Less common than back pain, and no UK figuresEmerging evidence
In 1,835 pregnant women in Australia, 12.4% reported neck pain, against 39.5% with back pain (we read that study's summary, not the full paper). In one Turkish hospital study of 184 women, 7.1% reported neck pain in the first trimester, 8.7% in the second and 10.9% in the third, though the paper's text and table disagree on whether that rise is real. In 300 women in Bangladesh it was 1.7%. There is no UK figure.
The UK's pelvic and obstetric physiotherapists (POGP) list neck pain and stiffness among the muscle and joint problems of pregnancy, most likely in the third trimester but possible earlier, and sometimes carrying on after the birth.
Sources 1, 2, 3, 4
Commoner after the birth, with feedingEmerging evidence
Neck pain with breastfeeding was reported by 51.7% of 310 mothers at clinics in Nigeria and 35.5% of 110 in Cameroon, mostly during feeds and usually lasting less than 10 minutes. In an online survey of 395 mothers in Poland, 48% had neck pain at least once a week; those who fed for longer had more pain, and those who preferred to feed lying down or on a bed or sofa had less intense neck pain than those feeding in a chair.
These are clinic and online surveys, which can't show cause and may not reflect mothers in the UK. In 471 mothers in Arabic-speaking countries, support during feeds, such as cushions, went with lower pain scores.
Sources 5, 6, 7, 8
It isn't just the bumpMixed evidence
Neck pain is reported from the first trimester, before much of a bump, and is commonest after the birth. POGP lists many possible contributors: changes in posture as the baby grows, more flexible joints, enlarged breasts, feeding in an awkward position, lifting and carrying after the birth, long spells sitting, injuries you already had, and your strength before pregnancy.
Posture does change in pregnancy, but differently in different women: a review of 87 studies found "no consistent biomechanical pattern", and in 30 women in Poland the upper back rounded slightly by the second trimester. In adults who aren't pregnant, people with neck pain had only slightly more forward head posture than people without, in studies that can't show which came first.
Sources 2, 4, 9, 10, 11
Breasts, bras and sleep: plausible, but little studiedEmerging evidence
No study has looked at breast size or bra fit and neck pain in pregnancy. In 339 women hospital staff who weren't pregnant, bra cup size didn't track neck and shoulder pain across sizes, and in 400 new mothers in Nigeria, breast size wasn't linked with upper back pain. POGP advises a supportive bra through pregnancy and after the birth, as a comfort step.
Sleep is often broken: "As your bump gets bigger, it can be difficult to get a good night's sleep", the NHS says, and across 17 studies about a third of women had poor sleep that lasted from pregnancy into the first year. No study has linked this to neck pain in pregnancy, but poor sleep and neck pain go together in other adults.
Sources 12, 13, 4, 14, 15
Headaches: common early, and the ones that need a callStrong evidence
"Headaches can be common in early pregnancy. They usually improve as your pregnancy goes on", and they don't harm your baby, the NHS says. A tension-type headache, a pressing ache on both sides with tight neck muscles, is about a quarter of headaches in pregnancy, a review says, and headaches in the first week after the birth are common.
A severe headache can be a sign of pre-eclampsia, which is most likely from 20 weeks but can happen at any point, and sometimes "develops in the days or weeks after your baby is born", the NHS says. In most cases pre-eclampsia is not severe, and blood pressure and pee checks at every antenatal appointment pick it up. In 151 pregnant women sent to neurologists with a sudden headache, most had a migraine or another primary headache; raised blood pressure, a fever or an abnormal examination pointed to another cause.
Sources 16, 17, 18, 19, 20
A headache after an epidural, and other rare causesEmerging evidence
After an epidural or a spinal, about 1 in 100 women get a headache from a small leak of the fluid around the spine, usually between a day and a week afterwards: "It is usually a severe headache ... which gets better when lying down and worse on sitting or standing", sometimes with neck pain or stiffness, a Cambridge hospital leaflet says. It can be treated, and "In 60-70% of cases, a blood patch will cure the headache within 24 hours".
A stiff neck with a fever, a very painful headache or a rash can be meningitis, which is rare but an emergency. A tear in an artery in the neck is "a rare complication of pregnancy and puerperium", a review says. A pinched nerve in the neck is uncommon at childbearing ages (63.5 per 100,000 women a year in one US population, peaking at 50 to 54), while carpal tunnel symptoms at the wrist are common in pregnancy: 34% of 639 Dutch women reported them.
Sources 21, 22, 23, 19, 24, 25
Where to get help, and how fastStrong evidence
In pregnancy, where to turn depends on how far along you are, the NHS says: your GP surgery or early pregnancy unit in the first 12 weeks, your midwife or early pregnancy unit from 12 to 19 weeks, and your midwife or maternity unit from 20 weeks. "Always call 999 if you think it's a life-threatening emergency", and call NHS 111 if you're not sure what to do.
A headache that came on suddenly and is extremely painful, or comes with weakness, a drooping face, speech problems or loss of vision, is a 999 call at any time, as are sudden breathlessness and chest or upper back pain. These are rare; the warning signs list them in full.
Sources 26, 27, 28, 29
When a scan or test helpsStrong evidence
Ordinary neck pain in pregnancy needs no scan: the story and an examination decide, and most neck problems improve within 8 weeks, NHS inform says. Blood pressure and pee checks at antenatal appointments look for pre-eclampsia.
With arm weakness, numbness or signs of pressure on the spinal cord, "you may be sent for other tests such as X-rays or scans", the NHS says. In pregnancy, UK radiology guidance says ultrasound or magnetic resonance imaging (MRI), which use no X-rays, should be considered first, that the few studies after MRI in pregnancy "have not revealed any adverse effects, but are very limited", and that the dose to the baby from diagnostic X-rays "should present no risk". Tell the radiographer you're pregnant: the NHS MRI form asks.
Sources 30, 17, 31, 32, 33
How it usually goesEmerging evidence
"Most neck pain only lasts a few weeks", the NHS says, and NHS inform expects the biggest change in the first couple of weeks and most problems to improve within 8 weeks. In pregnancy, these symptoms are most likely in the third trimester and can continue after the birth (POGP). Neck pain with feeds usually lasts minutes rather than all day.
Headaches early in pregnancy usually improve as it goes on. Carpal tunnel symptoms often ease after the birth, but in some women they last a year or more. No one can promise a timescale.
Sources 34, 30, 4, 5, 16, 35, 36