Late termination of pregnancy is a relatively rare procedure accounting for approximately 1% of all registered terminations in England and Wales; however, with improving detection rates for foetal anomalies, this number is increasing. Surgical dilation and evacuation (D&E) appears to be a safe and cost-effective procedure as long as the clinical expertise exists to provide this service. Medical termination appears equally safe and is best undertaken with the combined use of mifepristone and misoprostol. Foeticide, when required, should be performed from 22 weeks’ gestation using strong KCl administered either by cardiocentesis or by cordocentesis. All women should be offered a post-mortem and any other appropriate investigation to allow accurate counselling regarding future pregnancies. The issue of late selective foetal reduction for foetal abnormality is complicated by the need to balance the risks to the healthy co-twin of expectant management versus selective termination.
Incidence
Second-trimester abortion comprises 10–15% of the 42 million abortions that occur worldwide each year. According to surveillance data from the Center for Disease Control and Prevention (CDC), 12% of abortions occur at or after 13 weeks’ gestation, with 1.3% being performed from 21 weeks’ gestation. Induced abortion is one of the most commonly performed gynaecological procedures in Great Britain, with around 186 000 terminations performed annually in England and Wales and around 11 500 in Scotland. Termination of pregnancy for foetal anomalies constituted less than 1% of all registered termination during 2001 in England and Wales and is therefore a rare procedure, both in terms of the total number of pregnancies and the total number of abortions.
Ethics and the law
The ethics of termination of pregnancy covers many religious and social aspects of life, leading to highly emotional and heated public debate, an issue that is beyond the scope of this article. Termination of pregnancy is legal in Great Britain if two doctors decide in good faith that a particular pregnancy is associated with factors that satisfy one or more of five grounds specified in the Regulations of the Abortion Act and Section 37 of the Human Fertilisation and Embryology Act 1990. In England and Wales in 2002, the vast majority of abortions were undertaken under grounds C and D, with grounds A, B and E together accounting for just over 2% of abortions. Between 2000 and 2004, approximately 100 terminations per annum were carried out under ground E annually in UK beyond 24 weeks, making up ∼5% of all those conducted for foetal abnormality.
Ethics and the law
The ethics of termination of pregnancy covers many religious and social aspects of life, leading to highly emotional and heated public debate, an issue that is beyond the scope of this article. Termination of pregnancy is legal in Great Britain if two doctors decide in good faith that a particular pregnancy is associated with factors that satisfy one or more of five grounds specified in the Regulations of the Abortion Act and Section 37 of the Human Fertilisation and Embryology Act 1990. In England and Wales in 2002, the vast majority of abortions were undertaken under grounds C and D, with grounds A, B and E together accounting for just over 2% of abortions. Between 2000 and 2004, approximately 100 terminations per annum were carried out under ground E annually in UK beyond 24 weeks, making up ∼5% of all those conducted for foetal abnormality.
Definition of late termination
Abortion is defined as termination of pregnancy by any means before the foetus is viable. Viability is now considered to be reached at 24 weeks of gestation, as the Abortion Act infers in grounds C and D. To terminate the pregnancy after this gestation, the pregnancy must represent either a risk to the woman’s life or the foetus needs to have ‘a substantial risk’ of being ‘seriously handicapped’. Second or mid-trimester is a period that could range from 13 to 28 weeks’ gestation. In this review, late termination is defined as a termination performed after the 13th gestation week, irrespective of foetal viability.
Indications for late terminations
Advances in medical ultrasound technology and the introduction of routine prenatal screening allow the diagnosis of various foetal abnormalities (including structural, chromosomal and genetic) throughout the different stages of pregnancy. Antenatal detection of foetal malformations relies on accurate detection of the disorder from screening programmes. The Royal College of Obstetricians and Gynaecologists (RCOG) Working Party on Ultrasound Screening for Foetal Abnormalities and National Institutes for Clinical Excellence (NICE) Guidelines for Routine Antenatal Care state that pregnant women should routinely be offered an ultrasound scan to screen for structural anomalies, ideally between 18 and 21 weeks’ gestation. The detection rates for foetal malformations vary greatly with some abnormalities being diagnosed almost universally (e.g., anencephaly) and some malformations being diagnosed in less than 50% (e.g., congenital heart defects) of cases. In addition, some foetal malformations are not apparent at the 20-week anomaly scan but are more apparent at later gestations (e.g., hypoplastic left heart syndrome and cerebral ventriculomegaly). The incidence of foetal malformations has been evaluated from 17 European population-based registries of congenital malformations (EUROCAT) for the period 1995–1999. Although the overall prenatal detection rate for major foetal abnormality was 64%, just 68% of these occurred before 24 weeks of gestational age.
Because of the relatively high sensitivity of the anomaly scans, most late terminations are performed before 24 weeks gestation. The Cochrane Review on Ultrasonography after 24 weeks failed to demonstrate any evidence of reduced perinatal mortality, but this review was limited by a paucity of information on long-term substantive outcomes such as neurodevelopment. Screening for foetal structural abnormalities is mostly restricted to the options of continuing versus terminating the pregnancy when a diagnosis is made. Vaknin et al. reviewed all 84 late terminations performed in a referral centre for foetal abnormalities, diagnosed before or after 23 weeks. Interestingly, the incidence of structural abnormalities (excluding genetic problems or infections) diagnosed after 23 weeks was significantly increased for cardiac and chest anomalies. By contrast, face, neck and gastrointestinal tract anomalies were diagnosed more frequently before 23 weeks.
Methods
Termination of pregnancies in the second trimester can be performed either surgically or medically. Dilation and evacuation (D&E) has become the preferred surgical technique over hysterotomy and hysterectomy because of its relative safety. Early induction methods, such as intra-amniotic instillation of hypertonic solutions and prostaglandin F2α, have largely been replaced by the use of oral and/or vaginal prostaglandin analogues with or without anti-progestin (mifepristone) priming. D&E is used for 75% of abortions performed after 13 weeks in England and Wales. A recent Cochrane review concluded that D&E is preferable to prostaglandin F2α instillation. However, the meta-analysis was based mainly on one large randomised controlled trial (RCT), with the second study having very low recruitment. A lower incidence of fever, haemorrhage, cervicovaginal trauma and prostaglandin reaction was noted in the D&E group. Regardless of the chosen method for termination of pregnancy, infection prophylaxis should be undertaken with antibiotic regimens such as metronidazole with doxycycline or azithromycin.
Medical methods
Regimes for medical termination usually include anti-progestins (mifepristone) together with prostaglandin analogues (misoprostol and gemeprost). Mifepristone is used for pre-treatment prior to the use of prostaglandins to reduce the induction-to-abortion interval. The combined use of mifepristone and gemeprost has been shown to be more effective than placebo, ‘laminaria’, Dilapan with Sulprostone and prostaglandins in RCT studies. Mifepristone can be used equally effectively with either gemeprost or misoprostol, as long as there is a 36-h interval between adminstration. In three RCTs, there were no differences in interval abortion rate and side effects between association of mifepristone plus misoprostol and mifepristone plus gemeprost.
Misoprostol can be administered either vaginally or orally. The oral route appeared to be preferred by women despite the higher incidence of minor side effects. There are no substantial differences in the interval abortion rate and failure in the vaginal versus oral groups. The vaginal route has also been compared with sublingual administration. Both routes appear to be equally effective; however, women reported a preference for avoiding the vaginal route. Little or no differences are also found with different dosage regimens for sublingual or vaginal treatments ( Practice Point Table 1 ).
- •
Regimen 1. Mifepristone 200 mg orally, followed 36–48 h later by misoprostol 800 μg vaginally, then misoprostol 400 μg orally, 3-hourly, to a maximum of four oral doses.
- •
Regimen 2. Mifepristone (600 mg orally) followed by gemeprost (1 mg vaginally) 36–48 h later given 3-hourly up to five doses.
Surgical methods
RCOG guidelines for the termination of pregnancy advocate suction termination for an early second trimester abortion (below 15 weeks) and for gestations above 15 weeks, surgical abortion by D&E appears safe and effective when undertaken by specialist trained practitioners. Cervical preparation is beneficial prior to surgical abortion and should be routinely used in the second trimester. Natural and synthetic cervical osmotic dilators, such as laminaria, Dilapan and Lamicel, have been used for many years and are known to be safe and effective for cervical preparation prior to the surgical termination of pregnancy. Dilapan appears to be more effective than all the other osmotic cervical dilators. Only one RCT compared misoprostol to laminaria for preparing the cervix before 16 weeks and reported slightly longer procedures in the misoprostol group. RCOG guidelines advocate three medical regimens for cervical preparing including misoprostol, gemeprost and mifepristone ( Practice Point 2 ). The most common method of D&E involves the removal of the foetus through the prepared cervix using strong, elongated extraction forceps. Another variant is known as intact dilatation and extraction (D&X), where wide cervical dilatation is followed by an assisted breech delivery of the foetus. The method of choice would depend on the training and experience of the operators involved.
- •
Misoprostol: 400 μg vaginally, 3 h prior to surgery.
- •
Mifepristone: 600 mg orally, 36–48 h prior to surgery.
- •
Gemeprost: 1 mg vaginally, 3 h prior to surgery.
Special clinical circumstances
Placenta praevia
Observational studies do not report any increased mortality rate in women with placenta praevia, who underwent late termination. There are no differences in the effectiveness of surgical or medical methods, with only one woman in a large retrospective series requiring blood transfusion. The largest series consists only 20 cases, and the only finding was an increased blood loss, without any adjunctive post-termination transfusion.
Prior caesarean section
Prior caesarean section is probably the most significant risk factor for uterine rupture. Uterine rupture is extremely uncommon with a reported prevalence of <1% in late terminations in women with previous caesarean section. The number of women with caesarean scars admitted for late second-trimester pregnancy termination will increase in the future, and for this reason, women should be warned about the potential risk of uterine rupture.
Foeticide
Abortion should not result in the birth of a living child that then dies for reasons other than the severe abnormality for which the abortion was performed. A neonatal death, occurring after the live birth from a termination of pregnancy, should be avoided. The purpose of the Abortion Act 1967 is to protect women and their doctors from prosecution for illegal abortion under the Offence Against the Person Act 1961. Any deliberate act causing the child’s death constitutes a murder. RCOG guidance is clear in its direction to ensure that foetuses are not born alive, listing procedures that will ensure foetal death prior to termination. For all terminations at gestational age of more than 21 weeks and 6 days, the method chosen should ensure that the foetus is born dead and the foeticide must be conducted by a trained doctor in foetal medicine. On the basis of publicly available data, it is difficult to establish how many foeticides are performed annually for this specific purpose, but a conservative estimate would be between 300 and 600. The RCOG recommend the use of an intracardiac injection of KCl followed by the confirmation of foetal asystole after 30–60 min.
Other methods include the injection of lidocaine, digoxin or intra-amniotic prostaglandin and hypertonic urea and saline solution into the foetal circulation. There are no RCTs reported on foeticide techniques; however, from observational studies, methods such as cardiocentesis and cordocentesis are safe for the mother and effective in achieving foetal asystole. In a retrospective series, KCl has also been associated with a significant reduction in prostaglandin requirement for mid-trimester medical abortion, compared with similar procedures conducted without foeticide. To minimise foetal movements induced by cerebral asphyxia, diazepam can be administered prior to the use of KCl. Other methods such as administration of digoxin, sulfentanil/lidocaine by cordocentesis or cardiac tamponade by pericardial injection of saline should be avoided because of the limited number of reported cases and the relatively high failure rate.
Costs
Cowett et al. developed a cost-effectiveness model to compare D&E and medical termination. D&E is less expensive and more effective than misoprostol induction of labour for second-trimester termination. Despite this finding, it is clear that the decision on whether to undertake surgical or medical procedures in the second trimester must be based upon the clinical expertise available within individual care settings.
Post-termination examination
Medeira and co-workers carried out post-mortem examinations on 343 foetuses that had undergone mid-trimester abortion for abnormality. In more than 40% of cases, additional information was obtained from the post-mortem that was not evident from the prenatal diagnosis by ultrasound or invasive testing. Although the additional information would not have changed the prognosis or the management of the pregnancy to termination, in a significant number of cases, valuable information was obtained regarding the prognosis for future pregnancies. It is therefore very important to emphasise the importance of post-mortem examination to the parents.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
