Idiopathic spontaneous haemoperitoneum at 4 weeks gestation

A 20-year-old nulliparous patient with acute-onset abdominal pain and imaging suggestive of haemoperitoneum was admitted for observation. Though, initially, haemodynamically stable, her clinical picture worsened throughout her hospitalisation and warranted two separate laparoscopies that revealed 1200 mL and 50 mL of haemoperitoneum, respectively, without an identifiable bleeding source. After serial β-human chorionic gonadotropin levels and ultrasound confirmation of a viable pregnancy 23 days later, the patient underwent a normal antenatal course and delivered a healthy infant at 37 weeks gestation. This unusual case highlights the need to consider spontaneous haemoperitoneum in pregnancy as a diagnosis, particularly in the setting of pregnancy of unknown location, even at an early stage of pregnancy.

pregnancy, reproductive medicine, ultrasonography, sexual health, obstetrics and gynaecology

Spontaneous haemoperitoneum is defined as intra-abdominal haemorrhage from a non-traumatic cause and can be detrimental.1 Several case reports have described spontaneous haemoperitoneum in pregnancy (SHiP) as a rare cause of haemoperitoneum in the third trimester, most often associated with ruptured utero-ovarian vessels.2 We describe a 20-year-old nulliparous woman who presented to our institution with worsening acute abdominal pain. Her symptoms were ultimately attributed to spontaneous intraperitoneal haemorrhage without an identifiable bleeding source. Additionally, this haemorrhage was in the setting of a pregnancy of unknown location (PUL) at 4 weeks gestation. Her pregnancy was subsequently identified as a normal intrauterine pregnancy and carried to term. Case presentation A 20-year-old nulliparous white woman presented to an academic medical centre with acute onset abdominal pain, right shoulder pain, nausea, and vomiting. The patient was normotensive, tachycardic to the 120s and had an initial haemoglobin of 12.4 g/dL (haematocrit (Hct): 35.5%, platelets: 368 x 109/L). A urine pregnancy test was positive and serum quantitative β human chorionic gonadotropin (hCG) was 136 mIU/mL. Her physical examination was notable for mild abdominal tenderness to palpation. A transvaginal ultrasound revealed complex free fluid in the posterior cul-de-sac without adnexal masses, normal appearing ovaries, and no visible intrauterine or extrauterine gestational sac (figure 1). The patient was admitted for observation and serial abdominal examinations given her initial haemodynamic stability. After 2 hours, the patient endorsed worsening abdominal tenderness and exhibited positive peritoneal signs. Her tachycardia increased to the 140s, and haemoglobin declined to 10.2 g/dL (Hct: 29.2%, platelets: 306 x 109/L). Due to this acute change, the patient was consented for laparoscopy with possible removal of suspected ectopic pregnancy. Intraoperatively, approximately 1200 mL of haemoperitoneum was evacuated without an identifiable bleeding source or clear findings of an ectopic pregnancy (figure 2). Several brown pigmented areas, suggestive of endometriotic implants, were seen in the cul-de-sac, and the peritoneal surface appeared to be scarred (figure 3). Given no clear evidence of ectopic pregnancy, salpingectomy or salpingostomy was not performed. The patient remained in the hospital for observation and serial quantitative β-hCG levels. During her observation period, the patient again noted increasing abdominal and shoulder pain. Laboratory values were significant for a downtrending haemoglobin level; CT scan findings showed a layered haemorrhage within the pelvis as well as uterine cavity distension. Concern for ongoing intraperitoneal bleeding prompted re-exploration on postoperative day 2. During the second laparoscopy, 50 mL of haemoperitoneum was evacuated. The left fallopian tube appeared oedematous, hyperemic and easily friable—all signs concerning for a partially expelled ectopic pregnancy. A left salpingectomy was performed and sent to surgical pathology, but no ectopic pregnancy was identified on histopathology. Outcome and follow-up After her second operative intervention, the patient’s quantitative β-hCG levels continued to rise (figure 4) until an intrauterine pregnancy was visualised on ultrasound 23 days after the second laparoscopy. Her antenatal course was significant only for gestational hypertension, which was diagnosed at 36 weeks gestation. The patient underwent induction of labour at 37 weeks gestation and delivered a viable female infant. The postpartum course was uncomplicated, and both the patient and her daughter were doing well at her 6-week postpartum visit.

SHiP is intraperitoneal bleeding in pregnancy without any traumatic cause. SHiP has most commonly been described in the second half of pregnancy, during labour, or in the early postpartum period.2 Non-traumatic intraperitoneal bleeding that occurs up to 42 days after delivery meets the criteria for SHiP.2 Theories on SHiP aetiology The most common theories regarding the aetiology of SHiP involve endometriosis, vessel rupture or haemorrhagic cyst rupture.2 Associations with assisted reproductive technologies (ARTs) have also been identified.3 Vessel rupture usually occurs due to anatomically abnormal aneurysmal vessels or anatomically normal vessels under increased stress from thromboses or adjacent pathology.1 If large enough, blood vessel penetration of physiologic corpus luteal cysts can lead to haemorrhage or haemoperitoneum.2 One review found that women who underwent controlled ovarian hyperstimulation followed by embryo transfer had higher incidences of SHiP than those who did not require ART.3 However, it should be noted that a majority of these patients were diagnosed with endometriosis (22/24 patients) prior to undergoing ART; these findings suggest that ART may have a synergistic effect with endometriosis that increases the likelihood and severity of SHiP.3 Endometriosis is the most well-researched aetiology of SHiP. A non-human primate model showed that baboons with endometriosis experienced blood-stained peritoneal fluid during menses compared with baboons without endometriosis.4 Similarly, existing literature shows a well-documented association between endometriosis and SHiP in humans.5 One study concluded that the predisposition of endometriotic lesions for the left lateral hemipelvis and the high number of SHiP bleeding sites identified in the left lateral hemipelvis were associated.6 Endometriosis is believed to contribute to SHiP by several mechanisms. First, the chronic inflammatory state associated with endometriosis results in friable utero-ovarian vessels that are more likely to bleed spontaneously or with minimal trauma.6 Pregnancy also contributes to an increased bleeding risk due to rapid decidualisation and enlargement of endometriotic implants during the first trimester.5 Later in pregnancy, these endometriotic lesions shrink, leading to decidual necrosis and involution.7 Clinical presentation of SHiP The typical presentation of SHiP involves a second or third trimester patient, with mean occurrence at a gestational age of 28 weeks in 89.7% of cases.5 SHiP patients often present with acute abdominal pain followed by subsequent development of hypovolaemic shock and fetal distress.6 While exact incidences are unknown, a 2017 systematic review characterised around 60 cases of SHiP in the existing literature.6 The maternal mortality rate and perinatal mortality rate of ShiP is estimated to be 1.7% (1/59 cases) and 26.9% (18/67 fetuses), respectively.6 Though SHiP may present similarly to ectopic pregnancy, estimated gestational age remains the primary differentiating factor. Ectopic pregnancy generally presents in the first trimester with abdominal pain, vaginal bleeding and peritoneal findings.8 The estimated incidence of ectopic pregnancy is up to 2.6% of all pregnancies with a 6% maternal mortality rate in early pregnancy.8 Current algorithms analysis In examining this case retrospectively, we reviewed current management algorithms for tubal ectopic pregnancy and PUL. The American College of Obstetricians and Gynaecologists (ACOG) recommends transvaginal ultrasound with confirmation of pregnancy as the minimum evaluation for suspected ectopic pregnancy.9 For patients without ultrasound confirmation of pregnancy, quantitative serum β-hCG levels can be serially trended to evaluate for levels within the ‘discriminatory zone’ and/or evidence of a non-viable pregnancy.9 Most relevant to our case is the consensus that patients who display ‘haemodynamic instability or an acute abdomen should be evaluated and treated urgently’.9 For patients with PUL, ACOG urges clinicians to establish a definitive diagnosis through continued evaluation.9 A new algorithm published in November 2020 prioritises maternal choice regarding pregnancy disposition in PUL.10 The algorithm assesses pregnancy desire and utilises a shared decision-making model to proceed with conservative management or expedite active management.10 Other researchers reviewed the management of PUL, but focused solely on non-viable pregnancies that were treated with uterine curettage or methotrexate.11 Most recently, the randomised control trial ‘ACT-or-NOT’ is evaluating optimal management of women with PUL; this study requires those enrolled to be haemodynamically stable in order to be eligible.12 Thus, all current evidence-based guidelines for evaluating a patient similar to the one presented in this case report will not adequately consider SHiP in the differential diagnosis. Case analysis Our case is unique for several reasons. First, current evaluation algorithms overlook patients like ours and do not consider SHiP as an aetiology for abdominal pain in early pregnancy. Based on the algorithms described in this analysis, a patient with acute abdominal pain, haemodynamic instability and a positive pregnancy test will always be taken to the operating room with concern for suspected ectopic pregnancy. Despite its rarity, SHiP should be part of the general obstetrician’s differential diagnosis and remain a condition, which general obstetricians are comfortable managing. Since untreated SHiP leads to high rates of maternal and fetal fatality and improperly managed SHiP leads to unnecessary surgical interventions that may have implications for future fertility, SHiP must be considered throughout pregnancy. Second, this case highlights the unique use of laparoscopy in the evaluation of SHiP. Of the 59 cases of SHiP reported in iterature review by Lier et al, 56 required surgical intervention: 53 were evaluated via laparotomy and only three were successfully managed through laparoscopy.6 The three successful laparoscopic interventions occurred in women diagnosed with SHiP at 15 weeks gestational age, 2 days postpartum and 7 days postpartum.6 This case, therefore, adds to the small pool of SHiP cases evaluated with laparoscopy. This case also highlights the use of minimally invasive surgical techniques for evaluating SHiP in early pregnancy or the postpartum period. Finally, to our knowledge, this is the earliest documented case of ShiP having occurred at only 4 weeks gestation. This is also the earliest case resulting in a viable pregnancy. Lier et al reported an average gestational age of 28 weeks for endometriosis associated SHiP and 32 weeks for SHiP without endometriosis.6 The earliest published case of SHiP resulting in a viable pregnancy occurred at 15 weeks gestation, confirming that our case challenges the assumption of SHiP occurring primarily in the second and third trimesters.6 Though SHiP is rare, it is important for practitioners to consider in their differential diagnosis of haemoperitoneum in pregnancy. This is particularly true in the evaluation of patients whose pregnancy location has not yet been confirmed. Learning points. Detail the various aetiologies of spontaneous haemoperitoneum in pregnancy (SHiP). Assess the current evaluation algorithms used to diagnose patients who present with symptoms of SHiP. Highlight the rationale for including SHiP in the differential diagnosis of acute abdominal pain in a patient with pregnancy of unknown location. Footnotes Twitter: @emily_obs Contributors: All authors have made substantial contributions to the work as listed below. RF contributed to the conception of the work, the analysis of data, drafting and critically revising the work, offering final approval of the version published and agreeing to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. EO’B offered substantial contributions to the design of the work, the analysis and interpretation of data, drafting and critically revising the work for important intellectual content, offering final approval of the version published and agreeing to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. SJ contributed to the conception of the work, the analysis of data, drafting and critically revising the work, offering final approval of the version published and agreeing to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. Competing interests: None declared. Provenance and peer review: Not commissioned; externally peer-reviewed. Ethics statements Patient consent for publication Obtained.

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