Biopsy During Pregnancy: Safety and Recommendations
Image-guided core biopsy can be safely performed during pregnancy when clinically indicated, with minimal risk to both mother and fetus, and should not be delayed when necessary for diagnosis of suspected malignancy. 1
Breast Biopsy During Pregnancy
Image-guided core biopsy is the preferred diagnostic method when breast imaging demonstrates a suspicious mass during pregnancy. 1 The procedure should be performed after initial diagnostic imaging evaluation, not as the first-line assessment of a palpable mass, as post-biopsy changes may obscure lesion visualization. 1
Key Safety Considerations for Breast Biopsy:
- Informed consent should include discussion of low risk of milk fistula and increased risk of bleeding in pregnant and lactating women. 1
- If initial imaging does not demonstrate etiology for a clinically suspicious mass, non-image-guided biopsy should be performed via palpation. 1
- Fine-needle aspiration is less preferred than core biopsy, as it may cause post-aspiration changes that obscure visualization. 1
Sentinel Lymph Node Biopsy:
Sentinel lymph node biopsy can be safely performed during pregnancy using low-dose technetium-99m labeled albumin nanocolloid (average 10 MBq). 1 Almost 90% of this dose is collected in the sentinel node, resulting in minimal systemic exposure and negligible fetal risk. 1 The largest series of 145 pregnant breast cancer patients who underwent sentinel lymph node biopsy reported no neonatal adverse events related to the procedure. 1
Blue dye (isosulfan blue or methylene blue) should be avoided during pregnancy due to risk of anaphylactic reaction. 1
Cervical Biopsy During Pregnancy
Colposcopy and cervical biopsy during pregnancy should be performed when high-grade neoplasia or invasive cancer is suspected. 1 Low-grade squamous intraepithelial lesions (LSIL) and atypical squamous cells of undetermined significance (ASC-US) can be deferred until 6 weeks postpartum. 1
Critical Cervical Biopsy Guidelines:
- Endocervical curettage (ECC) should NOT be performed during pregnancy to avoid possible disruption of the pregnancy. 1
- Brush cytology is safe during pregnancy and can be used as an alternative. 1
- Directed cervical biopsy has minimal complications, with hemorrhage requiring vaginal packing occurring in only 0.6% of cases (1 of 176 patients). 2 Premature labor is not more frequent after biopsy. 2
- Biopsy is justified when either cytology or colposcopy suggests at least high-grade CIN, to ensure no cancer has been overlooked. 2
- Diagnostic limited excisional procedure (conization) is recommended only if invasive cancer is suspected, and consultation with an experienced colposcopist should be considered. 1
For cervical cancer staging, lymphadenectomy can be performed up to the 22nd week of gestation, with laparoscopy preferred before 14-16 weeks and laparotomy reserved for cases beyond this timeframe. 1 Nodal resection is not recommended after the 22nd week as insufficient nodes can be retrieved. 1
Other Organ Biopsies During Pregnancy
Liver Biopsy:
According to the American College of Gastroenterology, liver biopsy can be effectively and safely conducted in pregnant women when biopsy results affect timing of delivery or choice of medical therapy. 3 Conventional routes include percutaneous, transjugular, and surgical methods. 3 Adverse events are limited to abdominal pain, hemorrhage, and increased risk of preterm birth or small for gestational age neonate. 3
Renal Biopsy:
Renal biopsy during pregnancy has a very low complication rate (4.5%) and yields definitive histological diagnosis in almost all cases. 4 In a series of 111 renal biopsies performed in 104 pregnant women, the procedure was concluded to be safe. 4
Common Pitfalls to Avoid
- Do not perform image-guided biopsy as the initial evaluation of a palpable breast mass, as post-biopsy changes may interfere with subsequent imaging interpretation. 1
- Do not use blue dye for sentinel lymph node mapping due to anaphylaxis risk. 1
- Do not perform endocervical curettage during pregnancy to avoid pregnancy disruption. 1
- Do not delay necessary biopsies out of excessive caution, as diagnostic delays can compromise maternal outcomes without improving fetal safety. 1