Author Information
Desale S*, Gupta AS**.
(* Fourth Year Resident, **
Professor, department of Obstetrics and Gynecology, Seth GS Medical College
& KEM Hospital, Mumbai, India)
Abstract
A case report of first-trimester Cesarean scar pregnancy treated with systemic
Methotrexate (MTX) followed by oral Mifepristone therapy is presented. It is the rarest kind of ectopic
pregnancy and may lead to severe life threatening complications such as uterine
rupture and severe hemorrhage or may have adverse effect on future fertility.
Hence it is important to have early and accurate diagnosis to avoid
complications and preserve fertility.
Introduction
Ectopic pregnancy is an
important cause of maternal morbidity and mortality. Of all reported
pregnancies 1 to 2% are ectopic, which include the cesarean / hysterotomy scar
ectopic pregnancy whose incidence is about 6.1% of all ectopic pregnancies.[1]
Cesarean scar pregnancy is a rare type of ectopic pregnancy defined as a
gestation completely surrounded by myometrium and fibrous tissue of previous
scar, separate from endometrial and endocervical cavities. It occurs when
pregnancy implants in the area of the previous cesarean scar. Presence of
microscopic tracts from the scar site in the cavity into the myometrium allows
the blastocyst to implant wholly within the myometrium.[2] Treatment
includes surgical and medical therapy with Methotrexate, or Mifepristone.
Case Report
A 35 year old G3P1L1A1
at 5.3 weeks of gestation was referred from a private hospital with the
diagnosis of cesarean scar pregnancy. At presentation the patient had no complaints of abdominal pain, vaginal
bleeding, or syncopal attack. Her past obstetric history included
preterm lower segment cesarean sections done 13 years back and a spontaneously abortion at 2 months of gestation 4 years
back. Check curettage was not done. On examination vital parameters were
stable. Abdomen was soft; there was no guarding, rigidity or tenderness on
palpation. There was a Pfannenstiel scar. On speculum examination no bleeding
was seen. Her serological and biochemical
preoperative investigations were done. Hemoglobin was 13.1 g/dL.
All other investigations were in their normal range. Ultrasonography (USG) revealed
a gestational sac with yolk sac and peripheral
ring vascularity at the previous
scar site. Mean sac diameter was 9 mm corresponding to 5.5 weeks of
gestation. No fetal pole was seen. Endometrial and endocervical cavities were empty and both ovaries were normal. Endometrial thickness was 7 mm.
Figure 1. Transabdominal USG image of scar ectopic
pregnancy; gs and thick arrow: gestational sac, ut: uterus. Thin arrow the scar
of LSCS (anterior myometrium); green line posterior part of the anterior wall
myometrium.
Figure 2. Transabdominal
USG image of scar ectopic pregnancy; arrow mark: gestational sac.
The serum level of ß-HCG
on day 0 was 4309 mIU/mL. Since the patient was stable option for medical
treatment was taken. Injection Methotrexate 0.5mg/m2 , total dose of
80 mg was given intramuscularly. The patient was followed up on day 9 with
serum β HCG. The serum β HCG increased to 18,223 mIU/mL. USG on day 11 showed
gestational sac diameter had increased to
1 cm corresponding to 6.2 weeks and yolk sac was present. In view of
increase in serum βhCG level and USG finding, tablet Mifepristone 200 mg was
given orally. The patient further followed up on day 15 with serum βhCG which
was 12,168 mIU/mL and on day 30 was 2264 mIU/mL. She had her normal menstrual
cycle on day 34. On day 54 serum βhCG was 387 mIU/mL. USG reported increase in
gestational sac diameter to 31 mm , irregular and without any yolk sac or fetal
pole in anterior myometrium as seen in Figure 3. The patient remained
hemodynamically stable throughout follow up.
Figure 3. Post treatment
transvaginal USG. gs: irregular gestational sac; b: empty bladder; A is myometrium anterior to sac and P is myometrium posterior to gestational sac
Figure 4. The decreasing trend of serum β HCG after Methotrexate followed by Mifepristone
treatment.
Discussion
Cesarean scar ectopic
pregnancy is very rare condition with increasing trend of incidence.[3]
This is because of increasing rate of cesarean section and newer advances of
diagnostic technology. As the cesarean scar ectopic pregnancy is very rare,
there are no ideal management options available. The treatment options depend
on the patient’s hemodynamic condition,
severity of vaginal bleeding, gestational age, βhCG levels, demonstration of
fetal cardiac activity, need for future childbearing, and the available
infrastructure and expertise. A patient with uncontrolled bleeding and/or
uterine rupture usually requires surgical management. Surgical management
includes conservative and radical procedures. The conservative procedures
include evacuation of the pregnancy or trophoblastic tissue, wedge resection
and repair of the scar either by laparotomy or laparoscopy; bilateral ligation
of anterior division of iliac artery and dilatation and curettage.[3]
A radical procedure like hysterectomy is done in patients with uterine rupture
not willing for conservation of uterus or having uncontrolled bleeding. Medical management is
done in patients with stable vital parameters and minimal or no bleeding.
Medical management includes local or systemic injection of Methotrexate. The
medical management requires long duration follow up. Complications in medical
management like bleeding, failure of resorption or persistence of ectopic
pregnancy, morbid adherence of placenta in future pregnancy may later require
surgical management.[4] Also there is a possibility of long term
complications like scar dehiscence, scar rupture, and repeat cesarean scar
ectopic pregnancy. The surgical repair of the scar is recommended before the
next conception following Methotrexate treatment.[1] The success of
Methotrexate depends on serum βhCG level, size of ectopic pregnancy and cardiac
activity. High success rate is found if serum βhCG level is less than 3000
IU/L. Patient’s with serum βhCG levels more than 3000 IU/L can have good
outcome, but require long follow up, repeat doses of Methotrexate and higher
medical cost.[1,5] The presence of fetal cardiac activity on USG has
poor success with medical management.[5] The local injection of
Methotrexate into the gestational sac is a satisfactory form of treatment of
cesarean scar pregnancy.[4]
The follow up of medical management is done by serum βhCG which is
marker of trophoblastic viability. Other parameters used for monitoring are
gestational sac volume and degree of vascularity.[6] In our case, as the patient was having stable
vital parameters with minimal bleeding,
medical treatment with Methotrexate was given. The 15% drop between two
βhCG levels at an interval of a week is
expected with Methotrexate treatment. In our case the serum βhCG rose by 425%.
As our patient did not develop any bleeding, 200 mg of Mifepristone was given
for further treatment. Mifepristone is an antiprogesterone drug used in medical
termination of pregnancy in the first
trimester. The anti-progesterone activity of Mifepristone helps to
destroy and detach the chorionic villi, thus making Methotrexate more
effective. With use of Mifepristone there was a 33% fall seen in serum βhCG
level within one week. The fall continued on further follow up. USG showed an
increase in the size of the gestation sac when quantitative βhCG level was 387
mIU/mL probably due to bleeding that occurred due to detachment of the
chorionic villi. A meta-analysis has
reported the more effective use of
combination therapy of Methotrexate and Mifipristone over Methotrexate
alone [7].
Conclusion
Combination
therapy of Methotrexate and Mifepristone is found to be effective with less
requirement of repeated dose of Methotrexate avoiding its side effects. Further
studies are required for evaluation of combination therapy of Methotrexate and
Mifepristone or Mifepristone alone in management of cesarean scar ectopic pregnancy.
References
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