Part of Pregnancy back and pelvic pain

Lightning crotch, round ligament pain or pelvic girdle pain?

Lightning crotch is the word women use for a sudden, stabbing pain low in the pelvis, in the vagina or deep in the crotch, that arrives in a second and is gone again. The names come second, because no word for this pain separates a stretching ligament from the signs that need a phone call. If you are less than 37 weeks pregnant and the pain comes with regular tightenings, period-type pains, backache that is not usual for you, or a gush or trickle of fluid, the NHS puts all four on its list for premature labor and asks you to call your midwife or maternity unit. Bleeding, your waters breaking, a change in your baby's movements, a severe headache or sudden vision changes go the same way, at any week. Sharp pelvic pain on its own, with none of that, usually comes from the structures being stretched and loaded, and three names get used for it. Round ligament pain has the clearest story behind it: the round ligaments run from the upper corners of the womb, through the groin, and end in the labia, and the NHS describes the pain of them stretching as a sharp cramp on one side of your lower tummy. Pelvic girdle pain is pain in the pelvic joints, and it is provoked by walking, stairs, standing on one leg and turning over in bed rather than arriving out of nowhere. Lightning crotch is not a medical term. No source we could read defines it, so nobody, this page included, can tell you from a description which of those two is behind yours, or whether it is either one. What we can do is set out what each one usually feels like and where, and say plainly that a sharp pelvic pain which keeps coming, which lasts, or which arrives with any of the signs above belongs to the people looking after your pregnancy.

Warning signs, and when to get help

What is lightning crotch?

Lightning crotch is a patient's word, not a clinician's. It describes a sudden, stabbing pain low in the pelvis, often in the vagina or deep in the crotch, that lands in a second and has gone before you can take a breath. We searched for a clinical definition and did not find one, so treat it as a description of a sensation and nothing more. Nobody can turn that description into a diagnosis, however confidently it has been explained to you.

So start with the phone call rather than with the name. Go to the warning signs at the foot of this page first, and read them against what has actually been happening to you. If you are less than 37 weeks pregnant and there have been tightenings, period-type pains, unusual backache or any fluid, that list is where the answer is, and pelvic girdle pain or contractions goes through the same question in more detail.

A word on who this is for. It is written for women who are pregnant, and it is not the right page if you are using the phrase outside pregnancy or after the birth. Sharp pelvic pain has gynecological, urinary and bowel causes that have nothing to do with a growing womb, and those need a doctor's assessment rather than an explanation borrowed from pregnancy.

What round ligament pain feels like, and where

Of the three names, this is the one with a clear structure behind it. Each round ligament is a band roughly 10 to 12 cm long that starts at the upper outer corner of the womb, leaves the pelvis through the deep inguinal ring, runs along the inguinal canal in the groin, and ends in several strands in the labia (Yeo 2021). It carries veins, arteries, lymphatics and nerves, which is worth knowing when you are wondering how a ligament can hurt that sharply.

The NHS groups the pain of those ligaments stretching with the ordinary pains of pregnancy and calls it a sharp cramp on one side of your lower tummy, sometimes called growing pains as the ligaments stretch to support your growing bump. Its test for the ordinary kind is behavioral rather than anatomical: mild pain that eases when you change position, rest, open your bowels or pass wind. One side is the usual pattern, and the side varies between women.

One thing about that area does not get said often enough. A new lump or swelling in the groin during pregnancy is not round ligament pain and is not something to explain away. It needs examining, because swollen veins alongside the round ligament look and feel much like a hernia and are told apart with an ultrasound scan rather than by touch (Yeo 2021).

Tell your midwife or doctor about a groin lump, especially one that changes size when you cough or stand. If it becomes painful, hard or red, if you cannot push it back in, or if it comes with a bloated tummy, feeling or being sick, constipation or a high temperature, that is the same day rather than the next appointment, because a hernia there can become trapped. Severe or sudden pain in the lump, not being able to poo or pass wind at all, vomiting blood, or sudden confusion is emergency services, and do not try to push the lump back in yourself. Pregnancy makes that one harder to read than it sounds, because feeling sick and being constipated are so ordinary in pregnancy that they are easy to put down to the pregnancy itself.

How lightning crotch differs from pelvic girdle pain

Pelvic girdle pain is a different animal, and the European guideline is specific about where it sits: pain between the back of the pelvic rim and the buttock crease, particularly around the joints where the pelvis meets the base of the spine (the sacroiliac joints), which may radiate into the back of the thigh and may also be felt at the pubic joint at the front (Vleeming 2008). Standing, walking and sitting all become harder to keep up for long, and the diagnosis is only reached once lumbar causes have been excluded, which is a clinician's job and not a reader's.

How each one behaves is the more useful separator in practice. Pelvic girdle pain is something you load into. POGP's list of the activities that bring it on is walking, standing on one leg to dress or climb stairs, moving the legs apart getting in or out of bed or a car, lying in certain positions, and intercourse. The pain tends to arrive with the movement and ease off once you have stopped. A single electric jab out of nowhere, with nothing to blame it on, behaves differently.

None of that is a test, and the three labels overlap a good deal. In clinic the same woman often has pelvic joint pain she can reproduce on demand and separate sharp jabs she cannot, which is one reason the names get swapped around between appointments. Pelvic girdle pain and SPD deals with the other naming muddle, and the pregnancy back and pelvic pain program covers the pelvic joint side properly.

One thing the three have in common is a side. Lightning crotch is usually felt on one side, round ligament pain is typically one-sided, and so is a good deal of pelvic girdle pain, so a pain that only ever happens on the left or only on the right is not a clue to which of them it is. Pelvic girdle pain on one side goes into what a consistently one-sided pelvic pain does and does not tell you.

Which trimester does each one start in?

The sources we can read do not fix a trimester for round ligament pain, and we are not going to invent one. The NHS page that describes it gives no timing at all. For pelvic girdle pain the RCOG does commit: it says symptoms are more common later in pregnancy, while also noting that the condition affects about 1 in 5 pregnant women overall. POGP supplies the other half of that, which matters if you are early on: this pain can happen at any stage of pregnancy, so being at 14 weeks does not rule it out.

The timing question matters less than it looks. A sharp pelvic pain at 35 weeks is read differently from the same pain at 20 weeks, not because the ligament has changed, but because the list of things that need excluding has. The nearer you are to term, and the further you are below 37 weeks, the more the first question becomes whether something is starting. That is a question for your maternity team, and the week you are in is one of the first things they will ask.

What helps, and what to do in the moment

In the moment there is not much to do beyond stopping the movement, putting a hand under the bump, and changing position until it passes. It is usually over before you can do any of that, which patients find frustrating.

The useful work is in the ordinary jobs that keep setting it off, and it is the same set of changes the pelvic girdle pain program uses. Turn over in bed with your knees together and a pillow between them. Get up by rolling onto your side first and pushing up, which the log roll page teaches step by step. Sit down on the car seat before you swing both legs round together, keeping your knees and ankles close. Sit down to put on underwear, trousers and shoes.

Heat and pain relief both come with conditions, and the first condition rules heat out for this particular pain. The HSE's pelvic girdle pain guidance allows heat on tender areas such as the lower back, hips, bottom or between the legs, but says not to put it directly on your bump, not to use heat at all in the first 12 weeks, to wrap the pack in a towel, and to leave it on for a maximum of 20 minutes.

Round ligament pain sits low in the tummy and the groin, which is bump territory, so heat is not the answer for the sore spot itself. Where it earns its place is a back, hip or buttock that has become tender from bracing against the pain, and the conditions above hold there. For medicine, the NHS says paracetamol can be taken as directed unless your doctor or midwife has advised otherwise, and the RCOG says it is safe in pregnancy and may help in regular doses. Ibuprofen and the other anti-inflammatory painkillers are a different question: the NHS says to avoid ibuprofen in pregnancy unless a doctor or pharmacist has advised it, and that paracetamol is usually the best painkiller to take when you are pregnant. Anything stronger is a conversation with your midwife, doctor or pharmacist.

If there is gentle movement in your week already, keep it going at a level that does not stir the pain up. The program's starting guide is around 5 to 10 slow repetitions of the gentle pelvic and back movements, once or more a day, and your physio will adjust this to you. Treat that as a ceiling rather than a day-one target: start with however few you can do without the pain rising, stop if an exercise brings pain on while you do it, and leave it out and say so at your next appointment if it brings on pain that is still there that evening or the next morning. Check with your midwife or doctor before you start. None of it prevents a sharp jab from happening, and we found no study showing that any exercise does.

There is a point at which working around it on your own stops being the answer, and POGP puts a timeframe on it: if symptoms do not improve within a week or two, or they interfere with your normal day to day life, ask for help from your midwife, GP or physiotherapist, and you should be seen by a specialist pelvic health physiotherapist. That holds for the aching pelvis these jabs usually sit alongside. For the jabs themselves, the thing that decides the timing is what comes with them, which is what the warning list at the foot of this page is for.

When a sharp pelvic pain needs a phone call

Some of this is specific and worth having in plain numbers. The NHS asks you to call your midwife or maternity unit urgently if your waters break, if there is vaginal bleeding, if your baby is moving less than usual, if you are less than 37 weeks pregnant and think you might be in labor, if any contraction lasts longer than 2 minutes, or if you are having 6 or more contractions every 10 minutes. It says not to wait until the next day, and to call even in the middle of the night. MedlinePlus, writing for readers in the United States, gives a similar list and includes contractions with lower back pain or pressure in your groin or thighs, with more than 5 contractions in an hour among its reasons to be seen right away before 37 weeks.

Early pregnancy carries its own question. The NHS lists tummy pain low down on one side among the signs of a pregnancy growing outside the womb, alongside a missed period and other signs of pregnancy, vaginal bleeding or a brown watery discharge, pain in the tip of the shoulder, and discomfort when peeing or pooing, and it says those symptoms tend to show up between the 4th and 12th week. So a sharp one-sided pain low down in the early weeks gets reported rather than filed under a stretching ligament. The combination the NHS sends straight to emergency services or an emergency department is a sharp, sudden and intense pain in your tummy with feeling very dizzy or faint, feeling sick, or looking very pale.

Three further patterns do not wait for an appointment, whatever a sharp pain is doing. Numbness or altered feeling around your genitals or bottom, trouble starting to pee, not being able to pee at all, not being able to feel yourself pee, or losing control of your bladder or bowels is an emergency in its own right, when it is new and not normal for you. That group goes to an emergency department or emergency services first, ahead of a call to your maternity unit, because what it needs is an urgent scan of your lower back and, if the scan shows pressure on the bundle of nerves at the base of the spine, an operation to take that pressure off. A maternity unit cannot scan a spine.

Say when you arrive that you have numbness around your genitals or bottom and a change in how you pee, in those words, because that is the pair that moves it up the queue, and caught while the bladder is still working the outlook is better. Tell your maternity team as well, but do not wait for them to call you back, and do not drive yourself: the NHS asks you to get someone else to drive you or to call for an ambulance, and to bring any medicines you take with you. Take your maternity notes as well. Needing to pee more often is ordinary in pregnancy and is not what this is about. A bladder that has stopped emptying does not always hurt either, so no pain in it is not a reason to wait.

The other two have their own destinations. Pelvic or pubic pain that arrived in a single moment with a crack or a pop, or that has suddenly left you unable to stand, walk or put weight on a leg, goes to your maternity unit straight away, and to emergency services if you cannot stand or walk at all. While you wait, lie on your side with your knees together and a pillow between them, get help to move if there is someone with you, and do not stand on one leg or let your legs come apart, because a joint that has separated at the front of the pelvis is opened further by loading one leg at a time. And a one-sided calf or thigh that is newly swollen, warm or tender goes to your maternity unit, midwife or doctor straight away rather than waiting, because pregnancy and the first 6 weeks after giving birth both make a clot more likely. If you are also short of breath or have chest pain, that is emergency services.

Everything else gets mentioned rather than filed away. Tell your midwife or doctor about new pelvic pain even if you are fairly sure it is mechanical, and ask for a referral to a pelvic health physio if it is affecting how you move, sleep or get through the day. Pain in the groin covers the other structures that produce pain in that area, and signs of a weak pelvic floor is the page for leaking or heaviness, which often travels with pelvic pain and is worth raising at the same appointment.

Related exercise programs

Warning signs

Get emergency help now

Emergency: anything that looks life threatening, at any stage of pregnancy. Call emergency services without stopping to work out which line below fits: 999 in the UK, 112 in the UK and anywhere in Europe, 911 in the United States and Canada, 000 in Australia, 111 in New Zealand. Say how many weeks pregnant you are, and say it again to each new person you speak to (NHS).
Emergency: heavy bleeding from your vagina, for example soaking a pad soon after you put it on, or any bleeding with severe pain in your tummy, pain in your shoulder, or feeling sick, faint or dizzy. Call emergency services straight away.
Emergency: pelvic or pubic pain that has suddenly left you unable to stand, walk or put weight on one or both legs. Call emergency services if you cannot stand or walk at all, or you cannot get to a hospital safely. Until help reaches you, stay where you are rather than trying to get yourself up: lie on your side with your knees together and a pillow between them, and do not stand on one leg or let your legs come apart.
Emergency: a very high or a very low temperature, shivering you cannot control, breathing very fast or finding it hard to breathe, being confused or slurring your speech, skin, lips or a tongue that look blue, gray, pale or blotchy (on brown or black skin this can be easier to see on the palms of the hands or soles of the feet), or a rash that does not fade when you press it. Call emergency services, as this can be sepsis.
Emergency: numbness, tingling or altered feeling around or under your genitals, between your inner thighs, or around your bottom (anus), for example it feels different when you wipe after using the toilet. Call emergency services or go to an emergency department straight away. This can be a sign of pressure on the bundle of nerves at the base of the spine (cauda equina syndrome), which needs emergency treatment.
Emergency: you find it hard to start peeing, cannot pee, cannot feel yourself peeing or cannot control when you pee, or you do not notice when you need to poo or cannot control when you poo, and this is not normal for you. The same applies to a new change in how your genitals feel during sex, or new trouble getting an erection or ejaculating. Call emergency services or go to an emergency department straight away. These can also be signs of cauda equina syndrome.
Emergency: you suddenly become short of breath, you get chest pain or pain in your upper back that may be worse when you breathe in, you cough up blood, your heart is beating very fast, or you faint. Call emergency services straight away, even if your leg looks normal. These can be signs of a blood clot in the lungs (pulmonary embolism).
Emergency: hip or groin pain on one side that suddenly becomes much worse, or a leg that will not take your weight at all. Go to an emergency department straight away, and say you are pregnant and that the top of the thighbone may be involved, because pregnancy can weaken the bone there and weakened bone can crack. Call emergency services if you cannot stand or walk at all, or cannot get there safely.
Emergency: you have a lump in your groin and the pain in it is severe or came on suddenly, you cannot poo or pass wind at all, you are vomiting blood or your vomit looks like coffee grounds, or you have suddenly become confused. Call emergency services or go to an emergency department straight away, and do not try to push the lump back in yourself. A hernia that has become trapped can block the bowel or cut off the blood supply to whatever is caught in it (NHS).
Emergency: pain in your lower tummy or pelvis that is severe, is getting worse, or hurts when you move or touch the area, or that comes with feeling faint, dizzy or lightheaded, passing out, pain at the tip of your shoulder, trouble breathing, heavy bleeding from the vagina, or sudden confusion. Call emergency services or go to an emergency department straight away. Tell them if there is any chance you are pregnant.
Emergency: sciatica in both legs, or pain, tingling, numbness or weakness in both legs. The same applies if you lose feeling in one leg. Call emergency services or go to an emergency department straight away.
Emergency: you have had cancer, now or in the past, and your back or neck pain feels like a tight band around your body, or comes with pain spreading down an arm or leg, weakness, numbness or pins and needles in your arms or legs, trouble walking, or trouble controlling your bladder or bowels. Call your cancer team's emergency number straight away, or go to an emergency department if you do not have one or cannot get through. This can be cancer pressing on the spinal cord (metastatic spinal cord compression), which needs treatment straight away.
Emergency: you have thoughts of ending your life or of harming yourself or your baby and feel you might act on them, you have already harmed yourself, or you do not feel you can keep yourself or your baby safe. Call emergency services or go to an emergency department straight away.

Get help now, day or night

Who to call for every line below that says to contact your midwife or maternity unit: call them straight away, day or night, on the number in your maternity notes. In the first 12 weeks, before your first midwife appointment, the NHS routes these calls to a GP surgery or an early pregnancy unit, and from 12 to 19 weeks to a midwife or an early pregnancy unit, so you do not need a maternity unit of your own yet to be seen. Outside the UK, call your obstetrician, or the maternity or labor and delivery unit where your birth is booked. If you cannot reach anyone and you are worried, call NHS 111 in the UK, and anywhere, go to your maternity unit or an emergency department rather than waiting at home (NHS).
Any bleeding or spotting from your vagina, even if it is light and you have no pain. Contact your midwife or maternity unit straight away.
Your waters break, or you have a gush or trickle of fluid from your vagina, at any stage of pregnancy. Contact your midwife or maternity unit straight away.
Before 37 weeks, you have regular tightenings or contractions, period-type pains, or backache that is not usual for you. Contact your midwife or maternity unit straight away, as this can be a sign of early (premature) labor.
New back pain in the second or third trimester (from 13 weeks), even if you think it is PGP or ordinary backache. Contact your midwife or maternity unit straight away, as it can be a sign of early labor. Once they have checked it, follow their advice about when to call again.
Your baby is moving less than usual, you cannot feel your baby moving anymore, or the usual pattern of movements has changed. Contact your midwife or maternity unit straight away, even in the middle of the night. Do not wait until the next day, and do not use a home heartbeat monitor to check.
A severe headache that does not go away with simple painkillers, problems with your vision such as blurring or flashing lights, pain just below your ribs, sudden swelling of your face, hands or feet, being sick (vomiting), heartburn that does not go away with heartburn medicines, or feeling very unwell. Contact your maternity unit straight away, as these can be signs of pre-eclampsia, which needs checking and treating quickly. The same applies to a headache after an epidural or spinal anesthetic that gets worse when you sit or stand up and eases when you lie down. Call emergency services if you have a fit (seizure), or a headache that came on suddenly and is very severe. Call emergency services too if you have a headache with a stiff neck and either a high temperature or bright light hurting your eyes, as this can be meningitis.
Tummy pain that does not go away after you have rested for 30 to 60 minutes, or that comes with lower back pain, vaginal discharge that is unusual for you, regular cramping or tightenings, pain when you pee, or needing to pee suddenly or more often than usual (NHS). The same applies to back or pelvic pain that comes on suddenly, is getting worse quickly or is much worse than your usual pain. Contact your maternity unit straight away. Call emergency services if the tummy pain is severe, any pain comes with bleeding from your vagina, or tummy pain comes with pain in your shoulder or feeling sick, faint or dizzy.
Pelvic or pubic pain that came on in a single moment, for example during the birth, a fall or a wide step, with a crack, pop or tearing feeling over your pubic bone. Contact your maternity unit straight away, and ask them to check the joint at the front of your pelvis. While you wait, keep off it rather than walking it off: lie on your side with your knees together and a pillow between them, get help to move if there is someone with you, and do not stand on one leg or let your legs come apart. If you cannot stand or walk at all, or you cannot get to a hospital safely, call emergency services. Separation of that joint (pubic symphysis diastasis) is uncommon, is not the same as the pelvic girdle pain this page is about, is confirmed on a scan rather than by how much it hurts, and is first treated with a pelvic support belt and side lying, so ask about a belt at that appointment (Stolarczyk 2021). Pain that has built up over days or weeks, even when it is severe, is the usual pattern of pelvic girdle pain.
Back pain with a high temperature (38C or above), feeling hotter than usual or shivery, pain or burning when you pee, pee that looks cloudy, pink, red or brown, or pain in one or both sides of your back just under the ribs. Contact your midwife, maternity unit or doctor straight away, as this can be a urine or kidney infection, which is usually treated easily once someone has seen you (NHS). Call emergency services instead if you have any of the signs of sepsis in the emergency warnings above.
A calf or thigh that is newly swollen or getting more swollen, warm, tender, red or darker than usual, has swollen veins that are sore to touch, or has a throbbing or cramping pain that does not fit your injury or condition, or that feels different from normal muscle soreness after exercise. This can be a sign of a blood clot (deep vein thrombosis), especially after surgery, an injury, time in a cast or boot, a long trip or a spell of being much less mobile than usual. Get medical advice the same day. If you are also short of breath or have chest pain, call emergency services. Pregnancy and the first 6 weeks after giving birth also make a clot more likely, so if you are pregnant or gave birth in the last 6 weeks, contact your maternity unit, midwife or GP straight away.
You fall, or your bump is knocked or hit, for example in a car accident, even if you feel fine. Contact your maternity unit straight away so you and your baby can be checked.
Lower tummy or pelvic pain and you are pregnant or think you might be. Contact your midwife or maternity unit straight away if you are pregnant, or get medical advice the same day if you might be. Pain low in the tummy early in pregnancy needs checking, because a pregnancy can grow outside the womb (ectopic pregnancy).
You are out of breath when you lie down, or breathlessness comes with dizziness. Contact your maternity unit straight away. If you are severely short of breath when you are resting, or so breathless that you are gasping or cannot get your words out, call emergency services. Feeling a little more out of breath as your baby grows is common, but this pattern needs checking.

Get help today

Same day: a lump in your groin that becomes painful, hard or red, that you cannot push back in, or that comes with a bloated tummy, feeling or being sick, constipation or a high temperature. Get medical help the same day, in person rather than by phone, for example at urgent care or an emergency department, as these can mean a hernia has become trapped (NHS). Do not try to push the lump back in yourself.
Same day: dizziness, lightheadedness or feeling faint while you are exercising, or the room seems to spin. Stop, and sit down or lie on your side until it passes. Contact your midwife or maternity unit the same day, and do not exercise again until you have been checked, as dizziness is one of the signs to stop exercising in pregnancy. If you faint, it does not settle within a few minutes of keeping still, or you cannot stand or walk steadily, call emergency services.
Same day: a leg or foot that is getting weaker, for example your foot drags, catches on the ground or slaps down when you walk (foot drop). Get medical advice the same day. If the weakness is getting worse by the hour, go to an emergency department.
Same day: new back pain and you have had cancer, now or in the past. Get medical advice the same day and mention your cancer history. If you are being treated for cancer now, contact your cancer team the same day.
Thoughts of suicide or of harming yourself or your baby, even if you do not plan to act on them. Get urgent help the same day from your GP, midwife or health visitor, or NHS 111 in the UK. In the UK, you can also talk to Samaritans on 116 123.

Book an appointment

Within a few days: hip or groin pain, usually on one side, that is worse when you put weight on that leg, that makes you limp or need a stick or crutch, or that has not eased with position changes and pacing. Ask your midwife or doctor for a review, and say the pain is in your hip rather than only your pelvis. While you wait, take the weight off that leg where you can: lean on a crutch, a stick, a shopping cart or a stroller, use the rail and one step at a time on stairs, sit down for jobs you would do standing on one leg, and do not push through pain you have to limp on. Pregnancy and the weeks after the birth can cause a temporary weakening of the bone at the top of the thighbone, which is uncommon, is often read as pelvic girdle pain for weeks, and shows up on an MRI scan, which is the test to ask about when hip pain has no other explanation (Morton 2024). If the pain suddenly becomes much worse, or that leg will not take your weight at all, do not wait for the review: go to an emergency department straight away, as the emergency warnings above say.
Within a few days: a new lump or swelling in your groin, especially one that gets bigger when you cough, sneeze or stand and smaller when you lie down. Tell your midwife or doctor, because a lump there needs examining rather than explaining, and an ultrasound scan is what separates swollen veins alongside the round ligament from a hernia (Yeo 2021). Do not try to push the lump back in yourself, and use the same day line above instead if the lump becomes painful, hard or red or you cannot push it back in.
Low mood, anxiety or stress that is affecting your day to day life, or pain that is causing you considerable distress. Tell your midwife or doctor and ask what support is available, because this is part of what gets treated rather than something to put up with (NHS; RCOG; POGP).

Common questions

What is lightning crotch and what does it feel like?

Women describe a jolt: a sharp, electric, stabbing pain low in the pelvis, in the vagina, up inside, or near the pubic bone, lasting a second or two and then gone. Some get it once, some get a run of them over an afternoon. The phrase is not a medical term and we could not find a clinical source that defines it, so it describes a sensation rather than naming a cause. That matters, because the same sensation can come from a stretching round ligament, from the pelvic joints, or from something that needs checking. What you can describe usefully, and what is worth saying at your next contact, is where it is, how long each one lasts, what you were doing, and whether anything else came with it.

What is lightning crotch a sign of?

Nobody can answer that from the sensation. There is no source we could read that links it to labor starting, or to any particular stage, so anyone who tells you it means the baby has dropped or that labor is days away is guessing. What is worth knowing is the other direction. The NHS lists regular tightenings, period-type pains, backache that is not usual for you, and a gush or trickle of fluid as reasons to call your midwife or maternity unit if you are less than 37 weeks pregnant, and MedlinePlus puts contractions with lower back pain or pressure in your groin or thighs on the same kind of list. If any of those are with your sharp pain, it is a phone call now, not a question for a search box. If none of them are, the sharp pain still gets mentioned at your next contact.

Where is round ligament pain felt?

Low down on one side of the tummy, in the groin, and sometimes travelling down toward the labia, which follows the path of the ligament itself. The NHS describes it as a sharp cramp on one side of your lower tummy and groups it with the ordinary stretching pains of pregnancy, the ones that are mild and settle when you change position, rest, open your bowels or pass wind. One side is the usual pattern, and which side varies. The round ligaments are each about 10 to 12 cm long and run from the upper corners of the womb, out through the groin, and end in several strands in the labia (Yeo 2021), so pain following that line is doing what the anatomy suggests.

What helps round ligament pain in pregnancy?

In the moment, stop the movement that set it off, support your bump with a hand, and change position rather than pushing through. Over a day, the changes that help are the ones that take the sudden stretch out of ordinary jobs: turn over in bed with your knees together, get out of bed by rolling onto your side first, and swing both legs together in and out of the car. Heat is not the answer for the sore spot itself: the HSE's pelvic girdle pain advice allows heat on tender areas such as the lower back, hips, bottom or between the legs, but says not to put it on the bump, and round ligament pain sits low in the tummy and the groin. For a back, hip or buttock that has gone tender from bracing, the HSE's conditions are no heat in the first 12 weeks, wrapped in a towel, and 20 minutes at most. For pain relief, the NHS says you can take paracetamol as directed unless your doctor or midwife has told you otherwise, and the RCOG says paracetamol is safe in pregnancy and may help in regular doses. Ibuprofen is a different question: the NHS says to avoid it in pregnancy unless a doctor or pharmacist has advised it. Ask your midwife, doctor or pharmacist before you take anything else.

Can you get lightning crotch when you are not pregnant?

People do use the phrase outside pregnancy, and this page cannot help with that version of it. We write about the musculoskeletal side of pregnancy, and sharp pain low in the pelvis in someone who is not pregnant has a different list of causes behind it, including gynecological and urinary ones that need a doctor rather than a physio. The honest answer is to take it to your own doctor and have it assessed, rather than borrowing an explanation written for a growing womb. The same applies after the birth: if sharp pelvic pain is new or persisting postnatally, raise it at your postnatal check or sooner, and the postnatal program is the page written for that stage.

References

NHS. Stomach pain in pregnancy. Page last reviewed 18 November 2024. https://www.nhs.uk/pregnancy/common-symptoms/stomach-pain/
NHS. Pelvic pain in pregnancy. Page last reviewed 12 December 2022. https://www.nhs.uk/pregnancy/common-symptoms/pelvic-pain/
NHS. Back pain in pregnancy. Page last reviewed 10 January 2024. https://www.nhs.uk/pregnancy/common-symptoms/back-pain/
NHS. Premature labour and birth. Page last reviewed 10 January 2024. https://www.nhs.uk/pregnancy/labour-and-birth/premature-labour-and-birth/
NHS. Signs that labour has begun. Page last reviewed 9 November 2023. https://www.nhs.uk/pregnancy/labour-and-birth/signs-that-labour-has-begun/
NHS. Pregnancy symptoms you need to get help for. Page last reviewed 24 June 2026. https://www.nhs.uk/pregnancy/common-symptoms/pregnancy-symptoms-you-need-to-get-help-for/
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Written and checked by the PocketPhysio editorial team. Last updated 2026-10-23.

This page is general education, not a diagnosis or a personal treatment plan. See a physiotherapist or doctor for advice about your own situation.