In the UK, mifepristone in combination
with a PG analogue was licensed for the termination of pregnancy
up to9 weeks amenorrhoea in 1991, and since 1995 has also been available
for termination for pregnancy beyond 13 weeks.
University of Aberdeen has extensive experience of medical abortion
at all gestations. A consecutive series of 4132 women with pregnancies
of up to 63 days of amenorrhoea undergoing induced abortion were
studied between January 1994 and November, 2001. At these gestations,
women presenting for terminations were given a choice of medical
or surgical methods. The assessment of gestational age was based
on ultrasound measurement. Following appropriate counseling, each
woman received 200 mg mifepristone orally. A total of 2000 (48.4%)
women were included in the initial analysis using a single dose
of prostaglandin and 2132 (51.6%) women in the subsequent analysis,
since protocols were changed, using up to two doses of prostaglandin,
if required. If abortion failed to occur in 36 to 48 hrs, 800 µg
vaginal misoprostol was administered and the patient was observed
for 4 to 6 hours. If no products were expelled, then women in this
group received modified regime i.e. a second dose of misoprostol
400 µg vaginally or orally. All women were offered a follow-up
appointment within 2 weeks of the termination.
Of the 4132 women, 95 (2.3%) aborted within 48 hours of mifepristone
and a further 3942 (95.4%) achieved complete abortion following administration
of one or two doses of misoprostol. Thus, the overallcomplete abortion
rate was 97.7%. Induction abortion interval was 4.0 + 1.6 hours and
97% were managed as day cases. A total of 94 women (2.3%) required
surgical intervention of which 1.6% had surgical evacuation because
of incomplete abortion, 0.3% for missed abortion and 0.3% for continuing
pregnancy; 10 (0.2%) evacuations were required to achieve hemostasis.
Oxytocics at the time of abortion were required in 1%, blood transfusion
in 0.2%, unscheduled visit in 1.1% and antibiotic prescription in
2.7%. In patients who required one or two doses of misoprostol, the
complete abortion rates were 97.5% and 97.9%, incomplete abortion
1.8% and 2% and continuing pregnancy 0.6% and 0.1%. The failure rate
increased as the gestation increased. To conclude, mifepristone 200
mg in combination with one or two doses of vaginal misoprostol is
an effective regimen for early medical abortion. Addition of a second
dose of misoprostol reduces the ongoing pregnancy rates significantly
and abolishes the effects of increasing gestation on successful outcome.
In England and Wales, majority (72%) of abortions are carried out
at 9 to 13 weeks gestation, while in Scotland, about one-third of
all are carried out at 9 to 13 weeks. At present, surgical methods
(vacuum aspiration) are used at 10 to 13 weeks amenorrhoea, and
there is little published work on the use of medical methods (Ashok
et al, 1998).
A randomized controlled trial comparing medical abortion with vacuum
aspiration at gestations between 10 to 13 weeks was carried out
in 486 women at Aberdeen. The medical method (n=188) was mifepristone
200 mg followed by misoprostol up to 3 doses or surgery (n=180)
by vacuum aspiration under general anaesthesia. Outcome measures
included efficacy rates, medical complications within 8 weeks of
the procedure, patient preferences and acceptability.
Figure 2.4.1
|
Figure
2.4.2
|
In patients who underwent medical and surgical abortions, the complete
abortion rates were 95% and 98%, pelvic infection (8 weeks) was
4% and 8%, psychological morbidity (8 weeks) was 6% and 5%, pain
and bleeding (8 weeks) 3% and 4%, respectively. Thus, medical abortion
is as safe and effective as vacuum aspiration at 10 to 13 weeks
gestation and its introduction could have a considerable impact
on the provision of medical services, as well as increasing the
women’s choice of methods available.
Methods used for termination of second trimester pregnancy include
:-
• Hysterotomy (48% in 1968 – 9% in 1973, UK)
• Saline instillation (53% in 1974, US)
• Prostaglandin (increasing use during 1970’s)
• Dilatation and Evacuation (51% in 1978, US)
In a review of 1002 cases of second trimester abortion with mifepristone
200 mg orally and misoprostol vaginally, followed by 400 µg
oral misoprostol to a maximum of four doses, successful complete
abortion rate was 97.1%. Surgical evacuation was needed in 8.1%,
median induction abortion interval was 6.3 hours and 72.4% patients
were managed as day cases. Pretreatment with mifepristone leads
to a significant reduction in induction abortion interval (fig.
2.4.1). The success in this study was defined as abortion within
15 hours.
There is no significant difference in cumulative percentage of
women aborting.
The preferred regimen at Aberdeen is single dose mifepristone 200mg
followed by 800 µg misoprostol originally and a repeat dose
of 400 µg misoprostol 4 hours later. Bleeding requiring intervention
occurs in 1% cases and infective morbidity is less than 3%. |
