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Common side-effects of pregnancy

Morning sickness, acid reflux, constipation

Pregnancy presents the body with a number of challenges, many of which can produce symptoms and cause problems. Many side effects of pregnancy are not serious for mother or baby, although complaints like morning sickness, acid reflux and constipation can be very unpleasant.

What conditions may affect my pregnancy?

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Morning sickness

Morning sickness is one of the most common side effects of pregnancy, specifically in early pregnancy. About 9 out of 10 pregnant women experience morning sickness in some way, either feeling sick (nausea) or being sick (vomiting), or both. For most women this unpleasant problem starts at around 6-7 weeks of pregnancy, and is better by week 14.

There is a great variation in how severe it is. In some women it is very mild. Others have a very severe version of morning sickness called hyperemesis gravidarum. See the separate leaflet called Morning Sickness in Pregnancy.

Acid reflux in pregnancy

Acid reflux is sometimes referred to as heartburn, dyspepsia or indigestion. It's another common side effect of pregnancy, occurring in around half of all pregnancies. Typical symptoms include heartburn, tummy or chest pain, an acid taste and feeling bloated.

The symptoms of heartburn may be helped by lifestyle changes such as:

  • Sitting up and not lying down just after eating.

  • Raising the foot of your bed when sleeping.

  • Eating small frequent meals, and not eating within three hours of going to bed.

  • Reducing fatty or spicy foods, fruit juice, chocolate and caffeine.

Antacid preparations such as Gaviscon® reduce acid reflux symptoms in pregnancy. Antacid products containing sodium bicarbonate or magnesium trisilicate should be avoided in pregnancy. Other medicines such as omeprazole may be considered if symptoms are severe and not controlled with antacids.

See also the leaflet Acid Reflux and Oesophagitis (Heartburn) for more information.

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Constipation in pregnancy

Constipation is a very common side effect of pregnancy. It means passing hard stools (faeces), sometimes painfully. It can also involve going to the toilet to open the bowels less often than usual. Constipation can cause a great deal of tummy (abdominal) discomfort, cramping and wind (flatulence). It may also cause pain when passing stools.

Stools are hard because they are drier and constipation can be caused by not drinking enough. By the time you pass a stool it has come all the way through the bowel. The speed at which it does this (called the 'transit time') varies. Whilst the stools are in the bowel, they tend to start to dry out because your body takes water from them. The longer the stools spend in your bowel, the more water your body will take back and the harder and drier they become.

The stools move through the bowel more slowly if there is a lack of fibre and fluids in the diet to bulk up the stools. In pregnancy, the bowels tend to be more relaxed and to work more slowly anyway. This is partly due to pregnancy hormones and partly due to the growing womb (uterus) putting pressure on the bowels.

Bowels work more quickly and effectively when you are well exercised, as the tummy muscles help stimulate the bowel. In pregnancy the tummy muscles are rather stretched and do this job less well.

What are the typical symptoms of constipation?

These include:

  • Opening the bowels less than usual. ('Usual' frequency varies between people but typically people would normally go once or twice a day. If you open your bowels less than three times a week you have constipation.)

  • Passing hard, pellet-like stools.

  • Tummy cramps.

  • Wind.

How do I deal with constipation during pregnancy?

You can improve symptoms of constipation by doing things that speed the passage of stools through the bowel and by making sure there is plenty of water in your system. Water can make the stools soft. So if you are constipated you should:

  • Increase the amount of water you are drinking.

  • Make sure your diet is rich in fibre-containing foods.

  • Take regular exercise.

If none of this proves to be enough, see your doctor or midwife about the possibility of taking laxatives.

'Softening' laxatives
These simply soften the stools. They tend to cause more wind and are not always helpful in pregnancy. This is because they don't tend to speed the passage of the stool very well through the bowel.

'Stimulant' laxatives
These tend to make the bowel work faster. They are more effective than softening laxatives in pregnancy. However, they can cause cramping pains and wind as they start to work.

See the separate leaflet called Constipation.

Breathing difficulties in pregnancy

As the womb (uterus) grows, many women start to feel that they can't get their breath; or, they feel that they can't get enough breath. It's an unpleasant feeling and you may feel rather panicky. This can lead to over-breathing (hyperventilation), which will also make you feel odd.

The feeling of breathlessness is usually caused by the growing womb occupying space in the tummy (abdomen). This means that the diaphragm (the big muscle underneath your lungs that pulls them open when you breathe) has less room to expand the lungs. This becomes more marked as the pregnancy advances.

The important thing is that it's a FEELING of breathlessness. It doesn't mean you are not getting enough air. If you were to breathe with only half of your lungs, you would still get enough air. However, the sensation that the lungs can't quite expand enough FEELS like a real shortage of breath.

Unfortunately, if you try to breathe deeper and faster to make up for this, you can feel even more breathless. This is called hyperventilation. When you do it, you increase your oxygen levels to well above those that you need; you also reduce your carbon dioxide levels to much lower than normal. The end result is that you can feel panicky, tingly, dizzy and faint. Hyperventilation is quite common in pregnancy.

There are some other causes of breathlessness in pregnancy which need your doctor's help; some of them are serious. Therefore, if you are severely breathless, you should contact your doctor urgently.

What other causes of breathlessness are there in pregnancy?

The most common of these are:

  • Asthma (which you would normally already know you have but which can become worse in pregnancy).

  • Anaemia - in which the iron levels in the blood have fallen and the blood can therefore carry less oxygen. If anaemia is severe then this can significantly reduce the amount of oxygen carried to the brain. You then have to take more breaths to make up for it. This can be enough to make you feel breathless.

  • Other causes of breathlessness in pregnancy, such as a clot in the lung (pulmonary embolus) and fluid in the lung, are thankfully very rare.

How do I deal with mild but troublesome symptoms of breathlessness in pregnancy?

The following may help:

  • Taking it easy, resting and trying to relax will make the symptoms subside.

  • If you are over-breathing then contact your doctor for advice about breathing exercises.

  • Gentle exercise like a walk can also help. This will also improve your sleep and make you feel fitter and less tired, both of which help indirectly.

Continue reading below

Itching in pregnancy

Itching is a very common side effect of pregnancy. It may be all over the body or it may be localised to one area. All-over itching is often due to skin dryness and stretching of skin, particularly on the tummy (abdomen).

Some women develop a pregnancy-related itch, usually in the last few weeks of pregnancy. The skin is not dry, and there is often no rash, yet the itch can be intense and it is often felt all over the body.

Less commonly, itching in pregnancy - particularly in the later weeks - is due to a small gland (the gallbladder) underneath the liver not working properly. This can sometimes cause problems for your baby. Therefore, if you do develop itching and have no skin rash, it is important to see your doctor or midwife. He or she may arrange for a simple blood test to make sure that your gallbladder is working properly. See the separate leaflet called Obstetric Cholestasis.

Specific areas of itching, particularly small patches, are often due to skin infections. These can be caused by fungi such as tinea or thrush, or by germs (bacteria) which may cause hair follicles to become infected (folliculitis).

Occasionally, local or all-over itching may be caused by scabies. Scabies is a tiny mite, rather like a head louse, that gets into the skin and causes intense itch. It can come from close contact with someone else who has it; or, occasionally it can come from sleeping on a mattress which has been used by someone with scabies. Treatment is with cream or lotion from your doctor.

How do I deal with itching in pregnancy?

The following methods may help:

  • First and foremost, don't scratch. This will make you itch more.

  • If the itching is unbearable, rub the area with an ice cube. This will tend to calm down the itch by reducing blood flow to the skin. This is because chemicals which cause itch are carried in the blood, so if you slow the blood flow then fewer itch-causing chemicals reach the area.

  • Use simple moisturising creams (aqueous creams) on itchy areas, particularly if they are dry. Use them generously.

  • If you have an itch or rash in one specific place, see your doctor who may be able to prescribe a cream to solve it.

  • If you suddenly develop all-over itching or itching that is severe, see your doctor to exclude gallbladder problems.

Piles in pregnancy

Haemorrhoids - often called piles - are swollen (also called varicose) veins around the back passage (anus). They can be intensely itchy, can ache and throb and may cause bleeding on opening the bowels. This bleeding is bright red and it can be quite heavy.

Piles are due to swelling and bulging of the veins as they dip to their lowest point around your bottom. Pressure from pushing to open your bowels increases pressure on these veins. Pressure from the weight of your baby sitting in your womb (uterus) also pushes on these veins, so piles are often a side effect of pregnancy. Some people are more prone than others to piles. We inherit the tendency for our veins to have tougher walls that don't bulge, or softer veins that give way more easily. If you have a tendency to varicose veins in your legs then you may also have a tendency to piles.

Piles are made worse by constipation, when you are pushing more, and by later pregnancy when the baby weighs more. Piles can also be made worse by pushing in labour, which also increases the pressure on them.

How do I deal with piles during pregnancy?

You can help by avoiding constipation (see above), drinking plenty of non-alcoholic fluids, taking regular exercise and having a good fibre intake to keep the stools (faeces) soft.

If this is not sufficient, see your doctor or midwife to ask for help. Medical treatment of piles in pregnancy is usually with creams and suppositories. Treatments are aimed both at stopping the soreness and itch and by making the piles less inflamed (this shrinks them and reduces their tendency to bleed).

If all else fails, piles can be treated with an operation. This is done either by:

  • Tying tight bands around them.

  • Injecting them with chemicals to make them shrink.

  • Removing them.

All these treatments would truly be a last resort. None of them is pleasant; besides which, the piles could easily come back before the pregnancy is over. They usually go by themselves afterwards, a few weeks after the pregnancy ends. See the separate leaflet called Piles (Haemorrhoids).

Varicose veins in pregnancy

Varicose veins are swollen veins, most commonly in the legs and most often down the back of the calf and on the inside of the thigh. They can also occur in the vulva, in the fleshy outer lips on either side of the vagina.

Varicose veins result when pressure on a vein makes the vein wall give and bulge, rather as a balloon gives when it is blown up. Increased pressure in the veins occurs when there is increased weight in the tummy (abdomen), so varicose veins are often a side effect of pregnancy. This slows down the upwards return of blood back towards the heart. This means that they often occur or worsen during late pregnancy. Pregnancy also tends to make the vein walls softer which makes varicose veins occur more easily.

What are the typical symptoms of varicose veins?

These include:

  • Aching and pain in the legs.

  • Swelling of the feet and ankles.

  • Vulval varicose veins, which cause aching and throbbing in the vulval area. This is worse on standing.

How do I deal with varicose veins?

The following methods may help:

  • Put your legs up when you are sitting, with your feet higher than your hip joint. This tends to encourage the veins to drain.

  • Wear support tights (medium strength at least), putting them on in the morning first thing before your veins have had a chance to swell.

  • Walk around as much as possible. The working muscles of your calves are the pumps that try to send the blood from the veins back up into your body.

See the separate leaflet called Varicose Veins.

Vaginal discharge in pregnancy

It is normal to produce more vaginal discharge than usual during pregnancy, and you may notice this. It is due to the pregnancy hormones and the increase in blood supply to the vulval tissues. Increased vaginal discharge in pregnancy is entirely normal. It may be enough for you to need to wear a pad.

A normal discharge is creamy and pale in colour, does not smell bad and does not cause itch. See your doctor if:

  • The discharge has a strong or unpleasant odour.

  • The discharge is associated with itch or soreness.

  • You have pain on having sex (intercourse).

  • You have pain passing urine.

These problems may be caused by vaginal or bladder infection, either by thrush or by germs (bacteria). Take a urine sample with you when you go, and be prepared to be examined. If your doctor thinks you have an infection, you may be prescribed pessaries, creams or medicines called antibiotics.

See the separate leaflet called Vaginal Discharge (Female Discharge).

Pelvic ligament pain in pregnancy

Many women experience pain in the lower tummy (abdomen) as the baby grows. This typically starts at around 14 weeks and goes on into late pregnancy. It is due to the growing womb (uterus) pulling on the structures (round ligaments and the broad ligament) which hold it in place. This occasional side effect of pregnancy usually causes a stabbing pain down one or both sides of the tummy and sometimes down into the hips and genital area. The pain can be quite marked.

Some women feel it particularly when they turn over in bed. It can be so sharp that some worry it may be appendicitis. The ligaments stretch and pull as your womb grows bigger, and can go into spasm. This causes pain, particularly on sudden large movements.

The pain can happen again in subsequent pregnancies.

How do I deal with pelvic ligament pain?

The following methods may help:

  • Warmth, such as a wheat bag or a warm bath may relieve pain.

  • Lying on the opposite side may help.

  • Taking care when moving around, keeping movements gentle, to try to avoid triggering spasms.

Time will help - symptoms usually settle in late pregnancy.

Note: make sure that your doctor or midwife knows that you are having the pain and has checked you to rule out other causes such as your appendix or a bladder infection.

It is also common to have minor crampy pains in the lower part of your tummy in very early pregnancy. These feel rather like mild period pains and usually settle quickly. If you have any bleeding, or pain when you pass urine, see your doctor quickly.

Backache in pregnancy

Backache is a common side effect of pregnancy. Most pregnancy backache is caused by strains and pulls of the muscles and ligaments of your back. It is caused by a combination of:

  • The extra weight you are carrying.

  • Your altered way of standing and walking (your posture).

  • The softening of the ligaments around your back which can allow things to move slightly more freely than usual.

There is very little you can do to cure the problem completely until after your baby is born. The usual treatments for back pain are limited in pregnancy. However, staying mobile will certainly help and you should speak with your doctor or midwife for advice.

How do I deal with backache in pregnancy?

The following methods may help:

  • Light exercise - brisk walking and exercises such as yoga.

  • Avoiding sitting or standing for long periods of time.

  • Avoiding heavy lifting including, if you can help it, toddlers wanting to be carried!

  • If you have to sit, supporting your lower back with a cushion.

  • Considering asking your doctor to refer you to a physiotherapist for advice on simple exercises.

  • Trying exercising in water.

  • Taking warm baths and simple painkillers such as paracetamol may be helpful: ask your doctor or midwife for advice.

See the separate leaflet called Pregnancy and Physical Activity.

Pelvic girdle pain in pregnancy

The symphysis pubis is the joint between the two halves of the pelvis at the front - down low, over the front of your bladder. It can become very painful in pregnancy - usually in late pregnancy but sometimes as early as 14 weeks. This is because the joint in the bone can become loosened and the bones separate a little and then rub against one another.

The joint softening is caused by softening to the ligament that holds together the bones. This does have a purpose in nature: the splitting of the pubic bone in this way widens the pelvic 'outlet' which is the exit route your baby will take in labour. This can be seen as a helpful preparation for labour. This is a small consolation for the pain.

Pelvic girdle pain can be severe. It is often worse on walking and on turning over in bed at night. It can be helpful to sleep with a pillow between the knees, which supports the shape of the pelvis. Pain is mainly at the front of the pelvis over the pubic bone, although pain can spread to the hips and tummy (abdomen). It can be a severe problem; some women may even struggle to walk and they then need a special belt or crutches.

Exercise and physiotherapy have been shown to help. Contact your doctor to discuss a referral to a physiotherapist who should be able to advise further.

Tingling and numbness in pregnancy

During pregnancy you tend to retain fluid, especially around joints. This is a hormonal effect, made worse by the fact that the total volume of blood is greatly increased in pregnancy.

Fluid retention around the wrists can compress the nerves that produce sensations in the hand. This can cause carpal tunnel syndrome - a tingling in the thumb and neighbouring two to three fingers. The syndrome can spread up the arm, is worse at night and is sometimes painful. See the separate leaflet called Carpal Tunnel Syndrome.

In pregnancy, often the only treatment needed is splints for the wrists. These are particularly useful when worn at night. Other options may be injections with medicines called steroids and, very occasionally, having an operation.

Other nerves can also be affected, particularly the nerve that supplies the skin at the side of the thigh, causing pain and numbness down the outside of the leg.

Leg cramps in pregnancy

Later on, cramp is a very common side effect of pregnancy, particularly in the legs. It often occurs at night and can wake you from sleep. When a cramp occurs you need to gently but firmly stretch the muscle to undo the cramping. This will relieve the pain.

Cramp is probably related to fluid retention and many women have a tendency to swollen legs in late pregnancy. This is because the growing baby puts downward pressure on the veins in the legs and water from the circulation gathers there. Elevating the foot of the bed sometimes helps.

It's important to remember that cramps are sudden severe pains which settle over seconds or a few minutes. If you have longer-lasting pain in your calf, particularly if you also have a swollen leg, you should speak with your doctor or midwife. They need to rule out the possibility of a clot in the veins of the calf (a deep vein thrombosis) which is a serious condition requiring immediate treatment.

How do I deal with leg cramps during pregnancy?

The following methods may help:

  • Magnesium supplements are sometimes used for cramps. There is currently no convincing evidence for supplements such as magnesium for cramps, but some people find them helpful.

  • If the cramps are not severe then massage and stretching the muscle out may be sufficient.

See the separate leaflet called Cramps in the Leg.

Dr Mary Lowth is an author or the original author of this leaflet.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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