MVA Cannula Sizes Explained: How Cannula Diameter Is Selected and What the Kit Includes
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MVA cannulas are sized by their outer diameter in millimeters, and the clinician chooses a diameter based mainly on uterine size and gestational age, along with cervical findings and their training. Our IPAS-style MVA kit includes eight sterile Karman cannulas (4, 5, 6, 7, 8, 9, 10 and 12 mm) so a full range is on hand for each procedure. This post explains how cannula sizing works, what affects the choice, and exactly what is in the kit.
For background on the procedure itself, see Manual Vacuum Aspiration: What It Is & How It Works. If you are comparing suppliers, our IPAS MVA kit alternatives comparison covers that. Here we stay focused on cannulas.
What an MVA cannula is
A cannula is the thin tube that passes through the cervix into the uterus. It attaches to the hand-held MVA syringe, which creates the vacuum. When the syringe valve is released, suction draws tissue through the cannula's openings and into the syringe.
The cannulas in our kit are Karman-type cannulas. According to the product listing, they have:
- A smooth, rounded tip
- Lateral atraumatic eyes (side openings) for smooth uterine cavity access
- Medical-grade polypropylene construction
- Individual sterile packaging in a peelable pouch
- Single-use per patient design
How cannula sizes are named
The number on a cannula refers to its outer diameter in millimeters. A 6 mm cannula is 6 mm across; a 10 mm cannula is 10 mm across. Larger diameters move tissue more efficiently but need more cervical dilation to pass. Smaller diameters pass more easily but take longer to evacuate a larger uterus.
That trade-off is the heart of cannula selection: the clinician is balancing ease of insertion against efficient, complete evacuation.
How the cannula diameter is selected
Cannula choice is a clinical decision. It should follow the clinician's training, the manufacturer's instructions for use (IFU), facility protocols and recognized guidance such as WHO and Ipas clinical resources. In general terms, clinicians consider:
Uterine size and gestational age
The product listing describes the widely taught convention that cannula size in millimeters typically matches gestational age in weeks; for example, a 5 mm cannula around 5 weeks or an 8 mm cannula around 8 weeks. This is a general starting point, not a fixed rule. Uterine size on examination matters as much as dates.
The cervix
How open the cervix is, and how easily it dilates, affects which cannula can pass comfortably. In cases such as incomplete miscarriage the cervix may already be partly open, while in other situations dilation is needed first. Cervical preparation and dilation decisions belong to the clinician.
The clinical situation
The indication (for example, incomplete miscarriage management, post-abortion care, or endometrial sampling) and the patient's individual history all shape the choice. Some clinicians may select a smaller or larger cannula than the "weeks equals millimeters" convention suggests, based on what they find.
Why a full range matters
Gestational dating is not always exact, and examination findings can differ from what was expected. As the listing notes, having all sizes in one kit means there is no need to reorder mid-procedure if dating was off. A clinician can step up or down a size from the same kit.
The kit's cannula range at a glance
| Cannula (mm) | General convention from product listing |
|---|---|
| 4 mm | Smallest size in kit |
| 5 mm | Around 5 weeks (example given in listing) |
| 6 mm | Around 6 weeks |
| 7 mm | Around 7 weeks |
| 8 mm | Around 8 weeks (example given in listing) |
| 9 mm | Around 9 weeks |
| 10 mm | Around 10 weeks |
| 12 mm | Largest size in kit; upper end of first-trimester range |
The listing describes the kit for first-trimester procedures at 5–12 weeks of gestation. The table shows a general convention only; final selection always rests with the treating clinician.
What is in the SciMed MVA kit
According to the product listing, each kit contains:
- 1 × double-valve MTP syringe (60 mL), IPAS-style
- 8 × Karman cannulas (4, 5, 6, 7, 8, 9, 10, 12 mm), each individually sterile-packed
- 1 × set of adapter connectors
- 1 × silicone lubricating oil
- Sterile peelable pouch packaging for each cannula
- Outer carton with lot and expiry markings
Key specifications from the listing: vacuum up to 24 inHg (~610 mmHg), kit weight about 180 g, and IPAS MTP double-valve design. The listing states the syringe and cannulas follow the IPAS MTP double-valve design standard used by IPAS-trained providers.
Adapters and connections
The adapter connectors let each cannula size attach securely to the syringe. Before each case, staff typically confirm that the chosen cannula seats firmly with the right adapter, as described in the IFU.
The silicone lubricating oil
The included silicone oil is for the syringe, helping the plunger move smoothly and keeping the seal working well. Follow the IFU for how and when to apply it.
Single-use cannulas, reprocessable syringe
This is an important distinction for stock planning:
- Cannulas are single-use per patient and must be discarded after one procedure.
- The syringe is autoclavable and reprocessable per IPAS reprocessing protocols, according to the listing.
Because only one cannula is usually used per procedure, clinics often find that certain sizes run out faster than others. It is worth tracking which sizes you use most so you can keep enough sterile stock on the shelf.
Practical tips for storing and managing cannulas
- Store cannulas in their sealed pouches in a clean, dry place, organized by size.
- Check each pouch for damage and the expiry date before opening.
- Open only the size you intend to use, at the point of use.
- Keep the full size range available in every procedure room.
- Rotate stock so older lots are used first.
Our MVA procedure guide and clinical standards post covers broader room setup and equipment checks.
Ordering for a hospital, women's health program or humanitarian NGO? Email sales@scimedstore.com or WhatsApp +1-669-265-9353 for institutional pricing.
Frequently asked questions
What cannula sizes come in the SciMed MVA kit?
Eight Karman cannulas: 4, 5, 6, 7, 8, 9, 10 and 12 mm. Each one is individually sterile-packed in a peelable pouch.
Does cannula size always match weeks of gestation?
Not always. Matching millimeters to weeks is a common general convention, but the clinician also considers uterine size on examination, the cervix and the clinical situation. Selection should follow clinical training, the IFU and recognized guidance.
Can MVA cannulas be reused?
No. The cannulas are single-use per patient and must be discarded after one procedure. The double-valve syringe is autoclavable and reprocessable per IPAS reprocessing protocols.
Are the cannulas compatible with IPAS-style syringes?
The product listing states the syringe and cannulas follow the IPAS MTP double-valve design standard, and the kit includes a set of adapter connectors for attaching each cannula size.
What are the cannulas made of?
Medical-grade polypropylene, with a smooth rounded tip and lateral atraumatic eyes for smooth uterine cavity access.