Fall, 2013

Patient History and Signs and Symptoms
A 34-year-old white female, G3P1011, presented to the ED 4 days ago with vaginal bleeding. Ultrasound revealed a pregnancy “within the lower uterine segment or cervical canal”. She has been directed to a Maternal-Fetal Medicine Center for consultation and treatment options. Four days later the patient’s bleeding slowed. She denied abdominal pain. The patient had a cesarean delivery with her first child.

Sonographic Appearance and Imaging Tips
Transvaginal and transabdominal ultrasound exams were performed. The endometrial cavity was empty. A single gestational sac containing a small fetal pole with cardiac activity (167 bpm) are noted inferior to the uterine cavity. On transvaginal imaging, the gestational sac (2.1 x 2.3 cm) has a normal rounded contour and appears to be located anterior and to the maternal right of the cervical canal, just inferior to the cesarean niche. Gestational age was 8 weeks, CRL measured 16 mm. Below are the images of the patient’s cervix in sagittal plane with visualization of the gestational sac containing a fetal pole (image on the left) and yolk sac (image on the right). Free fluid is seen anterior to the cervical region.

Cesarean scar pregnancy is best visualized with transvaginal scanning as it provides the most detailed image and the closest distance to the area of interest. Cervix is scanned in coronal and sagittal planes. M-mode is used for detection of the cardiac activity. Criteria used for diagnosis of cesarean scar pregnancy are an empty uterus, empty cervical canal, development of the sac in the anterior part of the lower uterine segment, and an absence of healthy myometrium between the bladder wall and the gestational sac. (1, p. 1038)

Other Diagnostic Methods/Criteria
Diagnostic laparoscopy is considered the gold standard for diagnosis of ectopic pregnancy. The combined use of serum hCG testing and transvaginal sonography is the current noninvasive approach. (1, p. 1024)

In our case, at the time of presenting patient’s beta hCG measured 73,628.

Treatment Options
It is not impossible for the pregnancy to progress to viability, but not without substantial risk to maternal health. The patient was not interested in expectant management and desired future fertility avoiding hysterectomy. A wide variability in therapeutic approaches was described in the literature. The presence of fetal cardiac activity necessitated aggressive therapy. Local and systematic injections of methotrexate have been described with success. Methotrexate stops the growth of rapidly dividing cells, such as embryonic, fetal, and early placenta cells. This medication can be given as a single shot or as several injections. If an ectopic pregnancy continues after 2 or 3 doses of methotrexate, surgical treatment is needed to remove the ectopic pregnancy. Although it is an uncommon practice, methotrexate can be given every other day until pregnancy hormone (hCG) blood tests confirm that the pregnancy has ended. Severe side effects from methotrexate are most likely to develop with long-term use, such as when it is used for cancer treatment. (2)

The patient has been treated for 4 months. Ultrasound examinations were ordered to follow-up any changes. The patient’s beta hCG levels has been dropping:
  • 73,628 IU at the day of presenting;
  • 36,483 IU 9 days later;
  • 1898 IU 3 weeks after presenting;
  • 205 IU 5 weeks after presenting;
  • 7 IU 2 months after presenting.
The patient was bleeding throughout entire treatment period.

A month after treatment the gestational sac had mixed echogenicity with a small amorphous smooth fetal pole. There was no blood flow in the placental tissue.

Four months after initial presentation at the MFM, significant improvement in images was noted. The scar defect measured 8 mm. The gestational sac was 1.7 x 1.3 cm in size and had a homogeneous hypoechoic appearance consistent with a resolving pregnancy or old blood. The uterine cavity appeared normal with some fluid. Patient had not had any bleeding for one week.

The immediate complications of Cesarean scar pregnancy are uterine rupture, severe bleeding, need for hysterectomy, and maternal morbidity. Long-term outcomes to be considered after conservative treatment are future fertility and recurrence of Cesarean scar pregnancy. Success with methotrexate was five of seven patients (71%), with the two failures requiring emergent surgery. (3) A recent study of 29 successfully treated women with follow-up data reported favorable reproductive outcomes and an apparently low recurrence rate. Out of the 24 women attempting to become pregnant, 21 conceived spontaneously (20 intrauterine pregnancies and one recurrent scar pregnancy). Thirteen of the 20 intrauterine pregnancies appeared normal; 9 were delivered by Cesarean section. The other 7 pregnancies ended in spontaneous abortions. (4)