Heartburn in Pregnancy

• What is heartburn in pregnancy?
• Who gets heartburn in pregnancy?
• Who is more likely to get heartburn in pregnancy?
• Why does heartburn occur in pregnancy?
• How will heartburn in pregnancy affect me?
• How is a diagnosis made?
• What treatments are available for heartburn in pregnancy?
• Heartburn during lactation

What is heartburn in pregnancy?

Heartburn is a symptom commonly experienced by pregnant women such that some women and obstetricians even consider it to be a normal occurrence in a healthy pregnancy.

Despite its name, heartburn does not involve the heart. Instead, it refers to a burning sensation or warmth behind the lower end of the sternum (breastbone). The sensation may extend variable distances from the top of the stomach to the rear of the mouth. This is caused by a reflux of the acidic contents of the stomach. Other common accompanying symptoms include a bitter taste, fullness, burping and difficulty swallowing.

Heartburn may be a new symptom experienced by the woman or it may be an exacerbation of pre-existing gastro-oesophageal reflux disease. Symptoms typically occur towards the end of the first trimester or in the second trimester with the frequency and severity of the heartburn increasing with increasing gestational age.

Who gets heartburn in pregnancy?

Heartburn is a common complaint during pregnancy affecting 40-80% of pregnant women.

Who is more likely to get heartburn in pregnancy?

Increasing gestational age, the presence of symptoms prior to pregnancy and multiparity (multiple previous pregnancies) are reported risk factors. Increasing maternal age seems to have a protective effect.

Why does heartburn occur in pregnancy?

Several reasons for the increased incidence of heartburn during pregnancy have been put forward. These include:

• Influence of increased circulating levels of progesterone and oestrogen mediating relaxation of the sphincter that sits between the oesophagus and stomach (the lower oesophageal sphincter);
• Increasing abdominal pressure with the growing uterus; and
• Abnormal gastric emptying and changes in gut motility.

While the exact causal mechanisms have not yet been proven, the process is likely to be multifactorial involving several of the above mentioned factors.

How will heartburn in pregnancy affect me?

Heartburn in pregnancy is similar to heartburn in the general population. Individuals complain of a burning sensation behind the sternum (breastbone) that may extend variable distances up into the throat and rear of the mouth. Regurgitation (bringing up of stomach contents) is also common. Symptoms are typically worse after a meal and at bed time.

In some cases, the oesophagus can get irritated by the acidic contents of the stomach refluxing and oesophagitis (inflammation of the oesophagus) can occur. Fortunately, when heartburn occurs in pregnancy, complications such as oesophagitis rarely occur.

How is a diagnosis made?

A diagnosis can be made by the patient’s report of their symptoms and a physical examination to exclude other pathologies.

The doctor may ask several questions regarding the type of the discomfort experienced including the

• Site of the discomfort;
• Character e.g. burning, stabbing, shooting;
• When you first noticed the symptoms;
• How long the symptoms last;
• Any factors that make it better or worse;
• The presence of any blood in the refluxed material or from your rectum;
• Any other symptoms; and
• How this affects you.

The last question is an important one, as if the symptoms are mild and do not cause you concern, you may be able to avoid medical treatments.

On a case by case basis, the doctor may listen to your heart and lungs, take your blood pressure and/or feel your abdomen.

Further investigations are not usually required and it is important that investigations involving radiation are NOT performed in pregnant women in order to avoid radiation exposure to the foetus.

If symptoms are persistent, gastrointestinal endoscopy is the investigation of choice. 

What treatments are available for heartburn in pregnancy?

The treatment of any condition occurring during pregnancy is complicated by the need to avoid treatments that may be harmful to the foetus. The treatment of heartburn is no exception.

Lifestyle modifications and dietary changes recommended prior to medical treatments.

Lifestyle modifications

Several strategies can be used to help reduce heartburn symptoms including:

• Eating smaller meals more frequently – by not overfilling the stomach there is less pressure on the sphincter which normally acts to prevent the flow of stomach contents back up the oesophagus;
• Avoiding eating late at night – most women experience their symptoms more frequently at night, so by avoiding meals late at night you can increase the time between eating and lying down, which may improve your symptoms;
• Avoiding foods that trigger symptoms – if certain foods like spicy or oily foods seem to trigger your symptoms it may be best to avoid these foods;
• Elevating the head of the bed – this puts gravity on your side to make it harder for stomach contents to enter the oesophagus; and
• Chewing gum – can be beneficial as it stimulates the salivary glands and helps to neutralise the stomach acids.

Alcohol and tobacco should be avoided not only to reduce reflux symptoms but also to avoid exposing the foetus to these harmful substances.

For more information on the effects of tobacco smoke exposure on pregnancy, see Smoking and Passive Smoking During Pregnancy.

For more information on the effects of drinking during pregnancy, see Pregnancy and Alcohol Consumption.

It is important for pregnant women, irrespective of heartburn symptoms, to engage in healthy eating habits and to reap the benefits of gentle exercise.

For those women who do not improve satisfactorily following lifestyle and dietary changes, the benefits versus the risks of medical therapy will be considered. There are several different medications available.

Antacids

Antacids are drugs which act to lower the acidity of the stomach. They should be trialled before the use of other medications and have the advantage that they provide almost immediate relief from heartburn symptoms. There is limited data surrounding their safety for use in pregnancy, but they are generally considered safe.

Calcium containing antacids have the benefit of providing additional calcium supplementation. This may be of value since pregnancy and lactation place demands on the bodies’ calcium stores.

Antacids containing sodium bicarbonate should NOT be used during pregnancy due to possible side effects on mother and baby.

In practice, antacids should NOT be taken with iron supplements as gastric acid normally facilitates the absorption of iron. This means that if taken at the same time the decreased acidity generated will impair the bodies’ ability to absorb the iron.

Hence it is important to ask your Doctor which antacid is right for you. You should also talk to your Doctor before taking any supplements or other medications as it is possible for these to interact with each other causing an adverse reaction.

Histamine₂-receptor antagonists (H2RAs)

This class of drugs are the most commonly used drugs for the treatment of heartburn in pregnancy. H2RAs decrease the amount of acid produced by the acid producing cells (parietal cells) of the stomach.

Each of the four drugs in this class (cimetidine, ranitidine, famotidine and nizatidine) are considered category B drugs for the Australian categorisation of risk of drug use in pregnancy. This means that these drugs have only been taken by a limited number of pregnant women and women of child-bearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human foetus being observed. Studies of cimetidine, ranitidine and famotidine (class B1) in animals have not shown evidence of an increased occurrence of foetal damage, however animal studies involving nizatidine (class B3) have shown evidence of an increased occurrence of foetal damage, the significance of which is considered uncertain in humans.

Proton pump inhibitors (PPIs)

While proton pump inhibitors (PPIs) are considered the most effective drugs to control heartburn symptoms, data surrounding their efficacy and safety in pregnancy is limited. PPIs decrease gastric acid production, but by a different mechanism compared to the H₂RAs.

Collectively, PPIs are classified category B for use in pregnancy with the exception of omeprazole, which is category C. Category C medicines have caused or may be suspected of causing, harmful effects on the human foetus or neonate without causing malformations. These effects may be reversible. Due to the limited information regarding the safety of PPIs for use in pregnancy, their use is restricted to those women whose symptoms do not respond to other measures and/or mediations.

For more information, see Proton Pump Inhibitors.

Heartburn during lactation

Typically, symptoms of heartburn resolve quickly following delivery although some women continue to experience symptoms of heartburn in the postpartum period and require treatment. Drugs used for the treatment of heartburn have the potential to be excreted into the breast milk of nursing mothers. During pregnancy it is important to consult your doctor to decide which medication, if any, is right for you while you continue to breastfeed. You should also talk to your doctor before taking any supplements or other medications as it is possible for these to be excreted into the breastmilk.

Antacids

Aluminium and magnesium based antacids are not excreted into breast milk and represent a safe treatment option for the lactating mother.

Histamine₂-receptor antagonists (H2RAs)

Each of the H₂RAs are excreted into the breast milk, some up to four to seven times the concentration in the mother’s serum. Nevertheless, these drugs are considered safe for use during breastfeeding.

Nizatidine is not suitable for use in breastfeeding women as it has been linked to abnormalities of growth in animal studies. 

Proton pump inhibitors

There is little information regarding the excretion of proton pump inhibitors into breast milk. However, due to their chemical properties, it is thought that they are excreted into the breast milk and this has been confirmed by one study. In animal studies, proton pump inhibitors have been linked to abnormalities of growth and so are NOT recommended for use in breastfeeding women.

More information

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For more information on acid reflux and heartburn and related investigations, treatments and supportive care, see Acid Reflux and Heartburn.

For more information about pregnancy, including preconception advice, stages of pregnancy, investigations, complications, living with pregnancy and birth, see Pregnancy.

For more information on nutrition, including information on types and composition of food, nutrition and people, conditions related to nutrition, and diets and recipes, as well as some useful videos and tools, see Nutrition.

 

References

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7. Somogyi A, Gugler R. Cimetidine excretion in breast milk. Br J Clin Pharmacol. 1979;7(6):627-9. [Full text]