Incidental findings of ipsilateral agenesis of the ovary and fallopian tube during cesarean section delivery successfully managed in a resource-limited setting: a case report

Abstract

Introduction and importance:

Unilateral agenesis of the ovary and fallopian tube is a rare reproductive anomaly that may occur with or without associated uterine malformations. Both variations have been reported in the literature. As patients are often asymptomatic, diagnosis typically occurs incidentally during surgery. This case presents a rare combination of ipsilateral ovarian and fallopian tube agenesis with a unicornuate uterus and normal bilateral kidneys. It underscores the need for a multidisciplinary approach involving obstetricians, neonatologists, and nursing care to improve maternal and neonatal outcomes.

Clinical presentation:

A 27-year-old Black African primigravida at 40 weeks of gestation was admitted with 2 hours of pushing-down pain. She had regular antenatal care at a local health center but no ultrasound due to limited resources. On arrival, obstetric ultrasound with Doppler revealed intrauterine growth restriction and abnormal blood flow. Cardiotocography showed minimal variability with recurrent decelerations, prompting an emergency Cesarean section.

Clinical Discussion:

Congenital unilateral absence of the fallopian tube with ipsilateral ovarian agenesis is rare and may or may not involve uterine or renal anomalies. These conditions can affect pregnancy outcomes, potentially leading to miscarriage or stillbirth. Nonetheless, cases of full-term delivery have been documented.

Conclusion:

This rare anomaly can occur with or without additional reproductive or renal abnormalities. Although it may increase pregnancy risks, successful term deliveries are possible. Early diagnosis and careful monitoring are crucial for favorable outcomes. Further research is needed to improve the understanding and management of this condition.

Background

Congenital unilateral absence of the fallopian tube with ipsilateral ovarian agenesis is a rare condition, with an estimated incidence of 1 in 11 240 cases^[1]. Unilateral ovarian agenesis (UOA) and absence of the fallopian tube are also considered very rare congenital anomalies^[2].

This case is reported according to the SCARE guideline^[3].

HIGHLIGHTS

• Unilateral agenesis of the ovary and fallopian tube is an unusual phenomenon.

• This condition may occur with or without an associated uterine anomaly, and in both cases, it is typically asymptomatic, making diagnosis an incidental intraoperative finding.

• In resource-limited settings, the absence of advanced diagnostic tools such as ultrasound and hysterosalpingography further complicates detection.

• Although women with this anomaly may experience uncomplicated pregnancies, cases of recurrent miscarriage and infertility have been reported.

• A multidisciplinary approach is essential to improving patient outcomes.

Clinical presentation

A 27-year-old Black African primigravida at 40 weeks of gestation was admitted to the Obstetrics and Gynecology Department with complaints of pushing-down pain for the past 2 hours. She had attended regular antenatal care follow-up at a nearby health center, where she received routine care; however, no ultrasound examination had been performed due to the unavailability of the service. When she presented to the health center with pushing-down pain, she was referred to our facility for further evaluation.

On arrival, she was in active labor with stable vital signs: blood pressure 115/75 mmHg, pulse rate 84 beats per minute, respiratory rate 20 breaths per minute, and temperature 36.7 °C. Anthropometric assessment revealed a body mass index (BMI) of 26.7 kg/m². Systemic examination findings were within normal limits.

On abdominal examination, the uterus corresponded to a 34-week size, with a longitudinal lie and cephalic presentation. The fetal heart rate (FHR) was 130 beats per minute. Pelvic examination revealed a cervix dilated to 2 cm, 80% effaced, and station −1, with intact membranes.

Obstetric ultrasound demonstrated a singleton pregnancy in cephalic presentation, an amniotic fluid index of 6 cm, and an estimated fetal weight of 2.3 kg (below the 3rd percentile), with a normal FHR. Doppler studies revealed a middle cerebral artery pulsatility index above the 97th percentile, and cardiotocography showed minimal variability with recurrent decelerations, indicating a pathological tracing.

Based on these findings, the patient was diagnosed with a full-term pregnancy in the first stage of labor, intrauterine growth restriction (IUGR), and abnormal Doppler findings, and was admitted to the labor ward. After discussing the results with the patient and her family, an emergency cesarean section was performed, delivering a 2.2-kg female neonate.

Intraoperatively, a unicornuate uterus was observed, along with agenesis of the right ovary and fallopian tube (Fig. 1). Both kidneys were normal. Postnatally, an abdominopelvic ultrasound was performed and revealed no abnormalities. The neonate exhibited features of IUGR but no other congenital anomalies. She was evaluated with a neonatologist, passed urine at 14 hours of age, and underwent an ultrasound scan, which was normal.

Figure 1.

Illustration of absent right ovary and fallopian tube.

After 3 days of hospitalization, the mother was discharged with advice on breastfeeding, vaccination, and neonatal hygiene. On subsequent follow-up visits at the outpatient clinic, no new complaints were reported, and she was eventually discharged from follow-up care.

Discussion

Müllerian duct defects are an uncommon cause of infertility in women^[4]. Studies estimate their prevalence to be approximately 4.3% in the general population, 3.5% among infertile women, and 13% in those with recurrent pregnancy loss^[5]. Accurate classification of these anomalies is essential, as obstetric outcomes and available treatment options vary depending on the specific type of defect^[4].

In 1988, the American Fertility Society developed a standardized classification system for Müllerian duct anomalies^[6]. This system (Fig. 2) is based on a fundamental understanding of Müllerian embryology and its correlation with observable anatomy. Key classification criteria include the presence of each segment of the female reproductive tract, the external contour of the uterine fundus, and the presence or absence of a septum^[7]. Müllerian anomalies, as well as congenital agenesis of the ovary and fallopian tube, are often asymptomatic, making diagnosis particularly challenging.

Figure 2.

The Classification System of Müllerian Duct anomalies by the American Fertility Society.

Although the number of reported cases is limited, most are incidentally diagnosed during laparoscopy performed for gynecological or obstetric indications^[8]. Unilateral adnexal agenesis is frequently associated with uterine malformations, such as a unicornuate uterus, and unilateral renal agenesis. Stuti et al^[9] reported a case of a woman with a unicornuate uterus and UOA. Congenital absence of an ovary and its corresponding fallopian tube – clinically referred to as unilateral adnexal agenesis – is an exceptionally rare developmental anomaly^[1,10].

In our case, the patient presented with a unicornuate uterus and unilateral ovarian and fallopian tube agenesis, but with normal kidneys, making this presentation particularly uncommon.

The precise etiological factors underlying the absence of ipsilateral ovarian and tubal structures remain largely unclear^[11]. However, three main hypotheses have been proposed based on documented case reports. The first is adnexal torsion; the second involves maldevelopment of the tube and ovary secondary to reduced blood flow from a vascular event; and the third relates to a developmental defect of the Müllerian and mesonephric systems, which may affect only one side or be localized to the genital ridge and its lower segment^[12,13].

The adnexal torsion hypothesis describes a condition that typically presents with severe abdominal pain in later life but can also occur during pregnancy, childhood, and, interestingly, even during fetal development^[12,14,15].

In our case, there was no documented history of acute abdominal pain; however, the absence of symptoms does not rule out the possibility of torsion occurring in utero.

The second hypothesis concerns the developmental processes of the reproductive organs. During embryogenesis, the uterus and fallopian tubes arise from the paramesonephric ducts, whereas the ovaries develop from the urogenital ridge, with germ cells originating from the yolk sac. Disruptions in the development or resorption of these embryonic structures may lead to agenesis of the fallopian tubes and ovaries, a condition frequently associated with renal anomalies^[11,16].

The final hypothesis suggests that a vascular event may play a crucial role in the development of unilateral adnexal agenesis. Specifically, inadequate blood supply to the upper segments of the Müllerian ducts during early gestation could disrupt autocrine and paracrine signaling pathways, ultimately causing the absence of gonadal structures and malformations of the reproductive tubes^[17,18].

Paternoster et al^[19] reported two cases involving the absence of fallopian tubes and proposed that partial or complete unilateral defects of the paramesonephric duct occur more frequently than aplasia of both ducts. Consequently, the presence of a unicornuate uterus, a single fallopian tube, and a rudimentary or ectopic kidney suggests a developmental defect affecting all Müllerian structures.

Compared to Müllerian duct–derived organs, congenital defects of the ovary are exceedingly rare. Gonadal development relies on precise germ cell migration and proper formation of the urogenital ridge. These processes are regulated by multiple genetic and molecular factors^[20], and a unilateral disruption at any stage may impede ovarian formation. The coexistence of UOA with an ipsilateral fallopian tube and a unicornuate uterus is exceptionally uncommon^[10,16].

Our patient presents with a rare combination of anomalies: unilateral agenesis of the fallopian tube and a unicornuate uterus due to a Müllerian anomaly, along with unilateral gonadal agenesis. Embryologically, the Müllerian duct arises from the intermediate mesoderm of the urogenital ridge, whereas the ovaries develop from the gonadal (genital) ridge. Consequently, our patient exhibits anomalies in both the urogenital ridge and the gonadal ridge, two rare events occurring in a single individual, making this case particularly noteworthy. Furthermore, the presence of a normal bilateral renal system alongside unilateral adnexal agenesis represents another unusual finding.

While unilateral adnexal agenesis associated with renal anomalies and UOA has been documented in the literature, to the best of our knowledge, the combination of these anomalies with an otherwise normal bilateral renal system, as observed in this case, has not been previously reported.

Historically, these anomalies have been identified using hysterosalpingography^[5]. However, hysterosalpingography only assesses the uterine cavity and tubal patency, limiting the clinician’s ability to evaluate the external uterine contour^[5]. Ultrasound (US) complements hysterosalpingography by enabling visualization of the external contour, but it has limitations. Imaging quality can deteriorate with increasing age, BMI, and bowel gas interference, making it difficult to clearly visualize the external contour^[5,21].

The primary clinical manifestations of Müllerian anomalies include primary amenorrhea, dysmenorrhea, pelvic pain, endometriosis, sexual difficulties, and reduced self-esteem^[22].

According to Friedman et al^[23], over 30% of patients with unilateral renal agenesis have an associated Müllerian anomaly. However, diagnosis in this population is often delayed until after menarche, when complications from retrograde menstruation due to obstructive anomalies result in significant issues such as endometriosis, pelvic inflammatory disease, and infertility. Currently, no clear guidelines exist for communication among the antenatal sonographer, obstetrician, parents, and the child’s pediatrician, creating barriers to effective screening and follow-up. Furthermore, there are no established guidelines for screening women with specific renal anomalies for associated Müllerian anomalies.

Cahen-Peretz et al^[24] reported that among 256 299 deliveries (1991–2013), 0.49% involved women with Müllerian anomalies. These anomalies were independently associated with higher risks of placental abruption, IUGR, abnormal fetal presentation, and cesarean delivery.

Regarding UOA, fertility is generally minimally affected or not affected at all in women with the absence of one ovary^[25]. This is likely because the presence or absence of anomalies in the contralateral ovary is a key determinant of reproductive capacity^[26]. Although unilateral adnexal anomalies and ovarian agenesis can be associated with various complications, our patient did not report any symptoms such as pelvic pain and was able to successfully achieve a live birth.

Conclusion

Müllerian duct anomalies, though uncommon, play a significant role in female infertility and reproductive complications. Accurate classification of these defects is crucial, as it guides treatment options and predicts obstetric outcomes. Unilateral adnexal agenesis, often associated with uterine malformations like a unicornuate uterus, remains a rare and challenging diagnosis, frequently discovered incidentally. While the exact causes are not fully understood, hypotheses include adnexal torsion, developmental disruptions, and vascular incidents during embryogenesis. Improved imaging techniques and multidisciplinary approaches are essential for early detection and optimal management of these complex anomalies.

Ethical approval

Ethical approval for this study was provided by the Ethical Committee of our institution.

Consent

Written informed consent was obtained from the patient for the publication of this case report and any accompanying images. A copy of the written consent is available for review by the corresponding author.

Sources of funding

No funding received.

Author contributions

W.M.D.: Conception, design of the work, acquisition, analysis, interpretation of data, drafting of the work, and revision. L.E.D.: Acquisition, analysis, interpretation of data, drafting of the work, and revision. M.A.W.: Design of the work and acquisition. G.T.A.: Acquisition and analysis. A.A.M.: Analysis and interpretation of data. B.A.M.: Analysis and interpretation of data.

Conflicts of interest disclosure

All authors declare that they have no conflict of interest.

Research registration unique identifying number (UIN)

This is not “First in man work.”

Guarantor

Wondwosen Mengist Dereje.

Provenance and peer review

Not commissioned; externally peer reviewed.