Early Pre‐Rupture Diagnosis of Live Heterotopic Pregnancy Using Transvaginal Ultrasound, With Successful Laparoscopic Management and Preservation of the Intrauterine Pregnancy

ABSTRACT

Heterotopic pregnancy, though rare, should be suspected in early pregnancy with abdominal pain or bleeding, even when an intrauterine pregnancy is confirmed. Prompt transvaginal ultrasound and timely laparoscopic management are essential to prevent life‐threatening complications and preserve the intrauterine pregnancy.

1. Introduction

Heterotopic pregnancy (HP) is defined as the simultaneous presence of intrauterine and ectopic gestational sacs. HP occurs in approximately 1 in 15,000 to 1 in 30,000 spontaneously conceived pregnancies [1], with the risk increasing to 1%–3% in pregnancies resulting from assisted reproductive technologies (ART) [2]. The fallopian tube is the most common site of ectopic implantation in both spontaneous and ART‐associated HP, followed by the cornual region, while cervical, ovarian, and abdominal heterotopic pregnancies are extremely rare [3, 4]. The most significant risk factor for HP is ART. Additional risk factors include a history of ectopic pregnancy, tubal or pelvic pathology, prior pelvic surgery, pelvic inflammatory disease, endometriosis, multiparity, and smoking.

Clinical presentations of HP are often non‐specific, such as pelvic pain or vaginal bleeding, which overlap with other early pregnancy complications [5]. Identifying an intrauterine pregnancy (IUP) may give clinicians and sonographers a false sense of security. These diagnostic challenges increase the risk of delayed diagnosis, potentially resulting in tubal rupture, hypovolaemic shock, and maternal or fetal death [1].

Transvaginal sonography is the diagnostic gold standard for early detection of HP, identifying both intrauterine and ectopic gestational sacs in up to 84% of cases [5]. Thorough adnexal evaluation is essential, especially in patients with risk factors such as ART, previous ectopic pregnancy, pelvic inflammatory disease, or prior tubal surgery [6].

Laparoscopic management is the preferred, safe, and effective approach for the removal of ectopic pregnancies while preserving a concurrent intrauterine pregnancy, owing largely to it's minimally invasive nature [7]. Open surgery remains the standard of care for ruptured or haemodynamically unstable tubal heterotopic pregnancies [8]. Given the rarity of documented pre‐rupture sonographic diagnosis of a live heterotopic pregnancy with concurrent laparoscopic management and intrauterine pregnancy preservation, this case contributes a clinically valuable example to the existing literature [9, 10, 11].

2. Case History/Examination

A 33‐year‐old para 3 with three previous caesarean sections presented to the gynaecology assessment unit with lower abdominal pain at 5–6 weeks' gestation. Her history included smoking, multiparity, previous pelvic surgery, and a family history of diabetes mellitus. Group B Streptococcus (GBS) positivity was noted incidentally on vaginal swab; while GBS colonisation is not an established independent risk factor for heterotopic pregnancy, it may be associated with ascending genital tract infection and pelvic inflammatory changes that could theoretically predispose to abnormal implantation [12]. Serum β‐hCG was 33,723 IU/L.

On examination, the patient was haemodynamically stable with mild lower abdominal tenderness. There was no peritonism or signs of haemoperitoneum. Transvaginal ultrasound showed a viable intrauterine pregnancy with a yolk sac and a 3.4 mm fetal pole with cardiac activity, corresponding to 6.0 weeks' gestation (Figures 1, 2). The sonographer then performed a systematic and thorough bilateral adnexal sweep, maintaining a high index of suspicion despite the confirmed intrauterine gestation. Adnexal assessment identified a 19 × 17 mm heterogeneous mass in the left adnexa containing a yolk sac and a 5.0 mm fetal pole with cardiac activity, consistent with a live around 6 week ectopic pregnancy (Figures 1, 3). The left adnexal mass was clearly separate from the ipsilateral ovary, demonstrating the “ring of fire” pattern on colour Doppler assessment, with increased peripheral vascularity surrounding the gestational sac. The simultaneous presence of a viable early intrauterine gestation and a left adnexal ectopic gestation confirmed a live heterotopic pregnancy.

FIGURE 1.

Transvaginal ultrasonography demonstrating a heterotopic pregnancy. The left image shows an intrauterine gestational sac with a visible yolk sac (and early embryonic structure), consistent with an early viable intrauterine pregnancy. The right image shows a left adnexal mass labelled “LIF,” characterized by a complex cystic structure with multiple anechoic areas and peripheral vascularity on Doppler assessment, separate from the ovary, consistent with a concurrent ectopic pregnancy.

FIGURE 2.

Transvaginal ultrasound demonstrating an early intrauterine pregnancy. A well‐defined intrauterine gestational sac is visualized within the endometrial cavity, containing a yolk sac and embryo. The crown–rump length (CRL) measures 3.4 mm, corresponding to a gestational age of approximately 6 weeks 0 days (±4 days).

FIGURE 3.

Transvaginal ultrasonography of the left adnexa (LIF) demonstrating a tubal ectopic gestation. A well‐defined gestational sac containing an embryo is visualized outside the uterine cavity. The crown–rump length (CRL) measures 5.0 mm, corresponding to a gestational age of approximately 6 weeks 1 day (±4 days). Color Doppler demonstrates peripheral vascularity consistent with an active ectopic gestation.

3. Differential Diagnosis, Investigations and Treatment

3.1. Differential Diagnosis

The differential diagnosis of a left adnexal mass in early pregnancy includes haemorrhagic corpus luteum, ovarian cyst, tubo‐ovarian pathology, and ectopic pregnancy. The presence of visible embryonic cardiac activity within a discrete adnexal mass separate from the ovary, combined with a confirmed intrauterine pregnancy, was diagnostic of heterotopic pregnancy. Corpus luteum cysts were excluded by the absence of internal echogenicity and the clearly separate location of the mass from the ovary. Ovarian torsion was not suspected given the absence of clinical features and the presence of peripheral Doppler flow.

3.2. Investigations

Serum β‐hCG was 33,723 IU/L, which corresponded appropriately to the gestational age of the intrauterine pregnancy. Serial β‐hCG measurements were not required given the definitive sonographic diagnosis. Full blood count, group and save, and routine pre‐operative bloods were performed. Transvaginal ultrasonography was the principal diagnostic modality, with color Doppler imaging used to characterize adnexal vascularity.

3.3. Treatment

Given the confirmed cardiac activity in the ectopic sac, the risk of imminent tubal rupture, and the patient's clinical stability, the multidisciplinary team counselled the patient regarding the diagnosis, surgical risks including potential loss of the intrauterine pregnancy, and the importance of prompt intervention. Methotrexate was contraindicated given the concurrent viable intrauterine pregnancy. The patient provided informed consent for laparoscopic management.

Laparoscopic surgery was performed with the patient in the Trendelenburg position under general anesthesia. A left tubal ectopic pregnancy was confirmed at laparoscopy, with no evidence of tubal rupture or haemoperitoneum. Left laparoscopic salpingectomy was performed without uterine manipulation, using bipolar diathermy and sharp dissection. The patient recovered well and was discharged the following day.

4. Conclusion and Results (Outcome and Follow‐Up)

A follow‐up transvaginal ultrasound performed 10 days postoperatively confirmed an ongoing viable intrauterine pregnancy with appropriate fetal cardiac activity. The intrauterine pregnancy is currently ongoing; delivery has not yet occurred at the time of submission.

Heterotopic pregnancy is a rare but potentially life‐threatening condition that requires both clinical expertise and keen diagnostic vigilance. In pregnant patients presenting with vaginal bleeding or abdominal pain, clinicians must maintain a high index of suspicion for heterotopic pregnancy, even when an intrauterine pregnancy has been confirmed. Systematic bilateral adnexal evaluation at the time of early pregnancy ultrasound is essential and should not be omitted simply because an intrauterine gestational sac is identified. Prompt surgical management, combined with careful transvaginal ultrasonography, is essential to prevent complications and to safeguard the concurrent intrauterine pregnancy. This case reinforces that early pre‐rupture diagnosis through thorough sonographic assessment, followed by timely laparoscopic salpingectomy, can preserve the intrauterine pregnancy and avoid life‐threatening maternal morbidity.

5. Discussion

Heterotopic pregnancy (HP) is the simultaneous occurrence of an intrauterine pregnancy (IUP) and an ectopic pregnancy (EP). The first reported case was identified in 1708 during an autopsy [9]. HP is rare but potentially life‐threatening and may occur spontaneously or in association with assisted reproductive technology (ART) [13]. Over 90% of HP cases involve the fallopian tube [10]. Risk factors for EP and HP include pelvic inflammatory disease, previous ectopic pregnancies, prior tubal surgery, endometriosis, intrauterine device use, maternal age over 35 years, smoking, and infertility treated with ART [12]. In this case, the patient was a 33‐year‐old at approximately 5–6 weeks' gestation who presented with lower abdominal pain. Her identifiable risk factors included smoking, multiparity, and previous pelvic surgery (three caesarean sections).

Timely diagnosis of HP is critical for the prognosis of both mother and fetus, as delays or misdiagnosis increase the risk of morbidity and mortality [11]. Although symptoms such as abdominal pain, vaginal bleeding, or rectal tenesmus may facilitate earlier diagnosis, these are infrequently observed in HP because of the concurrent intrauterine pregnancy [14]. β‐hCG levels are not reliably diagnostic in heterotopic cases because the coexisting IUP affects these values, though markedly elevated β‐hCG levels may raise clinical suspicion [14]. In this case, the patient's β‐hCG level corresponded appropriately to the gestational age of the intrauterine pregnancy, demonstrating that a normal or expected value does not exclude the presence of a concurrent ectopic gestation. This limitation underscores the critical importance of a careful and systematic adnexal assessment, even when a viable intrauterine pregnancy has been confirmed on ultrasound.

Several factors contributed to the early pre‐rupture diagnosis in this case. First, the sonographer performed a dedicated bilateral adnexal sweep despite the presence of a confirmed intrauterine pregnancy. Second, the left adnexal mass was clearly separate from the ovary, with visible embryonic cardiac activity, allowing definitive characterization rather than misinterpretation as a haemorrhagic corpus luteum or ovarian cyst. Third, the clinical context of abdominal pain in early pregnancy maintained a high index of suspicion throughout the assessment. This systematic approach directly enabled the pre‐rupture identification of the ectopic gestation, which is the cornerstone of the clinical lesson offered by this report.

Transvaginal ultrasonography is a valuable tool for the early diagnosis of HP. However, gestational sacs may be misinterpreted as haemorrhagic corpora lutea or ovarian cysts, particularly in patients undergoing ART [15]. Persistent enlargement of an adnexal fluid collection with increased vascularity should raise suspicion for an early ectopic pregnancy. Even when an intrauterine pregnancy is confirmed, careful transvaginal ultrasonography with systematic adnexal evaluation is essential to exclude a concurrent ectopic gestation [16]. In this case, ultrasonography demonstrated an intrauterine gestational sac with a visible yolk sac alongside a left adnexal mass characterized by a complex cystic structure with multiple anechoic areas, separate from the ovary, with Doppler evidence of peripheral vascularity, indicative of a concurrent tubal ectopic pregnancy. The presence of visible embryonic cardiac activity within the adnexal mass was the decisive finding that enabled pre‐rupture diagnosis.

Comparing this case to previously reported cases in the literature further contextualizes its significance. Cucinella et al. [10] described early surgical management of HP allowing preservation of the IUP, emphasizing the value of prompt intervention. Similarly, Ge et al. [5] reported a single‐institution series of 65 cases, noting that early diagnosis was the strongest predictor of a favourable intrauterine outcome. Sullivan and Clem [8] and Areys et al. [11] both reported cases where delayed diagnosis led to tubal rupture, reinforcing the clinical value of systematic adnexal scanning. In contrast to these reports, the present case is notable for the sonographic identification of dual embryonic cardiac activity—both intrauterine and ectopic—at a pre‐rupture stage in a spontaneously conceived pregnancy, followed by uncomplicated laparoscopic management with preservation of the intrauterine gestation.

Laparoscopic salpingotomy or salpingectomy is a safe and effective approach for the management of tubal ectopic pregnancies and does not appear to increase the risk of loss of a concurrent intrauterine pregnancy [7]. Tubal heterotopic pregnancies generally demonstrate higher live birth rates than interstitial ectopics. For tubal ectopic pregnancies, management options include salpingectomy, salpingostomy, or less commonly, tubal anastomosis, with comparable subsequent fertility outcomes. In this case, a laparoscopic salpingectomy was performed without manipulation of the uterus. The patient experienced an uncomplicated recovery and was discharged the following day. The intrauterine pregnancy is currently ongoing at the time of submission.

Transabdominal, sonographically guided aspiration of the ectopic gestation, with or without the use of embryo‐toxic agents, represents an alternative approach for managing the ectopic component in HP. This minimally invasive technique has a well‐established safety and efficacy profile [17]. However, it can be technically challenging depending on the location of the ectopic sac and should only be undertaken when the sac is clearly visualized [13]. Potassium chloride and hyperosmolar glucose are considered appropriate embryo‐toxic agents for this indication, whereas methotrexate is contraindicated due to its teratogenic effects on the concurrent viable intrauterine pregnancy [18].

Author Contributions

Natalia Price: writing – review and editing, project administration, supervision, validation, investigation, conceptualization, methodology. Abdulrahman Ehab Alsaggaf: conceptualization, investigation, data curation, writing – review and editing, writing – original draft, visualization, methodology.

Funding

The authors have nothing to report.

Consent

Written informed consent from the patient was obtained according to journal guidelines.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.