A case report of miliary tuberculosis diagnosed in the peripartum period

Case presentation

A 38-year-old female, transferred her antenatal care at 34 weeks of gestation to our maternity unit in April 2025 because she had moved house. She had had one early missed miscarriage treated surgically, and a previous pregnancy with elective caesarean delivery. She was allocated consultant-led care in view of her extensive medical and surgical histories, including a longstanding diagnosis of Crohn's disease.

She was diagnosed with Crohn's disease at the age of 20. Due to poor response to medical management, she underwent a laparoscopic right hemicolectomy at the age of 21 which was a pioneering surgical approach at the time. Histology formally confirmed terminal ileum Crohn's disease. Since her procedure her Crohn's disease had been well-controlled, originally on azathioprine 25 mg daily and allopurinol 100 mg daily. Though a recurrence at the anastomotic site was noted on MRI scan in 2011, it remained clinically quiescent with no significant flares reported from 2013, apart from episodic abdominal cramps. The anti-TNF agent adalimumab was added to her treatment following a repeat bowel MRI scan and colonoscopy and normal chest X-ray. The latest result of faecal calprotectin was 68 mcg/g, which was regarded as a negative result for inflammation (commonly, level > 150 mcg/g indicates active inflammatory bowel disease). Blood tests showed a borderline low iron and Vitamin D level which was treated with a 12-week course of iron (ferric maltol 30 mg orally once daily) and a regular Vitamin D3 tablet containing 800 to 1000 international units (equivalent to 20–25 mcg/day).

She remained mainly asymptomatic from her Crohn's disease during the current pregnancy. Upon presentation to the antenatal clinic at 36 weeks of gestation, she complained of feeling intermittently hot and cold with night sweats, and persistent fatigue. She was twice subsequently admitted to the antenatal ward with pyrexia of unknown origin. Initial working diagnoses included viral respiratory tract infection or urinary tract infection. Subsequent urine cultures were negative.

The first graph (Figure 1) depicts the fluctuation of CRP levels over a period of 4 months with a representative stretch during the patient's hospital admission from 14/5/25 to 02/06/25. The CRP remained high (77–147 mg/L, with a mean of 108 mg/L), despite the patient receiving intravenous (IV) broad-spectrum antibiotics.

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Figure 1.

CRP levels in mg/L (from October 2024 to August 2025).

She was prescribed broad-spectrum IV antibiotics, initially clindamycin and metronidazole and then vancomycin and gentamicin. Following 2 weeks of persistent symptoms, she contacted her inflammatory bowel disease (IBD) team in her original hospital, who advised cessation of adalimumab due to her deteriorating condition.

At 37 weeks and 3 days of gestation, she developed a high-grade pyrexia of 40 °C and significant maternal and fetal tachycardia. She went into spontaneous labor but failed to progress after 6 hours of regular uterine contractions. An emergency caesarean section was performed under general anesthesia, due to suspected chorioamnionitis, attended by senior obstetric and anesthetic teams. A live female infant was delivered, weighing 3100 g, with Apgar scores of 9 at 1 minute and 10 at 5 minutes and measured blood loss of 160 ml. Postoperatively, the patient initially recovered well. However, she developed recurrent pyrexia overnight with elevated Maternity Early Warning Score scores. She was transferred to the High Dependency Unit on Labour Ward for one-to-one monitoring. A CT chest, abdomen, and pelvis was requested and performed on day 2 postoperatively (Figure 2). This revealed disseminated bilateral tiny pulmonary lymph nodes with mediastinal lymphadenopathy and splenomegaly.

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Figure 2.

CT chest showing bilateral pulmonary lymph nodes and mediastinal lymphadenopathy.

Differential diagnoses considered at this stage included: septic emboli, lymphoma, acute granulomatous disease (tuberculosis [TB] or sarcoidosis) or immune mediated disease. Urgent consultations were sought with respiratory and hematology specialists, as well as the on-call regional obstetric physician. The on-call respiratory consultant advised an urgent supraclavicular lymph node biopsy for microscopy, culture, sensitivity, and histology and forced sputum collection. The CT scan findings were discussed and reviewed at the radiology multidisciplinary team meeting. It was felt that TB was likely as the small pulmonary lymph nodes looked necrotic on the CT chest.

On day 4 into her postnatal course, six lymph node biopsies were obtained and sent for analysis. The patient remained on IV antibiotics and symptomatic management. Despite this, she continued to experience swinging fevers and night sweats. The case was discussed at the Regional Maternal Medicine MDT on day 11 into her postnatal course.

Microbiological results including rapid nucleic acid amplification tests confirmed a diagnosis of TB and revealed a low level of mycobacterium TB, scanty acid-fast bacilli (AFB) and no rifampicin resistance. Anti-TB treatment was initiated promptly in coordination with the respiratory and community TB teams. She was commenced on standard four-drug anti-TB therapy (a combination of rifampicin, isoniazid, pyrazinamide, and ethambutol) for 2 months, along with pyridoxine supplementation for 6 months. A structured outpatient follow-up plan was implemented by community TB and respiratory services. The baby girl was also extensively tested for TB; all tests came back negative. She remains well, growth on normal centile and received anti-TB prophylaxis.

Discussion

This case illustrates the diagnostic complexity of TB during the peripartum period, and importance of considering TB in the differential diagnosis of pyrexia of unknown origin in pregnancy and postpartum, particularly in immunosuppressed patients.^1,2 Anti-TNF therapy such as adalimumab increases the risk of TB reactivation, often presenting in disseminated or extra-pulmonary forms like miliary TB. The altered immune state of pregnancy and postpartum can obscure classical signs, contributing to the delay in diagnosis.

In the cohort of patients who are receiving anti-TNF therapies the risk of new TB and latent TB reactivation is significantly higher than in the general population.^3,4 Therefore, the standard approach for clinicians who are initiating treatment with biologics is to follow a checklist of tests which have to be completed prior to commencing the patient on these medications. In this case, subsequent enquiry with her IBD team revealed that TB screening had been limited to a plain chest radiograph but not an interferon-gamma release assay test.

The local hospital where this patient was managed for IBD has recently begun revising its guidelines to standardize the investigations required before prescribing biologics, in line with newly emerging evidence. In summary, the following list of pre-assessment history and specialist investigations should include.^5,6

Detailed personal history of infections, symptoms/exposure/contact for TB, Herpes Zoster, Varicella Zoster Virus.

Interestingly, review of existing guidelines from various specialties where the question of screening and pre-medication check-ups are normally arranged prior to starting biologics, we have noted that there is no consensus on the list of required testing, with wide variations in practice not only inter-specialities but also between individual clinicians. So, the need for having a standardized pre-treatment protocol, prior to commencing such treatment, is vital.^7,8

The diagnosis of TB was not considered pre-delivery and had this happened preterm the outcome may not have been so good. A wide differential for pyrexia of unknown origin and appropriate investigation including a chest X-ray should be practiced. Prompt multidisciplinary coordination in postnatal period and access to molecular diagnostics were critical in establishing the diagnosis and initiating timely treatment, likely contributing to a favorable outcome for both mother and infant.

Conclusion

Miliary TB remains a diagnostic challenge in the peripartum period, especially in patients on immunosuppressive agents. Clinicians must maintain a high index of suspicion in patients with systemic symptoms, especially when routine infections are ruled out. Early imaging, biopsy, and molecular testing play a key role in diagnosis and management. This case also highlights the importance of following a standardized screening protocol before commencing any biologic therapy to reduce the risk of new diagnosis and/or latent TB reactivation and to some extent, the introduction of a unified protocol which can be used interchangeably between various specialties.