Round ligament pain is a sharp, pulling pain low in the abdomen or groin, usually on one side, caused by the ligaments supporting the uterus being stretched as pregnancy grows. Episodes typically last only seconds, are triggered by movement such as rolling over, standing up or coughing, and ease when you stay still. It is harmless in itself, but pain that is constant, worsening, or comes with bleeding, fever, vomiting or regular tightenings is not round ligament pain and needs same-day assessment.
The pain that brings most women to this page arrives without warning: a catch low down on one side as you turn over in bed, rise out of a low chair, or sneeze, sharp enough to stop you mid-step or to wake you at three in the morning. Most of the time the explanation is purely mechanical and completely benign, and the ligaments either side of the uterus are simply being asked to lengthen faster than they are comfortable doing. What makes it worth reading about properly rather than shrugging off is that one-sided pain low in the abdomen is also how several problems that genuinely need attention announce themselves in pregnancy, and what separates them is the pattern of the pain rather than how badly it hurts.
So the useful skill is not treating the pain but sorting it. On this page I set out what the round ligaments are and why they hurt, exactly where the pain is felt and where it is not, when in pregnancy it tends to appear, what sets off an episode, what genuinely reduces how often it happens, which stretches are safe, how it differs from appendicitis, an ectopic pregnancy, labour and a urinary infection, and the specific features that mean you should be seen the same day rather than waiting it out.
What Round Ligament Pain Actually Is
Round ligament pain comes from two cord-like ligaments, one on each side, that run from the upper outer corners of the uterus, forward and down through the groin, and end in the soft tissue of the labia and pubic mound. Each one is only a few millimetres thick when you are not pregnant. They contain smooth muscle fibres, connective tissue, blood vessels and small nerves, which is precisely why they can hurt: a ligament with muscle in it can spasm, and a ligament with nerves in it can report that spasm as pain.
In pregnancy two things happen to these ligaments at once. First, the uterus grows from roughly the size of a pear to something that fills the abdomen, and the round ligaments have to lengthen and thin out to follow it. Second, the hormonal environment of pregnancy, including progesterone and relaxin, softens connective tissue throughout the body. A longer, softer, more heavily stretched ligament behaves less like a tendon and more like an elastic band pulled near its limit. When it is loaded suddenly it contracts or snaps taut, and that is the moment you feel.
Blood flow through these ligaments also increases substantially in pregnancy, and the veins within them enlarge. That extra bulk and weight contributes to the dragging, heavy sensation that many women describe in between the sharp episodes.
Why it is usually on one side
Most women feel it on the right more often than the left. The uterus naturally rotates slightly to the right in most pregnancies, which puts marginally more tension on the right round ligament. This is normal anatomy, not a sign that something is wrong on that side. Equally, left-sided or alternating pain is entirely ordinary, and some women feel both sides in the same day.
What Round Ligament Pain Feels Like
The classic description is a sharp, stabbing or pulling pain that arrives suddenly, peaks almost immediately, and fades within a few seconds. Many women compare it to a muscle being pulled, a stitch, or a brief jab or spasm. It is often severe enough to stop you walking or make you catch your breath, and then it is simply gone.
After the sharp episode, a duller, achy or bruised feeling may linger over the same spot for several minutes, sometimes an hour or two. That residual ache is part of the same picture. What should not happen is a pain that builds steadily over hours and keeps getting worse.
Several variations are worth naming, because women often worry that their version is not the textbook one:
- A pulling or stretching sensation rather than a stab, particularly when you change position slowly.
- A brief burning or electric quality running along the line from hip to groin.
- Pain that radiates down into the labia or the upper inner thigh on the affected side.
- A tender patch you can put a finger on afterwards, uncomfortable to press but not hot or rigid.
- Several episodes clustering in one busy day, then nothing for a week.
Does it feel like period cramps?
Usually not, and this is a useful distinction. Period-type cramping is midline, low, deep and wave-like, felt across the lower abdomen. Round ligament pain is lateral, sharper, briefer and tied to movement. If what you are feeling is rhythmic central cramping that comes and goes in waves, that is a different symptom and deserves a different conversation, particularly if it is becoming regular.
Where You Feel Round Ligament Pain
Round ligament pain is felt along a line, not at a single point. The typical location is the lower abdomen on one side, roughly between the level of the hip bone and the pubic bone, and the pain often runs diagonally downwards and inwards towards the groin crease. If you trace a line from the outer edge of your bump, just inside the bony prominence at the front of the hip, down to the pubic area, you are following the course of the round ligament.
From there the pain may be referred further: into the groin itself, into the labia on that side, or into the top of the inner thigh. Referred pain in the labia surprises many women but is anatomically expected, because that is where the ligament ends.
Where round ligament pain is not felt
This is as important as where it is felt. Round ligament pain is not a flank or back pain, it is not felt around the navel, it is not under the ribs, and it is not high in the abdomen. Pain in those areas during pregnancy has other explanations and should be assessed on its own merits. Loin pain that wraps from the back round towards the front suggests the urinary tract. Pain under the right ribs or high in the abdomen in the second half of pregnancy is specifically a symptom that needs same-day attention, because of its association with blood pressure disorders of pregnancy.
The pain also does not involve the whole uterus. If the entire bump is tightening and releasing, or if it feels hard and tender all over, that is a uterine symptom rather than a ligament one, and it is assessed differently.
When Round Ligament Pain Starts, and Why Pregnancy Causes It
Most women first notice round ligament pain in the second trimester, commonly between about 14 and 24 weeks. That timing is not arbitrary. It is the period when the uterus is growing fastest relative to its original size and is rising out of the pelvis into the abdomen, so the ligaments are being stretched at the greatest rate.
It can start earlier. Some women feel it towards the end of the first trimester, from around 10 to 12 weeks, particularly in a second or subsequent pregnancy, in a twin pregnancy, or where the uterus was already enlarged by fibroids. It can also continue right through the third trimester, where it tends to feel more like a dragging pull with occasional sharp catches rather than the clean stabs of mid-pregnancy.
Pain in early pregnancy needs more caution
New one-sided pain before about 10 weeks is not well explained by ligament stretch, because the uterus has barely grown at that stage. It needs assessment first rather than reassurance, and the features that matter are set out in the section on ectopic pregnancy below.
Is round ligament pain a good sign?
It is a normal sign, which is not quite the same thing. It tells you the uterus is growing and the ligaments are adapting to it. It does not measure how well the pregnancy is progressing, and its absence means nothing bad either. Plenty of women go through an entirely healthy pregnancy without a single episode. Nor does the severity of an episode say anything about the pregnancy: a very painful catch and a mild pull carry the same meaning.
What Triggers It: Sudden Movement, Coughing, Rolling Over
The trigger is almost always a sudden change in load on the ligament. Anything that abruptly shortens or lengthens it, or abruptly raises the pressure inside the abdomen, can set it off. In practice the common triggers are:
- Rolling over in bed, or sitting up out of bed quickly. This is the most frequently reported trigger of all, and the reason so many women are woken by it.
- Standing up from sitting, especially out of a low or soft chair.
- Coughing, sneezing, laughing or vomiting, all of which raise abdominal pressure sharply.
- Twisting at the waist, reaching upwards, or bending sideways to pick something up.
- Walking briskly, climbing stairs, or a longer or faster walk than you are used to.
- Exercise, particularly movements that load the hip flexors or involve rapid changes of direction.
- A full day on your feet, where the discomfort tends to build towards the evening.
- Straining with constipation, which is itself common in pregnancy.
- Sexual intercourse or orgasm, which involve pelvic muscle contraction.
Recognising your own trigger is genuinely useful, because almost every item on that list can be modified. The pain is mechanical in origin, so mechanical adjustments are what work. It is worth noticing the pattern over a few days: for most women one or two triggers account for the large majority of their episodes, and those are the ones to work on first.
Does It Come and Go, or Can It Be Constant?
Round ligament pain is intermittent and positional by its nature. It comes in brief episodes provoked by movement, with a possible dull aftertaste, and it is absent or minimal when you are still. A background ache for a few hours after a heavy day is within the normal range, and so is a stretch of several days where it keeps recurring before it quietens down again.
What is not typical is genuinely constant pain. Pain that is constant for more than two hours, that has not eased with rest and a change of position, that is getting worse rather than better, or that is keeping you awake through the night should not be filed under round ligament pain. Constant, progressive, one-sided pain is the pattern of appendicitis, of a twisted ovarian cyst, and of several other problems that need examination. Two hours is a deliberately short threshold. Nothing dangerous happens at the two-hour mark; it is simply early enough to catch the conditions that matter while they are still straightforward to treat.
The pattern is more informative than the intensity. A very painful ten-second stab is reassuring. A moderate pain that has not stopped since this morning is not. Pain severe enough to make you vomit, pain with a fever, and pain for which you cannot find any position of relief all belong in the second category. Severity alone does not take round ligament pain off the list, but duration and progression do.
How to Tell It Apart From Appendicitis, Ectopic Pregnancy, Labour or a UTI
This is the section most women are actually looking for. Three questions do most of the work: how long has the pain lasted, is it getting worse, and what else is happening alongside it.
Appendicitis
Appendicitis is the commonest non-obstetric surgical emergency in pregnancy and the most important mimic. Its pattern is different in ways you can usually recognise. It typically begins as a vague, central, around-the-navel discomfort and then migrates to settle in one spot on the right over several hours. In pregnancy the appendix is pushed upwards and outwards by the growing uterus, so that spot may be higher than the classic position. The pain is constant and worsening rather than episodic. Appetite disappears early, nausea and often vomiting follow the pain rather than preceding it, and there may be a low-grade fever. The most useful distinction from ligament pain is that lying still brings no relief at all: with a stretched ligament, stillness settles it within seconds.
Ectopic pregnancy
This is a first-trimester concern, and it is the reason I do not reach for the ligament explanation early on. Before about 10 weeks the uterus has barely grown, so ligament stretch is an unconvincing account of new one-sided pain. An ectopic pregnancy typically declares itself between about six and ten weeks with one-sided lower abdominal pain, often with light vaginal bleeding or brown discharge, and the pain tends to be persistent rather than fleeting. The warning features are shoulder-tip pain, feeling faint or dizzy, pain on opening the bowels, and pain that is escalating. Because the early signs of an ectopic pregnancy overlap so closely in site with ligament pain, new unilateral pain in the first trimester earns a scan rather than reassurance. Mild, brief, movement-related twinges in a pregnancy already confirmed on scan to be inside the uterus are a different matter, but the scan comes first.
Labour, preterm labour and Braxton Hicks
Labour pain is uterine, not ligamentous. It involves the whole bump tightening, it comes at intervals that become shorter, stronger and more regular, it is usually felt low and centrally with pressure in the back and pelvis, and it does not stop when you lie down. It may come with a mucus or bloody show, or with fluid leaking. Braxton Hicks tightenings also involve the whole uterus but are irregular, do not intensify in a pattern, and are generally uncomfortable rather than painful. Round ligament pain, by contrast, is a one-sided catch with no tightening at all. Any regular tightenings before 37 weeks need assessing urgently.
Urinary tract infection
A urinary infection produces midline pain low down, over the bladder, not a diagonal line towards the groin. The giveaways are burning or stinging when you pass urine, needing to go far more often than usual, sudden urgency, and cloudy or strong-smelling urine. If the infection has reached the kidney you would expect pain in the flank or back, fever with shivering, and vomiting, and that needs same-day treatment. It is worth knowing how to go about telling a urinary infection apart from a vaginal infection, since the two are frequently confused. Urinary infections in pregnancy are treated rather than watched, because of the association with preterm labour, so a urine sample is a low-effort way to settle the question.
Ovarian problems and kidney stones
A cyst that twists or bleeds causes sudden, severe, constant one-sided pain, often with vomiting, and it does not ease with position; if you already know you have a cyst, it is worth being familiar with the ovarian cyst symptoms that warrant urgent review. A kidney stone causes a severe gripping pain that travels from the loin round to the groin in waves, often with blood in the urine, and tends to leave a woman restless and unable to settle anywhere. Both need imaging rather than reassurance.
Musculoskeletal pain of pregnancy
Pelvic girdle pain is the other common and benign cause, and it is frequently mislabelled as round ligament pain. It is felt over the pubic bone at the front or over the dimples at the base of the spine at the back, it is provoked by walking, stairs, turning in bed and standing on one leg, and it tends to be a grinding or clicking discomfort rather than a stab. Assessment by a physiotherapist experienced in pregnancy is the usual route for it. An abdominal wall muscle strain, or a small hernia in the groin, can also mimic ligament pain, and both are identified on examination.
What Actually Helps: Positioning, Support, Movement and Warmth
No treatment stops the ligaments stretching, because that stretching is normal and necessary. What works is reducing the sudden loads that provoke spasm, supporting the weight pulling on the ligament, and calming the muscle once it has gone into spasm. These measures make a real difference to how often the pain happens.
In the moment
When the pain strikes, stop and flex. Bending forwards towards the side that hurts, or drawing your knees up towards your chest if you are lying down, shortens the ligament and takes the tension off it. Most episodes ease within seconds of doing this. Placing a flat hand over the painful area and pressing gently does the same thing. Breathing out slowly rather than holding your breath helps too, because breath-holding raises abdominal pressure.
Changing how you move
Get out of bed by rolling onto your side first, drawing your knees up, then pushing up with your arms, rather than sitting straight up through your abdomen. Turn in bed as one unit, knees together, rather than twisting your pelvis against your shoulders. Brace before you cough or sneeze by flexing your hips slightly, bending forward a little and supporting the lower abdomen with your hand; that single adjustment can prevent many episodes. Stand up from a chair by moving to the edge of the seat and rising through your legs. In general, slow the transitions down: the speed of a movement matters more than the movement itself.
Support and positioning
A maternity support belt or belly band takes some of the weight of the uterus off the ligaments. It is most useful from the middle of the second trimester onwards, and on days involving a lot of standing or walking. It should sit low, under the bump, and feel supportive rather than tight. For sleep, lying on your side with a pillow between your knees and another supporting the underside of the bump keeps the pelvis neutral and prevents the overnight pull that wakes so many women. A full-length pregnancy pillow does the same job.
Warmth, pacing and bowels
Warmth relaxes ligament spasm well. A warm compress or wheat bag over the painful area, or a warm bath, both help. Keep the water comfortably warm rather than hot, and avoid very hot baths, saunas and hot tubs in pregnancy. Rest matters on days when the pain has been frequent, and breaking up a long day with sitting breaks reduces the evening build-up. Treating constipation with fluids, fibre and gentle movement removes one of the commonest triggers.
Pain relief
If simple measures are not enough, paracetamol is the analgesic usually considered first in pregnancy, and you should check with your own doctor or midwife before taking any medication, including anything bought over the counter. Anti-inflammatory painkillers of the ibuprofen class are generally avoided in pregnancy, particularly in the second half, and should only be taken if a doctor has specifically advised them for you. I do not prescribe or adjust medication for anyone I have not assessed in person, and neither should a web page.
Stretches and Exercises That Are Safe in Pregnancy
Gentle, regular movement helps more than rest alone, because it keeps the hip and abdominal muscles that share the load working properly. The aim is slow, controlled, pain-free movement. Nothing below should hurt while you do it; if a movement reproduces the sharp pain, stop that movement.
- Pelvic tilts. On your hands and knees, or standing with your back against a wall, gently tip your pelvis so the low back flattens, hold a few seconds, then release. Repeat slowly a handful of times. This mobilises the pelvis without loading the ligament.
- Cat and camel. On hands and knees, arch the back gently upwards, then let it return to neutral. Avoid dropping into a deep sag, which increases the pull on the front of the abdomen.
- Side-lying knee hug. Lying on the side that does not hurt, with a pillow supporting the bump, draw the upper knee, which is the one on the painful side, slowly towards your chest and hold for a slow count of ten. This shortens the ligament on the painful side and is useful last thing at night.
- Standing hip flexor stretch. With one foot forward in a short stride and both feet facing forwards, shift your weight gently forward until you feel a mild stretch at the front of the back hip. Hold briefly, keeping the pelvis level, and keep it mild.
- Supported sit-to-stand. Holding a worktop, lower a short way and come back up, feet flat and knees apart. This trains the leg strength that lets you stop rising through your abdomen.
- Pelvic floor and deep abdominal activation. Draw the pelvic floor up gently as you breathe out, and feel the lower abdomen flatten slightly. Done regularly, this improves the natural bracing that protects the ligaments during a cough or a sudden movement.
- Swimming and water-based exercise. Being supported by water removes the downward pull entirely, which is why many women find it the most comfortable exercise of the second half of pregnancy.
What to avoid
Avoid sudden twisting, deep abdominal rotation, heavy lifting, crunch-type abdominal exercises, and anything involving rapid changes of direction. Prenatal yoga or Pilates taught by someone trained in pregnancy is a reasonable route, provided you tell the instructor about the pain and where you feel it. If the pain is frequent, persistent, or limiting what you can do day to day, a referral to a physiotherapist specialising in pelvic health is worthwhile, and it is a straightforward thing to arrange at a routine appointment.
Red Flags: When Pain Is Not Round Ligament Pain
Round ligament pain should be brief, movement-related, one-sided, and unaccompanied by anything else. The features below mean the pain should be assessed the same day, and in several cases immediately. This list is deliberately low-threshold, and I would far rather review a woman who turns out to have nothing more than a stretched ligament.
- Pain that is constant for more than two hours, or that is steadily worsening.
- Any vaginal bleeding during pregnancy, or fluid leaking from the vagina.
- Fever, shivering, or feeling generally unwell alongside the pain.
- Vomiting with the pain, or pain severe enough to cause vomiting.
- Burning when passing urine, needing to pass urine very frequently, or pain in the flank or back.
- Regular tightenings of the whole bump, or pelvic pressure, before 37 weeks.
- Reduced or absent fetal movements compared with your own normal pattern.
- Dizziness, feeling faint, a racing heart, or shoulder-tip pain.
- Pain in the upper abdomen or under the ribs, particularly with headache, visual disturbance, or new swelling of the face and hands, which are warning signs of preeclampsia.
- A bump that feels hard, rigid or tender all over.
- Pain after a fall, a road accident, or any blow to the abdomen.
- Pain not relieved at all by resting and changing position.
If you are unsure, the default is to contact your maternity unit or your own doctor rather than to wait and watch. The assessment is usually quick: an abdominal examination, a urine test, your blood pressure, listening to the baby, and an ultrasound scan where needed. Together those usually separate the benign from the urgent, often in a single visit, and knowing which one you are dealing with is worth the trip.
How Long Round Ligament Pain Lasts
Each individual episode lasts seconds, with any after-ache fading over minutes to an hour or two. The phase of pregnancy in which the pain keeps recurring usually spans several weeks to a few months. For most women it is at its most noticeable through the middle of pregnancy and becomes less sharp later on, although a dragging version can persist until birth.
It resolves after delivery. The ligaments are no longer being stretched once the uterus begins to shrink back, so the pain typically settles within days of birth, and sometimes immediately. There is nothing to repair and no lasting damage. Having had it in one pregnancy does not commit you to having it in the next, although women who have had it once tend to recognise it much earlier the second time.
If sharp one-sided groin pain continues for weeks after birth, that is no longer round ligament pain and deserves a separate look. Causes after delivery include a groin hernia, irritation of a nerve in the abdominal wall, and pelvic girdle pain that has not resolved on its own. None of these needs to be tolerated indefinitely, and all are assessable at a postnatal appointment, so it is worth raising rather than waiting for it to fade.
Round Ligament Pain When You Are Not Pregnant
This is a common search, and the honest answer is that outside pregnancy the round ligament is an uncommon source of pain, so the label usually belongs to something else. The ligament is thin and barely loaded when the uterus is its normal size, which means one-sided groin pain in a woman who is not pregnant deserves a proper diagnosis rather than that name.
Conditions that produce pain in the same place include ovulation pain in mid-cycle, an ovarian cyst, endometriosis, which can genuinely involve the round ligament itself and cause cyclical groin pain, a small inguinal hernia, irritation of the ilioinguinal or iliohypogastric nerves after previous abdominal or pelvic surgery, hip joint problems, and simple musculoskeletal strain. Scar tissue from an earlier caesarean or laparoscopy can also tether tissue in that area and pull on it.
The pattern is what directs the diagnosis. Pain tied to the menstrual cycle points one way; pain that appears on coughing or lifting and comes with a lump in the groin points towards a hernia; pain that changes with hip position points towards the joint. An examination with an ultrasound scan where appropriate usually clarifies it. Persistent one-sided pelvic pain in women is worth investigating properly rather than living with, and it is a very common reason for a gynaecology appointment.
References
The following current and independent health sources were used in preparing this article.
- NHS. Pregnancy
- MedlinePlus. Pregnancy
- American College of Obstetricians and Gynecologists (ACOG). Women's Health
- Royal College of Obstetricians and Gynaecologists (RCOG). Information for the Public
