incomplete abortion, to terminate a continuing pregnancy, or to control bleeding.
Gastrointestinal side effects. The side effects of medical TOP include gastrointestinal side effects such as nausea, stomach cramps, vomiting and diarrhoea.
Upper genital tract infection: is a recognised complication of surgical abortion (10 % of cases) and is associated with the presence of organisms in the genital tract, both sexually transmitted (e.g. Chlamydia and Gonorrhoea) and non-sexually transmitted infections (e.g. beta haemolytic streptococcus). Routine prophylactic microbial therapy should be considered in all women undergoing surgical TOP. Infection is a less common complication after medical TOP, although routine antibiotics are still recommended by RCOG in the UK, but not in other countries.
Future reproductive health: There is a reported increased risk of pre-term birth post surgical abortion, with this risk increasing for repeated abortions. There may be similar risks with surgical management of miscarriage.
Mental health: Many women undergoing an abortion by any method will suffer short term emotional distress tempered with feelings of relief. The fact that a pregnancy was unwanted is associated with an increased risk of mental health problems, irrespective of whether the woman has an abortion, or gives birth, and the most reliable predictor of post-abortion mental health problems is having a history of pre-existing mental health problems. If a woman has a negative attitude towards abortion, shows a negative emotional reaction to the abortion, or is experiencing stressful life events, professional support should be offered.
Prognosis
There is no proven association between the following outcomes and surgical termination: breast cancer, placenta praevia, subfertility, ectopic pregnancy or miscarriage.
It is essential to provide effective contraception before the patient is discharged to reduce the risk of a further unplanned pregnancy occurring.