Keywords
ectopic pregnancy - heterotopic pregnancy - triplet gestation - cesarean scar - uterine
ablation - abortion
Background
Spontaneous triplet pregnancies occur at a rate of approximately 1 in 4,000 pregnancies.
Heterotopic pregnancies, defined as the presence of multiple gestations with one (or
more) being present in the uterine cavity and the other(s) outside the uterus, occur
at a rate of approximately 1 in 30,000 pregnancies. Heterotopic triplet pregnancies
have been reported in case reports.[1]
[2]
[3]
[4]
[5]
[6] Cesarean scar ectopic is a rare event with no currently reported rates, but this
condition is becoming more common as women undergo more cesarean sections.[7] Those who continue cesarean scar pregnancies are at high risk of morbidity such
as placenta accreta spectrum (PAS), cesarean scar dehiscence/uterine rupture, postpartum
hemorrhage, and postpartum hysterectomy.[7]
Pregnancy after uterine ablation is a rare complication with incidence estimated at
approximately 1 to 3%. A limited number of women elect to continue pregnancy after
ablation, but those who do experience high rates of PAS, preterm delivery, malpresentation,
and all-cause perinatal mortality.[8]
Ours is the only reported case, per the authors' extensive review of the literature,
of spontaneous heterotopic triplet pregnancy involving one cesarean scar pregnancy
following uterine ablation. This confluence of conditions is unique, and each condition
alone carries high risk to the pregnant patient. This case highlights the difficulty
in counseling a patient with multiple such conditions and the importance in maintaining
the ability to offer termination in cases of proven high-risk morbidity, even if the
patient is clinically stable at diagnosis. The learning objectives from this case
apply to patients with any combination of the multiple conditions that are concurrently
exemplified in this one patient.
Case Presentation
This is a case of a woman in her 30s, gravida 6, para 4014, who initially presented
with pelvic pain and vaginal bleeding at an outside facility. She had a positive pregnancy
test and transvaginal ultrasound showed a heterotopic pregnancy with two intrauterine
pregnancies and one pregnancy at the lower anterior uterus, at the prior cesarean
scar. The patient had a medical history of chronic iron deficiency and possible von
Willebrand's disease without a certain diagnosis. She had previously low levels of
von Willebrand factor activity and a history of heavy menstrual bleeding as well as
postpartum hemorrhage requiring blood transfusion. Prior hematologic workup records
were not available. Her surgical history was significant for four prior cesarean sections
at term as well as uterine ablation that was performed for heavy menstrual bleeding.
At the time of presentation to our facility, the patient had a known heterotopic cesarean
scar pregnancy and had been discharged from several other facilities without any certain
treatment plan due to the complexity and rarity of her case and uncertainty regarding
management. On presentation to our facility, she was experiencing light vaginal bleeding.
She did not have significant pelvic pain and her vital signs and examination were
stable.
Investigations
Transvaginal ultrasound on initial presentation showed an intrauterine tri-chorionic,
tri-amniotic triplet gestation. Fetus A was within a low-lying gestational sac near
the lower uterine segment near the cesarean section scar and had a crown rump length
of 3.1 mm, measuring 5 weeks and 6 days with no fetal cardiac activity. Fetus B had
a crown rump length of 8.9 mm, measuring 6 weeks and 6 days with normal fetal cardiac
activity, and was noted to be immediately adjacent to the prior cesarean scar and
adjacent to the gestational sac of fetus A ([Fig. 1]). Fetus C had a crown rump length of 11.3 mm, measuring 7 weeks and 2 days with
normal fetal cardiac activity, and was located at the right uterine fundus. There
was a small subchorionic hemorrhage noted adjacent to fetus C. The patient was discharged
in stable condition with a plan for close follow up with Maternal Fetal Medicine to
discuss further management. The patient presented again the following day with continued
vaginal bleeding. Her vital signs remained stable and vaginal bleeding was overall
minimal. Repeat transvaginal ultrasound no longer appreciated fetus A. Fetus B was
again seen with normal cardiac activity in an abnormal position in the lower uterine
segment adjacent to the uterine scar with very thin myometrium measuring 0.097 cm
with a distorted gestational sac with bulbous superior anterior component ([Figs. 2] and [3]), highly concerning for cesarean scar ectopic. Fetus C was again seen at the fundus
with normal cardiac activity.
Fig. 1 Transvaginal ultrasound (TVUS) on hospital day 1. (A) A transverse view of the lower uterine segment with fetus A on the right and fetus
B on the left, adjacent to each other and both abutting the cesarean section scar.
(B) A longitudinal view of the uterus with fetus B in the lower anterior uterine segment
and fetus C at the fundus. (C) Gestational sac for fetus B with irregular shape and immediately adjacent to the
cesarean scar.
Fig. 2 Transvaginal ultrasound (TVUS) on hospital day 2, demonstrating fetus C and fetus
B, with irregular gestational sac for fetus B demonstrating bulbous superior anterior
component.
Fig. 3 Transvaginal ultrasound (TVUS) on hospital day 2, demonstrating thin myometrium (0.097 cm)
anterior to the gestational sac of fetus B.
Due to the patient's history of uterine ablation, the cesarean scar pregnancy of fetus
B, triplet gestation, and missed abortion of fetus A, she was counseled on the high
morbidity associated with continuing this pregnancy and was offered termination of
pregnancy. This was an undesired pregnancy, and the patient understood the risks to
her own health associated with continuing the pregnancy as well as the very low likelihood
of the pregnancy resulting in a live birth. Thus, the patient elected for termination
of pregnancy. In accordance with institutional policy, the Ethics Committee met to
discuss the case and approved the termination. Hematology was consulted due to the
patient's history of low von Willebrand factor activity and she was found to have
normal von Willebrand factor activity and antigen. It was thought that her previously
low levels of von Willebrand factor activity could be due to her O blood type. Clotting
factors were also checked and were normal. She was cleared for surgery by hematology.
Treatment
The patient underwent suction dilation and curettage with concurrent laparoscopic
bilateral salpingectomy without complications. Intraoperatively, a survey of the patient's
pelvis and abdomen revealed normal anatomy with excess scaring of the uterus anteriorly
with the bladder. Her total blood loss from both procedures was 400 mL and she recovered
well and was discharged home in stable condition the day of surgery.
Outcome and Follow-Up
The patient was seen for follow-up 2 weeks postoperatively, at which time she reported
feeling well and had no complications. The patient was incredibly thankful for the
care she received, stating that at outside institutions she was discharged home without
any plan for treatment or follow-up and was told to present again when she started
spontaneously miscarrying. The patient perceived that other institutions' medical
teams were uncomfortable managing her multiple rare conditions compounded with physicians'
discomfort with termination of the remaining two live pregnancies.
Discussion
This case highlights several high-risk pregnancy conditions and their potential implications.
Pregnancies following uterine ablation, cesarean scar pregnancy, and heterotopic triplet
pregnancy are all rare events. The co-occurrence of these conditions in our patient
is an extremely rare event that, to the best of our knowledge, has not been previously
reported in the literature. Given the rarity of the patient's conditions and the two
live intrauterine pregnancies, the patient felt that the initial providers who treated
her were uncertain as to the proper course of treatment. A thorough review of the
literature describing cases involving each of her separate conditions is helpful in
guiding counseling the patient and in determining the treatment approach. Because
our patient did not desire to continue the pregnancy, she was offered termination
via dilation and curettage but was also counseled on possible need for hysterectomy
in the event of uncontrollable bleeding at the cesarean section scar. The patient
had no surgical complications.
Pregnancy after uterine ablation is a fairly rare event, experienced in about 1 to
3% of people who have undergone this procedure.[8] Most patients with a pregnancy following uterine ablation do not choose to continue
the pregnancy; these pregnancies are more likely to result in PAS, preterm delivery,
and malpresentation. A 7-year retrospective review of 7,863 women who underwent endometrial
ablation (by thermal balloon, microwave, cryoablation, or radiofrequency ablation)
published by Fernandez et al in 2021 found a post-ablation pregnancy rate of 1.5%
at 18 months.[9] Another study by Ibiebele et al in 2020 followed 18,559 women with an endometrial
ablation and found a post-ablation pregnancy rate of 3.1%. Among this population,
there were high rates of cesarean delivery (43%), preterm birth (13%), twin or higher-order
pregnancies (n = 54, 9%), and stillbirth (13.3/1,000 births).[10]
Cesarean scar ectopic is a rare event as well; there are no reported rates, but this
condition is becoming more common as women undergo more cesarean sections. Prompt
and accurate diagnosis of cesarean scar pregnancy is difficult as presentation is
variable—possibly with pelvic pain and bleeding but patients can also be asymptomatic.
Treatment for cesarean scar ectopic pregnancies is not standardized, but the Society
for Maternal Fetal Medicine recommends surgical management with possible intra-gestational
methotrexate. Those who choose expectant management and continue cesarean scar pregnancies
are at high risk of morbidity such as PAS, cesarean scar dehiscence, uterine rupture,
postpartum hemorrhage, and postpartum hysterectomy.[7]
Heterotopic pregnancy is estimated to occur in approximately 1 in 30,000 pregnancies.
Spontaneous heterotopic triplet pregnancies are very rare, with only three cases reported
in the literature. One case from 1903 reported by Marshal et al resulted in uterine
rupture and death of all three fetuses as well as the mother.[2] Another was a case reported by Guimarães et al in 2019. It was a case of spontaneous
pregnancy in a nulliparous patient with a known intrauterine twin gestation presenting
with right lower quadrant pain and presumed to have appendicitis. She underwent exploratory
laparotomy and was found to have a normal appendix and a ruptured right tubal ectopic
pregnancy.[2] Another case published by Nkurunziza et al in 2019 reported a case in Rwanda of
a patient who had an intrauterine device (IUD) in place when she became pregnant.
She presented in hemorrhagic shock and had to be transferred to a trauma center and
had an exploratory laparotomy, which revealed an abdominal pregnancy as well as two
intrauterine pregnancies with cornual uterine rupture and demise of all three triplets
at 18 weeks. The patient underwent gravid hysterectomy and evacuation of 4 L of hemoperitoneum
and survived.[6]
Heterotopic pregnancy most commonly refers to one tubal pregnancy and one intrauterine
pregnancy. However, heterotopic cesarean scar pregnancies have been reported mostly
in the context of in vitro fertilization (IVF) with embryo transfer. Ouyang et al
reviewed 20 cases of cesarean scar heterotopic pregnancies, all resulting from IVF
embryo transfer managed with a variety of approaches (including surgical treatment,
ultrasound-guided potassium chloride injection, and expectant management) with just
1 of the 20 pregnancies resulting in a live birth of a cesarean scar pregnancy.[11] Another study reviewed 23 cases of heterotopic cesarean scar pregnancy with multiple
approaches to management (including laparoscopic excision, hysteroscopic incision,
open excision, ultrasound-guided potassium chloride injection, and expectant management).
Of these 23 cases, there were 4 cases of scar rupture, 6 cases of Placenta Accreta
spectrum, 10 cases of postpartum hemorrhage, and 3 cases of peripartum hysterectomy.
There were 2 first trimester losses, 2 second trimester deliveries, 11 preterm deliveries,
and 8 term deliveries.[5]
Authreya et al reviewed the literature and found 23 heterotopic triplet pregnancies.
The majority of these were a result of IVF embryo transfer and resulted in concurrent
tubal and intrauterine pregnancies.[5] Our literature review revealed two cases of cesarean scar heterotopic triplet pregnancy.
Both cases were the result of IVF transfer of three viable embryos. One case reported
by Hsieh et al in 2004 resulted in one cesarean scar pregnancy and two normal intrauterine
pregnancies. This patient underwent vacuum aspiration of the contents of the gestational
sac at the cesarean scar and subsequently carried the remaining two intrauterine pregnancies
to 32 weeks, at which time the patient underwent an emergent cesarean delivery for
preterm labor.[12] In 2011, Litwicka et al reported another case with two cesarean scar pregnancies
and one normal intrauterine pregnancy, which was managed with intra-gestational potassium
chloride and methotrexate followed by aspiration of the contents of the two cesarean
scar gestational sacs. That patient went on to deliver a single live fetus at 36 weeks.
Delivery was complicated by placental abruption and the fetus was found to have missing
digits and malformed ears, which was initially thought to be a deformity related to
possible methotrexate exposure but was later found to be an unrelated genetic mutation,
Miller syndrome.[4]
This case is unique in that our patient was at risk of complications of cesarean scar
pregnancy as well as risks associated with triplet pregnancy and pregnancy after uterine
ablation. Occurring alone, each of these conditions increases the risk of spontaneous
abortion, intrauterine fetal demise, preterm labor, and postpartum hemorrhage. Additional
risks for the patient being discussed included dehiscence of the uterine scar, PAS,
uterine rupture, and a significant risk of peripartum hysterectomy. The patient was
amenable to dilation and curettage; because of these confounding risks, the patient
was also offered hysterectomy, which she declined unless as a lifesaving measure.
If the patient had chosen to continue this pregnancy, her management could be guided
by prior reports of management of heterotopic cesarean scar pregnancy with methods
such as potassium chloride injection and/or aspiration of the cesarean scar pregnancy.
However, she still had significant risk associated with pregnancy after uterine ablation,
which has not been reported before in the context of her other comorbid obstetric
conditions. This case demonstrates the use of prior reported cases to guide counseling
and management of a rare constellation of conditions. The patient was able to make
an informed decision regarding her treatment because of the counseling provided using
information from prior cases and was satisfied with her care. This case also highlights
multiple conditions that warrant a discussion of treatment options including termination
of pregnancy. This patient presented in a clinically stable condition. It is imperative
to note, however, that she was referred to our care after seeking care with different
health care providers, who (according to the patient) were uncomfortable managing
her care. Had the patient continued the pregnancy, she could have developed acute
instability with any of the possible complications listed earlier and could have required
emergency termination of the pregnancy, among other interventions, to save her life.
Given this risk, her ability to terminate the pregnancy before these complications
occurred serves as an example of the need for easily accessible, safe termination
of pregnancy for all patients who may desire or need a termination of pregnancy. It
further highlights the need to seek prompt treatment and the importance of appropriate
counseling to ensure that the patient understands the importance of timely treatment
and follow-up.
