19 January 2012

Clinical Update: Feticide

By Patricia A. Lohr, Medical Director, BPAS.

Q) What is feticide?

From a medical perspective, this term refers to modalities to induce fetal demise (1). Feticide is most commonly used for selective termination of higher order gestations to twins or singletons. It is also used by some providers before medical and surgical abortion in the second and third trimesters to avoid signs of life at induction or in the belief that it makes the procedure easier and safer. Several methods have been described including intra-cardiac injection of potassium chloride, intra-amniotic injection of digoxin, and transection of the umbilical cord (2). Older methods of medical abortion employed instillation of hyperosmolar solutions such as urea, which also variably induced fetal demise.

Q) When is feticide typically used in the abortion process?

In Britain, the Royal College of Obstetricians and Gynaecologists (RCOG) has made specific recommendations about the use of feticide before medical abortion in cases of fetal abnormality (3). Its recommendations have also been applied to medical abortions for other indications (4). According to the RCOG, because the rare likelihood of a live birth increases from 21+6 weeks of gestation, feticide should be routinely offered after this gestational age to avoid this possibility. The RCOG recommends the use of intra-cardiac potassium chloride to ensure fetal asystole, which can be observed ultrasonographically typically within minutes after injection.

The usefulness of feticide before dilatation and evacuation (D&E), the commonest method of surgical abortion in the second trimester, remains a matter of debate. Cervical preparation before D&E usually occurs in the 24-48 hours before surgical evacuation and extra-mural deliveries, although rare, have been reported. Induction of fetal demise in these cases would avoid the potential for a live birth. However, advocates of feticide typically propose that the maceration of the fetus which occurs as a result of demise is beneficial because it leads to an easier, faster and safer surgical evacuation (5).

The only randomised trial comparing feticide to placebo evaluated intraamniotic digoxin and used procedure duration as a proxy for ease of abortion. With 1mg intra-amniotic digoxin, there was no difference in procedure time (p=0.60) or difficulty as reported by the surgeon (p=0.64) (6). Although the study was not designed to assess clinical outcomes, there were no differences in estimated blood loss, pain scores or complications between the groups. There are no similar studies of potassium chloride or other methods of feticide.

Q) What are the clinical skills required to administer feticide?

Most feticidal procedures are performed by intra-cardiac or intra-amniotic injections. Ultrasound evaluation prior to either allows confirmation of gestational age, evaluation of amniotic fluid level, fetal position, and placental location. Continuous ultrasound guidance is not necessary for intra-amniotic injections as confirmation of location of the needle can be assessed by drawing up a small amount of amniotic fluid into a syringe before injection of the medication. Intra-fetal or intra-cardiac injection, however, requires a greater degree of precision in needle positioning and continuous ultrasound guidance is usually employed. Ultrasound is also useful to confirm fetal asystole following potassium chloride injection.

Q) What are the advantages of using feticide from a clinical point of view?

There is some limited evidence that induced fetal demise before a medical abortion shortens the interval been the onset of the induction and expulsion of the fetus (7). In the setting of placenta praevia, bleeding may be less when feticide has been administered prior to a medical abortion (8). These effects still require testing in the context of larger, randomised trials. The randomised trial of digoxin before D&E at 20-24 weeks gestation by Jackson et al (6) reported that 92% of participants expressed a strong preference for fetal demise before the abortion. However, of those, 29% believed the injection would make the procedure easier and 19% less painful for the woman having the abortion, neither of which were proven by this study.

Q) And the disadvantages?

Extra-mural delivery of the fetus can occur in the interval between administration of feticide and initiation of a medical or surgical abortion (2). Although signs of life are avoided this is distressing and, in the case of a planned D&E, not the outcome the woman desired. Potential complications include injection site pain, amnionitis, or sepsis. Digoxin is associated with vomiting as a common side effect. One case report of a maternal cardiac arrest has been reported following potassium chloride injection (9).

Q) What would you recommend as best practice in the use of feticide?

There is currently no evidence to support the use of digoxin to facilitate increased safety with dilatation and evacuation. There is, however, evidence that its administration has the potential to cause harm (e.g., infection, vomiting, extra-mural delivery). It has recently been argued that digoxin feticide before D&E should only be provided in the context of a clinical trial aimed at assessing its benefits (10). At BPAS, we routinely perform intra-cardiac potassium chloride injections before D&E at 22+0 weeks and greater. We regularly review complications with all of our procedures and have found that, empirically, this practice is associated with an extremely low rate of complications. However, it is unknown whether it is the feticide or some other aspect of our service delivery which leads to such a strong safety profile. Ideally, this practice should be studied in a randomised trial as well.

At present, the RCOG makes a strong recommendation for the routine offer of feticide before later medical abortions, which is centred around the avoidance of resuscitation that is counter to the objective of terminating a pregnancy. Whether the balance of risks and benefits sways toward fetcide from a clinical perspective remains unclear. In addition, little is known about how patients feel about undergoing this invasive procedure which may, in and of itself, be distressing. Best practice at this stage would be to call for more and better research on the use of feticide.

Read all Patricia Lohr’s Clinical Update columns here.

References

(1) R.H. Graham et al. Understanding feticide: An analytic review. Social Science & Medicine. 2008; 66:289–300
(2) Diedrich J, Drey E; Society of Family Planning. Induction of fetal demise before abortion. Contraception. 2010 Jun;81(6):462-73.
(3) RCOG. Termination of Pregnancy for Fetal Abnormality in England, Scotland and Wales. London: RCOG, 2010.
(4) RCOG. The Care of Women Requesting Induced Abortion: Evidence-based Clinical Guideline Number 7. London: RCOG, 23 November 2011
(5) Maureen Paul, Steve Lichtenberg, Lynn Borgatta, David A. Grimes, Philip G. Stubblefield, Mitchell D. Creinin, eds. Management of Unintended and Abnormal Pregnancy: Comprehensive Abortion Care. Chichester, W. Surrey, UK: Wiley-Blackwell, 2009.
(6) Jackson RA, et al. Digoxin to facilitate late second-trimester abortion: a randomized, masked, placebo-controlled trial. Obstetrics and Gynecology. 2001;97:471–476
(7) Elimian A, Verma U, Tejani N. Effect of causing fetal cardiac asystole on second-trimester abortion. Obstetrics and Gynecology. 1999;94:139–141.
(8) Ruano R, et al. Second- and third-trimester therapeutic terminations of pregnancy in cases with complete placenta previa—does feticide decrease postdelivery maternal hemorrhage?. Fetal Diagnosis and Therapy. 2004;19:475–478.
(9) Coke GA, et al. Maternal cardiac arrest associated with attempted fetal injection of potassium chloride. International Journal of Obstetric Anesthesia. 2004;13:287–290
(10) Grimes DA, Stuart GS, Raymond EG. Feticidal digoxin injection before dilation and evacuation abortion: Evidence and ethics. Contraception. 2011 May 26. [Epub ahead of print]