We retrospectively analyzed all the inpatients in the department of obstetrics and gynecology from Nanjing Drum Tower Hospital between July 2010 and December 2015. A total of 17 patients with diagnosed heterotopic interstitial pregnancy were included in the present study, suggesting an overall incidence of 0.04% for all the deliveries (n = 40,761) at our institution over the same study period. The Reproductive medicine center of our hospital is the first batch approved by the Ministry of health to carry out ART, and therefore it serves for infertility patients throughout the country. Nearly 18,000 patients conceived by ART during the study period. The heterotopic interstitial pregnancy was diagnosed by experienced radiologist using 2-D ultrasound.
The criteria included an intrauterine pregnancy along with feature of a co-exisiting interstitial pregnancy, i.e. a gestational sac visualized high in the fundus, and not surrounded by 5 mm of myometrium in all planes; and a gestational sac seen separately and < 1 cm from the most lateral edge of the uterine cavity . Exclusion criteria referred to an ectopic gestational sac observed in another location such as fallopian tube, ovary, cervix, or abdominal cavity. This study was performed according to the Declaration of Helsinki and approved by the institutional review boards of Nanjing Drum Tower Hospital (NJDTH20160810).
Each patient’s age, gravidity and parity, history of pelvic inflammatory disease or surgery, gestational weeks at diagnosis, and clinical symptoms of abdominal pain and vaginal bleeding was retrospectively collected by reviewing the medical records. We also recorded whether the current pregnancy had been conceived naturally or by ART. The gestational age was calculated by adding 14 days to the date of embryo transfer. Routine transvaginal ultrasound examination was performed at approximately 6 weeks of gestation (i.e. 4 weeks after embryo transfer) in all the pregnant women, and a repeat ultrasound scan was performed after a two weeks interval, or promptly if the patient presented with clinical symptoms of abdominal pain or vaginal bleeding at any time.
The therapeutic intervention, including surgery (either laparoscopy (KARL STORZ ENDOSKOPE) or laparotomy with cornual resection, or hysterectomy), medical treatment, or expectant management, was collected from each patient. The operative time, volume of intra-operative haemorrhage, length of hospital stay and incidence of intra-operative and postoperative complications were recorded. A transvaginal ultrasound scan was performed on the third day postoperative or before discharge to confirm the fetal viability of intrauterine gestation in each patient who continued with their intrauterine pregnancy.
Medical treatment comprised aspiration of ectopic fetal heart along with products of conception and local injection of 10% potassium chloride (KCl) into cornual gestational sac under transvaginal ultrasound guidance (SIEMENS G50). In the patients under medical or expectant management, due to the possibility of miscarriage of intrauterine pregnancy and rupture of extrauterine pregnancy, repeated clinical and ultrasound examinations were performed weekly until a complete resolution of interstitial pregnancy was confirmed.
Furthermore, to investigate the pregnancy outcome, we invited each patient to a face-to-face interview conducted during August 2016 to January 2017. Of the 17 patients, 16 women gave their oral and written informed consent on behalf of themselves and their children during the face-to-face interview. Nevertheless, one case refused our face-to-face invitation over the telephone because she underwent a missed miscarriage at 8 gestational weeks following expectant management; but she provided the verbal informed consent for participation in the study and publication, and also agreed to sign the written informed consent if requested. The median child’s age was 3.5 years (range, 1–6 years) at our follow-up study. Data recorded for all the live births comprised of gestational age, mode of delivery, the infant’s birth weight, height and gender, which were collected from the child health record. This parent held record contained details of the child’s vaccinations, growth, and development, which was assessed by professional child health care doctor. During the face-to-face interview, based on the child health and development record, we evaluated the infant’s overall health condition including congenital malformations, intelligence, hearing, and language. Each infant’s height and weight was measured.
Statistical analysis was performed with the SPSS software (SPSS Standard version 17.0, SPSS Inc., Chicago, IL). Quantitative data non-normally distributed were presented as median (range) and compared by Wilcoxon rank sum test between two groups; categorical variables were reported as number (percentage). A two-sided P value< 0.05 is considered statistically significant.