Speculum Types and Sizes: A Complete Guide for UK Clinicians

Cusco, Graves, Pederson, Sims: choosing the right speculum type and size directly affects patient comfort and clinical outcomes. This guide covers every vaginal speculum type used in UK practice, breaks down available sizes by millimetre, and walks through the decision-making process so you can match the instrument to the patient and procedure every time.

Whether you are setting up a cervical screening clinic, ordering for a sexual health service, or simply restocking your examination room, understanding what sets each speculum apart will save time, reduce waste, and improve the patient experience.

In this article

• What is a speculum and what is it used for?
• What are the different types of vaginal speculum?
• What speculum sizes are available?
• UK colour coding: which colour is which size?
• How do you choose the right speculum size?
• Insertion technique: clinical pearls
• What to do when the cervix is not visible
• Disposable vs reusable speculums
• What speculum do you need for cervical screening?
• Frequently asked questions

What is a speculum and what is it used for?

A vaginal speculum is a hinged medical instrument inserted into the vaginal canal to hold the walls apart, giving the clinician a clear view of the cervix and upper vagina. Named after French surgeon Edouard-Gabriel Cusco (1819 to 1894), the modern bivalve design is one of the most commonly used instruments in gynaecology and sexual health.

Speculums are used for a wide range of procedures, including:

• Cervical screening (smear tests) to collect cells from the cervix for HPV and cytology testing
• IUD and IUS insertion and removal, where full cervical visualisation is essential for safe placement
• Colposcopy for detailed examination of the cervix following abnormal screening results
• Swab collection for STI testing and microbiological cultures
• LLETZ / LEEP procedures for excision of abnormal cervical tissue
• Endometrial biopsy and intrauterine procedures such as hysteroscopy
• Assessment of vaginal discharge, bleeding, or prolapse

The instrument has been in clinical use for over 150 years, but modern single-use designs have transformed infection control. Today, most UK clinics use disposable plastic speculums as standard.

What are the different types of vaginal speculum?

Several speculum designs exist, each suited to different clinical scenarios. The table below summarises the main types you will encounter in UK practice.

Type	Blade Design	Self-Retaining?	Best Used For
Cusco (bivalve)	Two hinged, concave blades with a thumbscrew lock	Yes	Cervical screening, IUD insertion, colposcopy, routine examinations. The standard choice for most UK procedures.
Graves	Wider, curved bivalve blades with a broader opening	Yes	Multiparous patients and surgical procedures where maximum exposure is needed. More common in North American practice.
Pederson	Narrow, flat bivalve blades	Yes	Nulliparous patients, post-menopausal patients, and those with narrow vaginal canals. Easier insertion.
Sims (single blade)	Single curved blade, open on one side	No (assistant needed)	Vaginal wall examination, prolapse assessment, surgical procedures requiring lateral wall retraction.
Winterton / Huffman	Very narrow, elongated blades (10 to 15 mm width)	Yes	Adolescent patients and virginal examinations. Minimises discomfort with very narrow introitus.
Paediatric	Miniature bivalve or tubular design	Varies	Examination of young children under specialist supervision only.

Cusco: the UK standard

The Cusco speculum is by far the most widely used type in UK clinical settings. Its self-retaining thumbscrew mechanism means it holds itself in the open position, freeing both of the clinician's hands for sampling, device insertion, or examination. Available in sizes from extra-small to large, the Cusco covers the vast majority of routine gynaecological work.

Modern disposable Cusco speculums are typically made from medical-grade polystyrene or ABS plastic, with a smooth finish to aid insertion. Some models, like the Ultraspec, include an integrated sidewall retractor to prevent lateral vaginal walls from obscuring the cervical view.

The design combines Cusco's original operating principle with T.W. Graves' duckbill blade shape. The modern version features a handle so the lower blade can be held and controlled independently, giving the clinician precise control over the opening angle.

Sims: the surgical workhorse

The Sims speculum uses a single curved blade to retract one vaginal wall at a time. It is the preferred instrument for assessing pelvic organ prolapse, where each compartment (anterior, posterior, apical) must be evaluated independently. Because it does not self-retain, an assistant is typically needed, making it less practical for routine screening but essential for detailed surgical assessments.

Pederson and Graves: the North American pair

While UK practice overwhelmingly favours the Cusco, clinicians trained in North America may be familiar with the Pederson and Graves designs. The Pederson, with its narrow flat blades, works well for patients with a narrower canal. The Graves, with wider curved blades, provides maximum exposure for surgical procedures. Both operate on the same hinge-and-lock principle but differ in blade profile.

What speculum sizes are available?

Speculum sizing varies between manufacturers, but the following ranges are typical for Cusco-type bivalve speculums used in UK practice. The dimensions below are blade width (closed) and blade length.

Size	Blade Width (closed)	Blade Length	Typical Patient Profile
Virgin / Extra-Small	18 to 22 mm	70 to 75 mm	Adolescents, post-menopausal patients with significant vaginal atrophy, virginal examinations
Small	22 to 26 mm	65 to 75 mm	Nulliparous patients, slim build, early post-menopausal patients
Medium	25 to 30 mm	85 mm	Most adults. The standard starting size for routine examinations and cervical screening.
Medium Long	25 to 30 mm	100 mm	Same blade width as medium but longer reach. Useful for patients with higher BMI or a high cervix.
Large	28 to 32 mm	100 to 105 mm	Multiparous patients, patients with higher BMI, or where greater exposure is needed for surgical procedures.

A note on manufacturer variation: exact dimensions differ between brands. The Ultraspec medium, for example, has a slightly different blade profile to a standard Cusco medium. Always check the manufacturer's specification sheet if precise dimensions are critical for your ordering decision.

UK colour coding: which colour is which size?

Most UK disposable speculum manufacturers use colour-coded handles for quick size identification. While colours can vary slightly between brands, the following system is the most widely used:

Size	Typical Colour	Visual
Extra-Small / Virgin	White or Light Blue
Small	Blue
Medium	Green
Large	Yellow or Clear

Important: Colour coding is not standardised across all manufacturers. Always check the size printed on the handle or packaging rather than relying on colour alone when selecting a speculum.

How do you choose the right speculum size?

Selecting the correct speculum is a clinical judgment based on several patient factors. The general principle is to use the smallest instrument that provides adequate visualisation of the cervix. A speculum that is too large causes unnecessary discomfort; one that is too small may not hold the vaginal walls apart sufficiently, making the procedure more difficult and potentially requiring reinsertion with a larger size.

The key factors to consider are:

• Parity: Nulliparous patients (those who have not given birth vaginally) generally tolerate a small speculum better. Multiparous patients often require a medium or large.
• Age and hormonal status: Post-menopausal patients not on HRT may have vaginal atrophy, making a smaller speculum more appropriate. Younger patients may also need a smaller size.
• Body habitus: Patients with a higher BMI may require a longer-bladed speculum (medium long) to achieve adequate cervical visualisation.
• Procedure: A routine smear test may work with a small or medium, while a LLETZ or colposcopy typically requires a medium or large for full exposure.
• Cervical position: A retroverted uterus or a high cervix may require a longer blade. An anteriorly tilted cervix may be easier to visualise with a shorter instrument.
• Patient history and preference: Previous difficult examinations, anxiety, vaginismus, or female genital mutilation (FGM) all influence the choice. A conversation with the patient before the examination helps guide the decision.

Practical tip: Many experienced clinicians keep two sizes ready at the start of an examination, typically a small and a medium. If the initial choice does not provide adequate cervical visualisation, switching is straightforward with single-use instruments.

Insertion technique: clinical pearls

Proper speculum insertion technique is fundamental to a comfortable, successful examination. The following clinical pearls apply to Cusco-type bivalve speculums in routine use.

Before insertion

• Warm the speculum under warm running water for a few seconds. This simple step significantly improves patient comfort. Avoid microwaves or very hot water, as plastic speculums can warp.
• Apply lubricant sparingly to the outer surfaces of the blades. Use water-based lubricant only. Avoid the blade tips if you are taking a cervical sample, as lubricant can interfere with cytology results. Some screening protocols recommend warm water alone.
• Ask the patient to empty their bladder beforehand. A full bladder pushes the uterus posteriorly and increases discomfort.
• Explain the procedure. Tell the patient they will feel pressure but that they should speak up if they experience pain. Explain they will hear a click when the locking mechanism engages.

During insertion

• Hold the speculum in your dominant hand, hooking your index finger over the base of the upper blade for a secure grip.
• Insert with blades closed and oriented along the vaginal axis. Place the blade tips against the posterior vaginal wall, not the anterior wall, to avoid the urethra.
• Ask the patient to take a deep breath as you begin insertion. This helps relax the pelvic floor muscles.
• Apply gentle posterior pressure as you advance the speculum. Most of the pressure should be directed downward toward the perineum.
• Open the blades only as much as needed. Over-distension is unnecessary and painful. Just enough to visualise the cervix is sufficient.
• Apply uniform pressure along the entire lower blade. Pressing on the tip alone causes the base to pivot at the introitus, which can push the upper blade into the urethra.

During removal

• Keep the lower blade pressed against the posterior wall during withdrawal. This wall tolerates pressure better than the anterior wall.
• Partially open the blades during withdrawal to inspect the vaginal mucosa if a visual check is needed, but avoid full distension.
• Close the blades fully before withdrawing through the introitus.

What to do when the cervix is not visible

Failure to visualise the cervix on first attempt is common and does not indicate an error. The following adjustments usually resolve the issue without needing to change speculum size.

• Close the blades, withdraw slightly, and reinsert more deeply and posteriorly. The cervix is often higher and more posterior than expected.
• Let the base of the lower blade compress the perineum on reinsertion. This redirects the blade tips toward the posterior fornix where the cervix sits.
• If lateral vaginal walls collapse inward and obscure the view (common in multiparous and post-menopausal patients), consider a speculum with a sidewall retractor. The Ultraspec range includes one. Alternatively, a glove finger or condom placed over the speculum with the tip cut off can hold the walls back.
• If the cervix is anteriorly positioned, gentle downward pressure on the speculum handle may bring it into view.
• Size up only as a last resort. Adjust angle and depth first. Only switch to a larger speculum if the current one genuinely cannot provide adequate exposure after repositioning.

Disposable vs reusable speculums: which should your clinic use?

The shift from reusable metal speculums to single-use plastic devices has been one of the most significant changes in UK gynaecological practice over the past two decades. The majority of NHS trusts and GP surgeries now use disposable speculums as standard, and for good reason.

Why most UK clinics have moved to single-use

• Infection control: Single-use instruments eliminate the risk of cross-contamination entirely. There is no dependence on decontamination processes, autoclaving, or tracking instrument cycles.
• Cost efficiency: When you factor in the full cost of reprocessing (staff time, consumables, equipment maintenance, validation, and quality assurance), single-use speculums are often more cost-effective than their reusable counterparts.
• Consistent quality: Every disposable speculum is new. There are no worn hinge mechanisms, no corroded surfaces, and no blades that have lost their finish over repeated sterilisation cycles.
• Convenience: No waiting for instruments to come back from CSSD. Stock is always available and ready to use.

When reusable still makes sense

Stainless steel speculums remain relevant in a few specific scenarios. Some surgeons prefer metal instruments for operating theatre procedures where they need the rigidity and weight of steel. Metal Sims speculums, in particular, remain common in surgical settings. Reusable instruments may also be preferred in low-resource settings where supply chain reliability is a concern.

What speculum do you need for cervical screening?

Cervical screening (the NHS Cervical Screening Programme) is the single most common reason a speculum is used in UK primary care. The requirements are straightforward: full visualisation of the cervix so the sample taker can collect cells from the squamocolumnar junction using a cervical brush.

The recommended setup:

• Speculum type: Cusco (bivalve) with a locking mechanism. The self-retaining design frees both hands for sampling.
• Starting size: Medium for most patients. Have a small and a large available as backup.
• Material: Single-use plastic. This is the standard across NHS screening services.
• Lubricant: Water-based only, applied sparingly to the outer blades. Avoid lubricant on the blade tips where it may contaminate the cervical sample. Some screening protocols specify warm water alone.

For patients where lateral vaginal walls collapse inward and obscure the cervical view (common in multiparous and post-menopausal patients), a speculum with a sidewall retractor, or the condom-over-speculum technique, can help. The Ultraspec range includes an integrated sidewall retractor specifically designed for this purpose.

Warming the speculum: Running the speculum under warm water before insertion improves patient comfort significantly. This simple step takes seconds and is recommended in PHE cervical screening guidance. Avoid warming in a microwave or under very hot water, as plastic speculums can warp or become uncomfortably hot.

Frequently asked questions

What is the most commonly used speculum in the UK?

The Cusco (bivalve) speculum is the standard in UK clinical practice. Its self-retaining locking mechanism allows hands-free use, making it the preferred choice for cervical screening, IUD insertion, and routine gynaecological examinations. Most UK clinics stock disposable Cusco speculums in small, medium, and large sizes.

What size speculum should I use for a nulliparous patient?

A small Cusco speculum (approximately 22 to 26 mm blade width) is usually appropriate for nulliparous patients. If the patient is particularly anxious or has a very narrow introitus, an extra-small may be more comfortable. Always start with the smallest size likely to provide adequate cervical visualisation and size up only if needed.

Can you use lubricant with a speculum during cervical screening?

Yes, a small amount of water-based lubricant can be applied to the outer surfaces of the blades. Avoid applying lubricant to the blade tips, as this could contaminate the cervical sample. Some NHS cervical screening protocols recommend using warm water alone. Check your local screening service guidelines for specific advice.

What is the difference between a Cusco and a Graves speculum?

Both are bivalve (two-blade) speculums with a locking mechanism. The Cusco has slightly flatter, narrower blades and is the standard in UK practice. The Graves has wider, more curved blades that provide a larger opening, making it more common in North American surgical settings. For most UK clinical work, a Cusco in the appropriate size will meet your needs.

Are metal speculums still used in the NHS?

Metal (stainless steel) speculums are still used in some surgical settings, particularly Sims speculums for prolapse assessment and vaginal surgery. However, for routine examinations and cervical screening, single-use plastic speculums have become the standard across NHS trusts and GP practices due to superior infection control and cost efficiency when reprocessing costs are included.

How should I dispose of used speculums?

Single-use speculums should be disposed of in clinical waste bins (orange or yellow bags, depending on your local waste management protocol) immediately after use. They are classified as offensive or infectious clinical waste. Never attempt to reuse a single-use speculum, and never dispose of them in general waste bins.

What colour speculum is what size?

Most UK manufacturers colour-code speculum handles: light blue or white for extra-small, blue for small, green for medium, and yellow or clear for large. However, colour coding is not standardised across all brands, so always check the size printed on the handle or packaging before use.

What do you do if you cannot see the cervix?

First, close the blades and withdraw slightly, then reinsert more deeply and posteriorly, letting the lower blade compress the perineum. If lateral walls are collapsing inward, consider using a speculum with a sidewall retractor (such as the Ultraspec) or the condom-over-speculum technique. Only switch to a larger size after adjusting angle and depth.

Can a patient request a specific speculum size?

Yes. Patients have the right to discuss speculum size and express preferences. If a patient reports discomfort from previous examinations, starting with a smaller size is entirely appropriate. The clinician makes the final clinical decision, but patient communication and comfort should always be part of the process.

What is the difference between a medium and a medium long speculum?

Both have the same blade width (approximately 25 to 30 mm), but the medium long has blades around 100 mm rather than 85 mm. The extra length helps reach a high cervix, which is common in patients with higher BMI or when the uterus is retroverted. It provides better visualisation without increasing the width, so it is no more uncomfortable during insertion.

Do you need a different speculum for IUD fitting?

No, the same Cusco speculum used for cervical screening works for IUD and IUS insertion. A medium is usually sufficient, though the clinician may need a larger size if the cervix is difficult to visualise. The key requirement is that the locking mechanism holds the blades securely in the open position, as both hands are needed for device insertion.

How do you warm a plastic speculum safely?

Hold the speculum under warm (not hot) running water for 5 to 10 seconds. Shake off excess water before use. Do not use a microwave, autoclave, or hot water above approximately 50 degrees Celsius, as plastic speculums can warp or become uncomfortably hot. Warming improves patient comfort and is recommended in PHE cervical screening guidance.