Introduction

Colposcopy in pregnancy presents a distinct clinical challenge. It requires balancing accurate assessment of cervical pathology with the safety of both mother and fetus, while also addressing the anxiety that often accompanies a potential cancer diagnosis during pregnancy. Although the basic principles of colposcopy remain unchanged, pregnancy introduces anatomical and physiological changes that warrant a more cautious and considered approach.

The primary aim of colposcopy in pregnancy differs from that in the non-pregnant setting. Rather than definitive diagnosis and treatment of pre-invasive disease, the focus is on excluding invasive cancer. This shift in priority determines all aspects of clinical decision-making, including examination technique, biopsy, surveillance, and timing of treatment.¹

Indications for Colposcopy in Pregnancy

Pregnancy provides an important opportunity to screen individuals who may otherwise be under- or never-screened. The indications for colposcopy are broadly consistent with those in non-pregnant, asymptomatic patients, as outlined in the Australian Cervical Screening Guidelines.²

Referral is appropriate for abnormal screening results, as well as for patients presenting with symptoms suggestive of cervical malignancy or visible suspicious lesions. However, once a patient is referred, management priorities shift. The goal is no longer accurate diagnosis of cervical intraepithelial neoplasia (CIN) or immediate treatment, but rather the timely exclusion of invasive disease. This approach minimises unnecessary intervention while maintaining maternal and fetal safety.

Physiological Changes and Their Impact on Colposcopy

Pregnancy induces a range of physiological changes in the cervix and vagina that can significantly complicate colposcopic assessment. These include increased vascularity, stromal oedema, cervical ectropion, glandular hyperplasia, increased mucus production, and decidualisation of cervical and vaginal tissues.

Decidual changes may become extensive, sometimes covering the entire vaginal portion of the cervix, particularly in the second and third trimesters (Figure 1). Vaginal wall laxity can further impair visualisation, and patient discomfort or anxiety may limit examination quality.

Fig. 1. Colposcopy at 25 weeks pregnant. Low power (A) and high power (B). 1. High-grade dysplasia. 2. Decidual changes.

These changes reduce the diagnostic accuracy of colposcopy compared with the non-pregnant state.³ Increased vascularity may mimic abnormal neovascular patterns, glandular proliferation can obscure lesion margins, and decidualised tissue may resemble high-grade disease or even invasive cancer. As a result, there is a risk of both overestimation and underestimation of disease severity.

Recognising these physiological alterations is essential to avoid misinterpretation and inappropriate intervention. Experience in colposcopy is particularly important in this context.

Safety and Technique

Colposcopy is safe in pregnancy when performed appropriately and is not associated with an increased risk of miscarriage or preterm labour.⁴ However, modifications to technique are required to optimise both safety and diagnostic yield.

Examination should ideally be performed by an experienced colposcopist using a gentle approach. A wider speculum may assist visualisation, particularly in the presence of vaginal wall laxity. Additional lateral support can be achieved using vaginal retractors or simple techniques such as placing a latex sheath over the speculum blades.

The procedure should be kept as brief as possible to minimise patient discomfort and reduce the risk of supine hypotension. Liberal use of acetic acid is helpful in clearing mucus and improving visualisation of the transformation zone. Care should be taken when using swabs, as the cervix is often friable and prone to bleeding.

Cervical screening tests may be repeated if required. However, endocervical sampling with an endocervical brush is generally avoided due to the potential for bleeding and limited additional diagnostic value in this setting.

Role of Biopsy

Cervical biopsy can be safely performed during pregnancy, but its use should be judicious. The primary indication for biopsy is suspicion of invasive or microinvasive disease.

Routine biopsy to confirm low- or high-grade lesions in the absence of concerning features is not recommended. It does not alter management and may increase patient anxiety. Instead, colposcopic assessment should focus on identifying features suggestive of invasion, such as friable abnormal vessels, irregular or uneven surfaces, exophytic growths, necrosis, ulceration, or visible tumour deposits (Figure 2).

Fig. 2. Colposcopy at 30 weeks pregnant, high power. 1. Suspicious of invasive cancer. 2. High-grade dysplasia.

When findings are equivocal, early consultation with an experienced colleague is advisable. If invasion cannot be confidently excluded with directed biopsy, a diagnostic excisional procedure – such as a wedge or cone biopsy – may be required to obtain adequate tissue. These procedures should be performed in a controlled setting, typically in an operating theatre, with multidisciplinary involvement including gynaecological oncology and maternal fetal medicine specialists.

Endocervical curettage is absolutely contraindicated in pregnancy due to the risk of disrupting the pregnancy.

Management During Pregnancy

In the absence of suspected invasion, management of CIN during pregnancy is conservative.

Low-grade lesions generally require no further antenatal assessment, with follow-up deferred until after delivery. High-grade lesions warrant surveillance with repeat colposcopy at intervals of approximately 12–16 weeks to monitor for progression.

Photographic documentation is particularly valuable in this setting, allowing for comparison over time and reducing interobserver variability.

Progression of CIN to invasive cancer during pregnancy is rare. In contrast, spontaneous regression following delivery is relatively common, particularly in cases of low-grade disease.⁵ These observations support a conservative approach, with treatment deferred until the postpartum period unless there is clear concern for invasive disease.

Postpartum Assessment and Management

Postpartum reassessment is a critical component of care and should be anticipated at the time of initial evaluation. Colposcopy is typically performed at least 6-12 weeks after delivery, allowing time for cervical involution and improved visualisation.

At this stage, biopsy can be performed more freely if indicated. In breastfeeding patients, short-term use of topical vaginal oestrogen prior to assessment can improve epithelial maturation and enhance examination quality.

Definitive treatment of persistent high-grade lesions can then be undertaken following histological confirmation. This approach ensures that treatment is both necessary and appropriately timed, minimising risk to the patient.

Conclusion

Colposcopy in pregnancy is a safe and valuable diagnostic tool when used appropriately. The key objective is the exclusion of invasive disease while avoiding unnecessary intervention.

Pregnancy-related cervical changes can significantly affect interpretation and require both experience and caution. Biopsy should be reserved for cases where invasion is suspected, and endocervical curettage must be avoided.

Most cases of CIN can be managed conservatively during pregnancy, with definitive treatment deferred until after delivery. This approach optimises outcomes for both mother and fetus while maintaining diagnostic vigilance.