Dr. Will Tanner working along a client's lower leg on a draped treatment table at Renu

Blood clots and prenatal massage: why we screen

Blood clots and prenatal massage: pregnancy and the six weeks after birth raise clot risk, so we screen your legs and never massage one with clot signs.

By The Renu lymphatic and massage team · 7 min read

Pregnancy and the six weeks after birth are a time of higher risk for a deep vein thrombosis, a clot in a leg vein, and the review of prenatal massage trials names it as the main safety concern: massaging a leg with an unrecognised clot can be life threatening. That is why every prenatal and postpartum session at Renu starts with a few questions about your legs. Throbbing pain in one leg, swelling in one leg, or red, blue or darkened skin around it means no leg work that day and an urgent call to your care provider; with breathlessness or chest pain it is an emergency. Ordinary pregnancy swelling, in both ankles by evening, is a different thing, and gentle lymphatic work for it is fine.

Of all the questions we ask before a prenatal massage, the ones about your legs are the ones we will never skip. This page explains why: what a clot is, why pregnancy makes one more likely, how the research on prenatal massage treats the risk, and how to tell the difference between the swelling almost everyone gets and the swelling that needs a doctor today.

Why pregnancy raises the risk of a clot

A deep vein thrombosis, or DVT, is a blood clot in a deep vein, usually in the leg. The NHS lists being pregnant, or having had a baby in the previous six weeks, among the circumstances that make a DVT more likely, alongside surgery, being confined to bed, long journeys and dehydration. The 2021 systematic review of prenatal massage trials puts the pregnancy figure at roughly five times the usual likelihood, and notes that pulmonary embolism, a clot that travels to the lungs, is the leading cause of maternal death in developed countries.

The review also explains why clots are easy to miss in pregnancy: the symptoms can look very much like the ordinary discomforts, swollen legs and back pain among them. A tired, puffy leg at 34 weeks is normal. A tired, puffy leg that is only on one side and hurts is a different thing, and the two can be hard to tell apart without asking the right questions.

What the research on massage says about clots

The review is unusually direct on this point. Among its precautions for massage in pregnancy, the first is the risk of thrombosis. It states that leg massage during pregnancy with an unrecognised DVT can be life threatening, and that no massage should be performed on the deep muscle tissue of the arms and especially the legs, to avoid loosening clots or causing haematomas. What it permits is specific: superficial lymphatic drainage and gentle stroking touches to alleviate oedema.

That single paragraph shapes how we approach leg work in pregnancy. The pressure on your calves and thighs is light and directional, closer to moving the skin than kneading the muscle, which is also the pressure used in lymphatic drainage massage. If you were hoping for a deep calf massage in pregnancy, this is the reason you will not get one from us, and we would rather explain it than quietly do less.

The questions we ask before any leg work

Before a prenatal or postpartum session reaches your legs, we ask:

Is the swelling in both legs, or one?
Did it come on gradually over days, or suddenly?
Is one calf or thigh painful, throbbing or tender to touch?
Is the skin anywhere on the leg warm, red, blue or darker than the rest?
Have you had a clot before, or been told you are at higher risk of one?
Have you recently been on a long journey, on bed rest, in hospital or had surgery?

Those questions come from the NHS description of DVT symptoms and risk factors, not from a form someone handed us. If the answers point one way, your legs are left alone that day and the appointment becomes a conversation about who to call.

Ordinary swelling versus a red flag

The contrast is clear once you know it.

Ordinary pregnancy swelling	Signs that need a doctor today
Both feet and ankles, roughly equal	Swelling in one leg
Builds through the day, worse in heat and after standing	Comes on over hours or a day or two, not tied to the clock
Eases overnight or with your feet up	Does not settle with rest or elevation
Tight, heavy, uncomfortable	Throbbing pain, usually in the calf or thigh
Skin looks normal	Skin red, blue or darkened around the painful area
No other symptoms	Breathlessness or chest pain alongside the leg symptoms

The left column is the common story, covered on swollen feet and ankles in pregnancy, and light lymphatic work helps it. The right column is the NHS description of a DVT, and the advice is to ask for an urgent GP appointment or call an urgent care line the same day. If the leg symptoms come with difficulty breathing or chest pain, the NHS says to call emergency services, because that combination can mean a clot has reached the lungs. ACOG’s own warning list for pregnancy includes calf pain or swelling as a reason to stop and call your obstetric provider.

Swelling that is only in one leg is a question we hear outside pregnancy too; why one leg is more swollen than the other covers the wider list of causes.

After birth, and especially after a caesarean

The risk does not end at delivery. The NHS counts the six weeks after birth as a time of higher DVT risk, and a woman treated for a clot in pregnancy usually continues blood-thinning injections until her baby is six weeks old. Caesarean birth adds surgery to the list. ACOG names blood clots in the legs, pelvic organs or lungs among the risks of caesarean delivery, and describes the precautions taken in theatre: massaging sleeves around the legs that fill with air to keep blood moving, and clot-preventing medication for women with extra risk factors.

The NHS recovery advice after a caesarean lists the signs to report to your midwife or GP straight away, and two are about clots: swelling or pain in your lower leg, and a cough or shortness of breath. ACOG’s list of reasons to call your obstetrician right away after a caesarean includes leg pain and shortness of breath.

So our screening questions carry on through the postpartum weeks. A massage after birth begins with the same leg check as a prenatal one, and leg work stays superficial until the six-week mark has passed and your legs are symptom-free.

What happens instead, if we are worried

If something in your answers or on your leg concerns us, this is what the appointment turns into:

No leg work. We do not test the leg by massaging it, and we do not try to move the swelling along. Nothing on the leg is touched.
A call, with you. The NHS pathway is an urgent appointment with your GP or midwife, or an urgent care line, the same day. We will help you find the number and make the call from the clinic if that is easier.
Emergency services if you are breathless or have chest pain. Not a drive to the clinic’s nearest walk-in; an ambulance.
The rest can wait. If you are well apart from the leg, we may still offer neck, shoulder and hand work, or simply reschedule. Either way, the time spent sorting that out is part of looking after you, not an inconvenience.

This is not about covering ourselves. Treating a leg that should have been scanned is the one mistake in prenatal massage that cannot be undone, and the review says as much. Asking five questions costs two minutes.

Lowering your risk between sessions

The NHS prevention advice for DVT is ordinary and worth repeating: stay active, drink plenty of fluids, avoid long periods of sitting still, do not smoke, and wear loose clothing on long journeys. The foot and ankle movements we suggest for everyday swelling do double duty here, because the calf muscles are the pump that keeps blood moving up the leg. If you have been told you are at higher risk, or have had a clot before, mention it at booking; it changes how we work and it should also be part of your conversation with your care provider.

If your legs are symptom-free and simply tired, book a prenatal massage and expect the light, directional leg work described here. If one leg is painful, swollen or discoloured, close this page and call your care provider first. We will be here afterwards.

Questions people ask

Can a massage dislodge a blood clot?

The prenatal massage review treats that as a real risk: it advises against deep muscle massage of the arms and especially the legs in pregnancy, to avoid loosening clots or causing bruising, and says leg massage with an unrecognised DVT can be life threatening. That is the reason for our screening questions and for the light, superficial leg work we use in pregnancy.

How do I tell pregnancy swelling from a clot?

Ordinary pregnancy swelling affects both feet and ankles, builds through the day and eases overnight. The NHS describes a DVT as throbbing pain in one leg, rarely both, usually in the calf or thigh, swelling in one leg, and red, blue or darkened skin around the painful area. One-sided, painful, warm or discoloured is the pattern that needs a doctor the same day.

I had a caesarean two weeks ago. Can I have my legs massaged?

Only after screening, and only lightly. ACOG lists blood clots in the legs, pelvis or lungs among the risks of caesarean birth, and the NHS tells women to contact their midwife or GP straight away for swelling or pain in the lower leg, or a cough or shortness of breath, after a caesarean. The six-week window of higher clot risk after any birth applies, so if your legs are symptom-free we keep to gentle, superficial work.

What happens if you suspect a clot during my appointment?

We stop leg work, we do not try to rub it out, and we help you make the call: an urgent appointment with your GP, midwife or an urgent care line the same day, or emergency services if you are also short of breath or have chest pain. The rest of the massage can wait; a clot cannot.