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30 July 2013

Clinical Update: Methods of termination for fetal anomaly

By Dr Richard Lyus, treatment doctor, British Pregnancy Advisory Service.

1) How many terminations for fetal anomaly are there in the UK?

In England and Wales, about 2,000 abortions for fetal anomaly are recorded each year, under Ground E. However, the real figure is higher than this. Some abortions undertaken in fetal anomaly cases may have another primary indication, such as concerns for a pregnant woman’s health, which means that the abortion is recorded under Ground C. According to 2011 Department of Health abortion statistics, of abortions carried out under Ground E, 1,054 were for congenital malformations; 890 were for chromosomal abnormalities, of which 512 were for Down’s syndrome; and 363 were for other conditions. (1)

Screening tests for Down’s Syndrome are offered at 11-14 weeks of pregnancy, and a detailed ultrasound scan of the fetus at 18-20 weeks’ gestation. As a result, most fetal abnormalities are not diagnosed until the second trimester. Most terminations take place before the 24-week ‘time limit’: in 2011, only 146 abortions were carried out over 24 weeks’ gestation. By law, abortions after 24 weeks must be undertaken in an NHS hospital and cannot be performed at BPAS.

2) For women seeking a termination, what options are available?

When fetal anomalies are diagnosed in the second trimester, there are two options for pregnancy termination. The first is medical induction of labour, typically using the progesterone antagonist mifepristone and prostaglandin analogues to induce uterine contractions and cause the passage of the fetus and placenta intact. This can be a lengthy process: the mifepristone is administered 48 hours before admission, and the induction can take up to 24 hours and may require further surgery to remove retained tissue. It will usually take place on a labour ward.

The second option is surgical abortion, which involves instrumental removal of the fetus and placenta in small pieces through an artificially dilated cervix, under appropriate anaesthesia, typically taking 10-15 minutes. This is done as an outpatient procedure (‘day surgery’), and does not usually require admission to hospital.

3) Which method is safer?

Department of Health (DH) data from England and Wales show that surgical abortion is 6-11 times safer than medical abortion in the second trimester. (1) While there are limitations to the complication statistics produced by the DH, the rates are in keeping with other reports, including randomised controlled trials, which show surgical abortion to be not only safer, but more effective, cheaper, quicker, preferred by women and associated with better emotional outcomes than medical abortion in the second trimester. The higher rate of complications with medical induction is largely due to the significant minority of women who require additional surgery to remove retained tissue. This can also result in bleeding requiring blood transfusion.

For example:

• A US study by Bryant et al published in 2011 compared the safety and effectiveness of dilation and evacuation (D&E) and labor-induction abortion performed for fetal anomalies or fetal death in the second trimester. The authors concluded that ‘dilation and evacuation is significantly safer and more effective than labor induction for second-trimester abortion for fetal indications’, and that ‘Women facing this difficult decision should be offered a choice of methods and be provided information about their comparative safety and effectiveness’. (2)

• A randomised controlled trial by Kelly et al in Britain comparing medical versus surgical termination of pregnancy at 13-20 weeks of gestation found that women found surgical termination less painful and more acceptable than medical termination. (3)

• A US literature review by Grossman et al on complications following second trimester surgical and medical abortion in 2008 concluded that ‘current evidence suggests that, given trained providers and where otherwise feasible, D&E is preferable to medical induction’. The authors recommended that a larger randomised controlled trial was needed, that ‘directly compares outcomes between the two methods, examines acceptability to women and explores clinicians’ perspectives on providing them.’(4)

• A US study by Whitley et al published in 2011 concluded that midtrimester D&E is associated with fewer complications than prostaglandin induction. (5)

4) Which method do women prefer?

In cases of termination for fetal anomaly, there are reasons why women might prefer either a surgical method, or medical induction. For example, some women may prefer to go through labour and delivery, and have an intact fetus that they can see and hold. Others may find a surgical procedure under general anaesthetic easier to cope with.

For second-trimester terminations in general, research evidence strongly suggests that women have a preference for surgical procedures. Indeed one US trial comparing the two methods was unable to proceed because so few patients were willing to be randomised to the medical induction arm. (6) Among the 18 participants enrolled, nine were randomised to treatment with mifepristone-misoprostol and 9 to D&E. Compared with D&E, mifepristone misoprostol abortion caused more pain and adverse events, although none was serious.

When the termination is undertaken for fetal anomaly, the key factor is women’s choice. In 2011, a qualitative study by Kerns et al of women terminating a pregnancy for fetal or maternal complications found that ‘Key themes that emerged from the interviews were valuing the ability to choose the method, and the importance of religious beliefs, abortion attitudes, and emotional coping style. Women’s preferences for a method were largely based on their individual emotional coping styles.’ (7) The lower acceptability rates of medical induction may be due to the fact that it takes significantly longer, is more painful and causes heavier bleeding. Some women may also find the experience of labour extremely distressing in these circumstances.

5) Which method do clinicians prefer?

DH data show that that approximately three-quarters of all abortions done in the second trimester for indications not related to fetal abnormality are done surgically. However, the proportion is dramatically different for those abortions undertaken because of a fetal abnormality: only 16% are performed surgically. (1, 8) There are a number of possible reasons for this disparity. Women will generally be diagnosed with fetal anomaly and managed in the NHS, where access to surgical abortion (especially D&E) is limited. (9) Another reason may be the perceived importance of delivering an intact fetus for post-mortem (PM) examination. However, there is a lack of clear guidance as to which abnormalities benefit from detail fetal PM. It is unlikely to be of any benefit in the majority of anomalies. (10)

Given the relatively small proportion of women who undergo surgical abortion for fetal anomaly, it has been hypothesised that clinicians have a bias against surgical abortion, despite it being safer and preferred by a majority of women. More research is needed to confirm if this is the case, and is so, why.

It is important that decision making about method of abortion for fetal anomaly should be shared between patients and clinicians, and both medical and surgical abortion should be offered wherever appropriate. However, the research is clear: surgical abortion is safer and preferred by most women. It is therefore incumbent upon clinicians and commissioners to better understand why so few women in the UK with fetal abnormality undergo surgical abortion. There may be multiple reasons, but if this disparity is due to clinicians’ bias against surgical abortion this would represent a serious contravention of the principles of medical ethics. (11)

Also read:

Second trimester abortion for fetal abnormality. Lyus R, Robson S, Parsons J, Fisher J, Cameron M. BMJ. 2013 Jul 3;347:f4165. doi: 10.1136/bmj.f4165.

References

(1) Abortion statistics for England and Wales 2011. Department of Health.

(2) Bryant AG, Grimes DA, Garrett JM, Stuart GS. Second-trimester abortion for fetal anomalies or fetal death: labor induction compared with dilation and evacuation. Obstetrics and Gynecology. 2011;117(4):788-92

(3) Kelly T, Suddes J, Howel D, Hewison J, Robson S. Comparing medical versus surgical termination of pregnancy at 13-20 weeks of gestation: a randomised controlled trial. BJOG. 2010;117(12):1512-20

(4) Grossman D, Blanchard K, Blumenthal P. Complications after second trimester surgical and medical abortion. Reproductive Health Matters. 2008;16 (31 Suppl):173-82

(5) Whitley KA, Trinchere K, Prutsman W, Quiñones JN, Rochon ML. Midtrimester dilation and evacuation versus prostaglandin induction: a comparison of composite outcomes. American Journal of Obstetrics and Gynecology. 2011;205(4):386

(6) Grimes DA, Smith MS, Witham AD. Mifepristone and misoprostol versus dilation and evacuation for midtrimester abortion: a pilot randomised controlled trial. BJOG. 2004 Feb;111(2):148-53

(7) Kerns J, Vanjani R, Freedman L, Meckstroth K, Drey EA, Steinauer J. Women’s decision making regarding choice of second trimester termination method for pregnancy complications. International Journal of Gynaecology and Obstetrics.2012;116(3):244-8

(8) Department of Health, personal communication November 2012

(9) Thomas J, Paranjothy S, Templeton A. An audit of the management of induced abortion in England and Wales. International Journal of Gynaecology and Obstetrics. 2003 Dec;83(3):327-34.

(10) Termination of Pregnancy for Fetal Abnormality in England, Scotland and Wales. Report of a working party. RCOG, 2010

(11) Grimes DA. The choice of second trimester abortion method: evolution, evidence and ethics. Reproductive Health Matters. 2008 May;16(31 Suppl):183-8.

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