A delayed spontaneous second-trimester tubo-abdominal pregnancy diagnosed and managed by laparotomy in a “self-identified” infertile woman, a case report and literature review

Pathogenesis of APs is still controversial. Primary and secondary ones are classified. Pathogenesis mostly identified intraoperatively, confirmed pathologically. Primary peritoneal implantation is rare, and Studdiford proposed criteria for its diagnosis include the following:(1) normal tubes and ovaries, (2) absence of uteroplacental fistula, and (3) sufficiently early diagnosis to exclude the possibility of secondary implantation. The majority of cases are usually secondary implantation. Using the site of placental implantation as the key to distinguish pathogenesis of the secondary APs, Clark JF revealed that APs secondary to tubal abortion, tubal rupture and rupture or perforation of the uterus [18]. Most of advanced APs are usually secondary resulting from aborted or ruptured tubal pregnancy [19].

The definition of an AP is still obscure and controversial. AP has historically been defined as an ectopic pregnancy implanting in the peritoneal cavity [4]. It is obscure and less effective in secondary APs, especially late ones beyond the first-trimester. The definition of a late APs has been debated over the association between the placenta and the primary implant site [20, 21]. In 2008, Kevin C. Worley, MD etc. proposed that in advanced extrauterine pregnancy, irrespective sites of placenta, a more clinically useful definition of abdominal pregnancy is an extrauterine pregnancy in which all or most of the fetus develops within the abdominal [21]. But Mahajan NN argued that implantation of the placenta in the peritoneal cavity by Atrash et al. is a more logical and practical definition [20].

According the sites of placenta insertion in our case it can be classified as tubo-abdominal pregnancy, an uncommon form of APs secondary to ruptured tubal pregnancy. At the time of operation in this case, a particular phase of pathogenesis of secondary AP developed, secondary implantation of partial placenta on momentum occurred synchronously partial placenta remained in the primary implanted tube, with a living fetus abdominal growth. Removal of both implantation sites had been done, and the histopathology identified the insertion of villi in both the oviduct and the omentum specimens. Tubo-abdominal pregnancy, which was coined ever in 1910 by McCann F [22], reported by Clark JF in 1966 [18] and by E Holzer in 1976 [23], but rarely mentioned in current cases of APs, it may be explained by the rarity itself and the changes of occurrence of EPs. The delayed presentation allowed for the dynamic pathogenesis of the secondary AP, or the unique form of secondary APs to be clarified once again, tubo-abdominal pregnancy was firstly explicitly classified as secondary APs by Clark JF in his table. This case serves as a timely reminder to clinicians that patients’education is crucial to make early diagnosis.

The clinical symptom of abdominal pregnancy is variable and nonspecific, depending on the degree of the anatomical distortion it creates and the placental insertion site. But the following signs should bring the practitioner to think about the diagnosis: abdominal pain, bloody vaginal discharge, gastrointestinal symptoms, altered bowel movements, even painful fetal movements in APs [6, 24]. Risk factors for APs are low socioeconomic status, pelvic inflammatory disease, history of infertility, intrauterine device, endometriosis and assisted reproductive techniques. IVF is a known risk of APs in several trends including tubal factor infertility, history of tubal ectopic and tubal surgery, higher number of embryos transferred, and fresh embryo transfers and so on, many strategies are employed to reduce the incidence of APs in fertility treatment [25‐27].

In our case, she conceived naturally this time with her boyfriend. Except for infertility as the risk factor, previous IVF history should not be neglected. Puncture of ovarian in previous IVF procedure maybe to some extent account for the inflammation confirmed on both ovaries intraoperatively. The most importantly, women with IVF history may be high risk population to experience intended pregnancies. Fixed belief in infertility throughout her previous IVF treatment was a major barrier to contraception use resulting in an unexpected pregnancy [28], which raised many issues. The lack of information on the probability of spontaneous pregnancies (intrauterine or extrauterine ones) during and after the IVF procedure [28, 29], so she was unlikely to engage with counselling in department of Obstetrics and gynecology when symptoms existed. A missed and delayed AP still occurred in modern medicine. The views expressed by the women in our report is widely held by most infertile couples having IVF history. Our case sampled that fertility providers, could and should do more on educational interventions, healthcare professionals must all be armed with knowledge specific to women having had IVF history.

Moreover, eutopic or ectopic pregnancy is a competition between signals derived from the endometrium and the fallopian tube for blastocyst implantation, it is a complicated hormonally regulated process [30, 31]. As a steroid hormone discorded disease, PCOS was associated with an increased risk of EP after controlled ovarian hyperstimulation in fresh embryo transplantation cycles [32], it may be an unknown risk factor need to be focused on in spontaneous EP research in future. RIF history in this PCOS woman who got abdominal pregnancy, partially indicate endometrial receptivity maybe a reason need pay attention to [33]. At last, in intra-uterine insemination cycles, EP is associated with sperm source [34], although she got APs with her new partner, but little evidence is available to answer the male factor involved in the etiology of this spontaneous AP.

Ultrasonography is available, non-invasive method which can allow to distinguish the APs. The sonographic criteria proposed by Gerli et al.in 2004 can be followed in the first-trimester to make a diagnosis of APs [35]. The APs diagnosed in early gestation is usually confirmed as primary ones by laparoscopy and managed successfully. In the second trimester, APs can be diagnosed using the following criteria proposed by Allibone et al. in 1982:Empty uterine cavity; No evidence of a dilated Fallopian tube or complex adnexal mass; Gestation sac surrounded by loops of bowel and separated by peritoneum; Wide mobility similar to fluctuation of the sac [36]. But the most frequent and reliable finding was separation of the uterus from the fetus (90%) and extrauterine placenta (75%) [37]. In the late individual cases, especially when a rupture occurs, they still present a diagnostic dilemma. In our case, a second-trimester AP was diagnosed preoperatively, but accurate detection of site of placental implantation and relationship with surrounding tissue was challenging in an emergent situation by sonography. Magnetic resonance imaging (MRI) which is better for clarifying anatomic relationship with surrounding structures, vascular supply, placental site, and unusual fetal lie [38], but it is not available in our patient who presented with shock requiring immediate surgical intervention for life saving. A laparotomy approach was chosen individually. As revealed intraoperatively, the rupture occurred at primary implanted site rather than secondary implanted site, the placenta partially inserted into the omentum, notably, it was the early stage of pathogenesis of secondary APs and the lack of broadly and deeply trophoblastic invasion into other important organs alleviated the difficulty of placental dissection and removal of the conception products.

It was unique to report an unexpected spontaneously APs in PCOS woman with a previous IVF history. “Self-identified” infertility led to a missed and delayed second-trimester APs, it was a case need laparotomy in emergency, with a loss of opportunity for medical treatment, and severe damage to the woman’s subsequent reproductive potential. Diagnosis and management modalities in EPs and APs should be a multidisciplinary systematic team work that includes high-risk population identification, provision of pregnancy and contraception knowledge, early diagnosis, appropriate management and available strategies for re-pregnancy and re-contraception after EPs and APs. A tubo-abdominal pregnancy mentioned again, serving as a timely reminder to clinicians, with the widely availability of artificial reproductive technology in maternal and child health care, focusing on educational interventions in women having previous IVF history is primitive prevention of EPs and APs, with an important socioeconomic value.