Intended for healthcare professionals

Analysis

Second trimester abortion for fetal abnormality

BMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f4165 (Published 03 July 2013) Cite this as: BMJ 2013;347:f4165
  1. Richard Lyus, doctor 1,
  2. Stephen Robson, professor of fetal medicine 2,
  3. John Parsons, retired consultant gynaecologist 1,
  4. Jane Fisher, director 3,
  5. Martin Cameron, consultant in fetal medicine4
  1. 1British Pregnancy Advisory Service, Richmond TW1 2AR, UK
  2. 2Newcastle University, Newcastle upon Tyne, UK
  3. 3Antenatal Results and Choices, London, UK
  4. 4Norfolk and Norwich University Hospitals, Norwich, UK
  1. Correspondence to: R Lyus Richard.lyus{at}bpas.org
  • Accepted 30 May 2013

Although surgical abortion is safer and preferred by many women, most abortions for fetal abnormality in England and Wales are performed medically. Richard Lyus and colleagues call for an end to this disparity

Antenatal testing for fetal abnormalities is offered to all pregnant women in the United Kingdom, but most abnormalities are not detected until after 14 weeks of pregnancy. When an abnormality is detected a woman may choose abortion, which can be performed by either surgical or medical methods. Surgery is safer and preferred by women in the second trimester. Despite this, most abortions in the UK for fetal abnormality are medically induced. This disparity between evidence and practice needs to be investigated to ensure all women choosing abortion have access to the best available treatments.

Screening for abnormalities and options for abortion

Screening for fetal abnormalities using ultrasonography or biochemical tests allows patients and clinicians to plan appropriately for the delivery or consider the option of abortion. Each year in England and Wales at least 2000 abortions for fetal abnormality are recorded. About a third of these cases are for chromosomal abnormalities, of which trisomy 21 (Down’s syndrome) is the most common, and half are for structural abnormalities detected by ultrasonography, mainly affecting the nervous or musculoskeletal system.1 Screening tests for Down’s syndrome are offered at 11-14 weeks of pregnancy, and a detailed ultrasound examination of the fetus at 18-20 weeks. As a result, most fetal abnormalities are not diagnosed until the second trimester, when there are two options for abortion. Medical abortion, typically with the progesterone antagonist mifepristone and prostaglandin analogues, can take up to 48 hours and may require further surgery to remove retained tissue. The second option is surgical abortion (dilation and evacuation), which typically takes 10-15 minutes.

Evidence for choosing surgical abortion

Department of Health data on complications show that surgical abortion is 6-11 times safer than medical abortion in the second trimester in England and Wales.1 Although there are limitations to the statistics, the complication 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.2 3 4 5 6 7 The difference in complications is largely due to the higher rates of retained tissue after medical abortion; the reported rates of this complication vary from 3% to 50%.8 This variation is probably explained by differences in how long clinicians are willing to wait for the placenta to pass spontaneously before intervening.

In one retrospective study of 220 women, 22% of 126 women having a medical induction had retained tissue versus only 2% of 94 having dilation and evacuation (P=0.01). Furthermore, median length of stay was shorter in the surgical group (5.7 hours versus 28.4 hours, P<0.001).4 A UK based randomised controlled trial of 122 women at 13-20 weeks’ gestation concluded that women found surgical abortion more acceptable: 100% of women in the surgical group said they would opt for the same procedure again versus 53% in the medical induction group (P≤0.001). In addition, none of the women in the surgical group found the procedure worse than expected compared with 53% of women in the medical induction group (P=0.001). Women in the medical induction group experienced more bleeding, more pain on the day of the procedure, and more days of pain. They also had poorer scores on the Impact of Event scale (a measure of distress) two weeks after the procedure. Furthermore, of the 107 women who declined to participate in the study, 67% expressed a preference for surgery.2 A trial in the United States comparing the two methods was unable to proceed because so few patients were willing to be randomised to medical abortion.7

The recorded benefits and preferences apply equally when the abortion is for fetal anomaly, and its use in this setting has been described in the literature for many years.9 In one retrospective cohort study of women having an abortion for fetal abnormality or in-utero fetal death, 32 of 136 women undergoing medical abortion (24%) experienced one or more complications compared with nine of 263 women (3%) having surgical removal. The adjusted risk ratio for labour induction was 8.5 (95% confidence interval 3.7 to 19.8) compared with dilation and evacuation.5 A qualitative study examined themes emerging from interviews with 21 women having abortions for complications of pregnancy. A key theme was the value women placed on the ability to choose the method of abortion; 13 (62%) chose surgical abortion while 8 (38%) chose medical abortion.10

Some clinicians believe that although surgical abortion has a lower rate of complications, those that do occur are more severe. However, medical induction is also associated with rare and serious complications, including uterine rupture and haemorrhage.8 A further concern expressed by clinicians is that that surgical abortion may affect subsequent pregnancies. However, three studies have looked specifically at subsequent pregnancy morbidity after dilation and evacuation and found no significant association with adverse pregnancy outcomes.11 12 13

Reasons for lack of use

Given this evidence it would be expected that most women having a second trimester abortion would choose the surgical option, regardless of the indication. Indeed, Department of Health data show that about three quarters of all abortions in the second trimester for indications not related to fetal abnormality are done surgically.1 However, only 16% of abortions for fetal abnormality are performed surgically (Department of Health, personal communication). Similar patterns have been reported in other European countries.14 15

Why do most women having an abortion for fetal abnormality undergo a less safe procedure that takes longer and may be more unpleasant for the patient? Crucially, these women will generally be diagnosed and managed in the NHS, where access to surgical abortion, especially dilation and evacuation, is extremely limited. Most NHS units provide surgical abortion only in the first trimester,16 with second trimester surgical abortions performed mainly by independent sector providers. Lack of provision in NHS settings means trainees are not exposed to surgical abortion services, perpetuating the situation.

An additional consideration is the perceived importance of delivery of an intact fetus for postmortem examination. Although a fetal postmortem may yield new information about risk of recurrence or management of a subsequent pregnancy, there is no clear guidance about when it is useful. It is unlikely to be of any benefit in confirmed cases of common karyotypic abnormalities, such as trisomies and 45X, which represent roughly one third of all abortions for fetal anomaly.17 In fetuses with a normal karyotype but with structural abnormalities identified by ultrasonography, fetal postmortem may be useful. However, a recent report from an experienced fetal medicine centre found that a postmortem provided supplemental information in only 16% of such cases. Furthermore, this information altered patient counselling regarding future pregnancies in less than 1% of cases.18

An additional but important factor is the personal preference of clinicians. Some staff find surgical abortion distasteful and emotionally challenging, and those who do provide it may be stigmatised.19 20 As a result, many doctors are reluctant to offer it. However, given that surgical abortion is a superior procedure, failing to facilitate referral for these reasons contravenes the principles of medical ethics.21 The situation in the UK and Europe is in stark contrast to the United States, where dilation and evacuation is the primary method of midtrimester abortion for any indication, and one third of maternal-fetal medicine specialists provide dilation and evacuation.22

Facilitating choice

Decision making about method of abortion for fetal abnormality should be shared; patients need to understand the risks and benefits of each option, and clinicians need to be empathetic to their preferences. When appropriate both medical and surgical abortion should be offered—women value choice10 and the Royal College of Obstetricians and Gynaecologists supports it.23 Given the well established and growing body of evidence demonstrating the superiority of surgical abortion, commissioners, educators, and clinicians have a duty to ensure that women are able to access this option, either by addressing the lack of NHS based providers or by ensuring access to external providers. It is also important that general practitioners are able to refer outside their area when women request dilation and evacuation but it is not available locally. All women should have access to the best available care, whatever the reason for their abortion and wherever their care is provided.

Notes

Cite this as: BMJ 2013;346:f4165

Footnotes

  • Contributors and sources: This article arose from work led by Antenatal Results and Choices as part of a working party on termination of pregnancy for fetal abnormality. RL prepared the manuscript and all authors contributed to revisions.

  • Competing interests: All authors have read and understood the BMJ policy on declaration of interests and have no relevant interests to declare.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

References

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