Abstract
Introduction
Constipation, heartburn, and haemorrhoids are common gastrointestinal complaints during pregnancy. Constipation occurs in 11-38% of pregnant women. Although the exact prevalence of haemorrhoids during pregnancy is unknown, the condition is common, and the prevalence of symptomatic haemorrhoids in pregnant women is higher than in non-pregnant women. The incidence of heartburn in pregnancy is reported to be 17-45%.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent or treat constipation in pregnancy? What are the effects of interventions to prevent or treat haemorrhoids in pregnancy? What are the effects of interventions to prevent or treat heartburn in pregnancy? We searched: Medline, Embase, The Cochrane Library and other important databases up to July 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results
We found five systematic reviews, RCTs or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions
In this systematic review we present information relating to the effectiveness and safety of the following interventions: Acid-suppressing drugs, anaesthetic agents (topical), antacids with or without alginates, bulk-forming laxatives, compound corticosteroid and anaesthetic agents (topical), corticosteroid agents (topical), increased fibre intake, increased fluid intake, osmotic laxatives, raising the head of the bed, reducing caffeine intake, intake of fatty foods, and the size and frequency of meals, rutosides, sitz baths, and stimulant laxatives.
Key Points
Constipation, heartburn, and haemorrhoids are common gastrointestinal complaints during pregnancy.
Constipation occurs in 11-38% of pregnant women.
Stimulant laxatives may be more effective than bulk laxatives in improving constipation in pregnancy, although adverse effects, such as abdominal pain and diarrhoea, could limit their use.
Dietary fibre may improve constipation in pregnant women compared with placebo.
We don't know whether increasing fluid intake improves constipation in pregnancy. However, because of other health benefits, increased fluid intake may be recommended as one of the first measures to relieve constipation.
We don't have good evidence to show that bulk-forming or osmotic laxatives are of benefit for constipation in pregnancy.
Although the exact prevalence of haemorrhoids during pregnancy is unknown, the condition is common, and the prevalence of symptomatic haemorrhoids in pregnant women is higher than in non-pregnant women.
Rutosides improve the symptoms of haemorrhoids compared with placebo. However, further studies are needed to assess their potential adverse effects.
We don't know whether increased fibre and fluid intake are effective in relieving the symptoms of haemorrhoids in pregnancy, although it seems reasonable to encourage pregnant women to consume a fluid- and fibre-rich diet as a preventive measure.
We don't know whether stimulant laxatives, bulk-forming laxatives, or osmotic laxatives are effective in relieving symptomatic haemorrhoids in pregnancy, although, if constipation is associated with haemorrhoids, treating constipation with stimulant laxatives may relieve straining, and thereby provide some symptomatic relief.
We found no good evidence assessing the effects of topical anaesthetics, topical corticosteroids, or compound topical corticosteroids plus anaesthetics to treat symptomatic haemorrhoids in pregnancy. However, despite this, women who have painful complicated haemorrhoids may be offered topical anaesthetic agents unless contraindicated.
The incidence of heartburn in pregnancy is reported to be 17-45%.
Antacids may provide effective heartburn relief in pregnancy.
We don't know whether dietary and lifestyle modifications are of benefit to prevent or treat heartburn in pregnancy. However, there is consensus that lifestyle and dietary modifications, including avoiding fatty foods and caffeine, should remain first-line treatment for heartburn in pregnant women.
We also don't know whether acid-suppressing drugs such as ranitidine are of benefit to treat heartburn in pregnancy.
About this condition
Definition
Constipation: Some women will have experienced chronic constipation prior to becoming pregnant, and in others constipation develops for the first time during pregnancy. For a full definition of constipation, see review on constipation in adults. The diagnosis of constipation is mainly clinical, based on a history of decreased frequency of defecation, as well as on the characteristics of the faeces. An extensive evaluation is usually unnecessary for women who present with chronic constipation, or if constipation develops for the first time during pregnancy. Heartburn: Heartburn is defined as a sensation of "burning" in the upper part of the digestive tract, including the throat. It can be associated with oesophagitis. One study reported the results of endoscopy on 73 pregnant women with heartburn, and found endoscopic and histological evidence of oesophagitis in most women. As complications associated with heartburn during pregnancy are rare (e.g. erosive oesophagitis), upper endoscopy and other diagnostic tests are infrequently needed. Therefore, the diagnosis of heartburn is mainly clinical, based on the history. Haemorrhoids: Haemorrhoids (piles) are swollen veins at or near the anus, which are usually asymptomatic. Haemorrhoids can become symptomatic if they prolapse (the forward or downward displacement of a part of the rectal mucosae through the anus) or because of other complications such as thrombosis. Associated anal fissures (a break or slit in the anal mucosa) can also lead to symptoms. Haemorrhoids can be classified by severity: first-degree haemorrhoids bleed but do not prolapse; second-degree haemorrhoids prolapse on straining and reduce spontaneously; third-degree haemorrhoids prolapse on straining and require manual reduction; and fourth-degree haemorrhoids are prolapsed and incarcerated. Diagnosis of haemorrhoids is based on history and examination. Symptoms include bleeding, mucosal or faecal soiling, itching, and occasionally pain. Fourth-degree haemorrhoids may become "strangulated" and present with acute severe pain. Progressive venous engorgement and incarceration of the acutely inflamed haemorrhoid leads to thrombosis and infarction. The diagnosis of haemorrhoids is confirmed by rectal examination, and inspection of the perianal area for skin tags, fissures, fistulae, polyps, or tumours. Prolapsing haemorrhoids may appear at the anal verge on straining. It is important to exclude more serious causes of rectal bleeding. Assessment should include anoscopy to view the haemorrhoidal cushions. Haemorrhoidal size, and severity of inflammation and bleeding should be assessed.
Incidence/ Prevalence
Constipation: Constipation is common in pregnant women, and can develop during pregnancy or increase in severity during pregnancy. The prevalence of constipation in pregnancy is reported to be 11-38%. Parity or previous caesarean section have been associated with constipation. Heartburn: Heartburn is one of the most common gastrointestinal symptoms in pregnant women, with an incidence in pregnancy of 17-45%. In some studies, the prevalence of heartburn has been found to increase from 22% in the first trimester to 39% in the second trimester to 60-72% in the third trimester. However, one prospective cohort study found that, in most pregnant women, heartburn, acid regurgitation, or both began in the first trimester and disappeared during the second trimester; and another cohort study also found that gastrointestinal symptoms, such as heartburn and nausea, were more common in the first trimester. The study also found that primigravidae reported more gastrointestinal symptoms than multiparae. Haemorrhoids: Although the exact prevalence of haemorrhoids during pregnancy is unknown, the condition is common in pregnancy, and the prevalence of symptomatic haemorrhoids is higher in pregnant than in non-pregnant women. In a population of pregnant women in Serbia and Montenegro, haemorrhoids were present in 85% of women during the second and third pregnancy. Haemorrhoids are also a frequent complaint among women who have recently given birth, and they become more common with increased age and parity.
Aetiology/ Risk factors
Constipation: Constipation in pregnancy is probably caused by rising progesterone levels. Low fluid and fibre intake may also be contributing factors. There is some evidence that pregnant women consume less fibre than is currently recommended for the non-pregnant population. Low fluid intake has been linked to constipation in pregnancy, particularly in the third trimester. Some medications taken during pregnancy, such as iron salts and magnesium sulphate, have been also been linked to constipation. Hypothyroidism may also be a rare cause of constipation during pregnancy. Heartburn: The cause of heartburn during pregnancy is multifactorial. Increased amounts of progesterone or its metabolites cause relaxation of smooth muscle, which results in a reduction in gastric tone and motility, and a decrease in lower oesophageal sphincter pressure. It has also been found that, during pregnancy, the lower oesophageal sphincter is displaced into the thoracic cavity (an area of negative pressure), which allows food and gastric acid to pass from the stomach into the oesophagus, leading to oesophageal inflammation and a sensation of "burning". Pressure of the growing uterus on gastric contents as the pregnancy progresses may worsen heartburn, although some authors believe that mechanical factors have a smaller role. Heartburn may also be caused by medications taken during pregnancy, such as antiemetics. Haemorrhoids: Haemorrhoids result from impaired venous return in prolapsed anal cushions, with dilation of the venous plexus and venous stasis. Inflammation occurs with erosion of the anal cushion's epithelium, resulting in bleeding. Constipation with prolonged straining at stool, or raised intra-abdominal pressure as occurs in pregnancy, may result in symptomatic haemorrhoids. During pregnancy, delivery, and the puerperium, sphincteral muscles and pelvic floor structures could be modified in tone and position, leading to an alteration of the normal functioning of the haemorrhoidal cushion, which may predispose to symptoms.
Prognosis
Constipation: Constipation, if mild, is often self-treated with home remedies or non-prescription preparations. Primary-care providers usually are confident managing constipation in pregnancy, unless severe, refractory to conventional management, or if additional diagnostic studies are required. Therefore referral to a gastroenterologist is seldom necessary. Heartburn: Most cases of heartburn improve with lifestyle modifications and dietary changes, but in some cases severity may increase throughout the course of pregnancy. Haemorrhoids: In women with haemorrhoids, symptoms are usually mild and transient and include pain and intermittent bleeding from the anus. Depending on the degree of pain, quality of life can be affected, varying from mild discomfort to difficulty in dealing with the activities of everyday life. Treatment during pregnancy is mainly directed to the relief of symptoms, especially pain control. For many women, symptoms will resolve spontaneously soon after birth.
Aims of intervention
To prevent constipation, haemorrhoids, and heartburn in pregnancy; to relieve or reduce the severity of symptoms; to minimise and avoid adverse effects of treatment on the mother and fetus (including teratogenicity).
Outcomes
Constipation: Prevalence of constipation; frequency of bowel movements; straining at defecation; hard, lumpy stools; sensation of incomplete evacuation/tenesmus; quality of life (visual analogue scales, linear analogue scales, pain expectation scores [PES], numeric rating scales); adverse effects of treatment on mother; adverse effects of treatment on fetus (including teratogenicity). Heartburn: Prevalence of heartburn, symptom diaries, number of antacids used, adverse effects of treatment on mother, adverse effects of treatment on fetus (including teratogenicity). Haemorrhoids: Prevalence of haemorrhoids, bleeding, prolapse, pain, thrombosis, soilage, and pruritus; quality of life (visual analogue scales, linear analogue scales, PES, numeric rating scales); adverse effects of treatment on mother; adverse effects of treatment on fetus (including teratogenicity).
Methods
BMJ Clinical Evidence search and appraisal July 2007. The following databases were used to identify studies for this review: Medline 1966 to July 2007, Embase 1980 to July 2007, and The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials 2007, Issue 2. Additional searches were carried out using these websites: NHS Centre for Reviews and Dissemination (CRD) — for Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA), Turning Research into Practice (TRIP), and NICE. Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the author for additional assessment, using predetermined criteria to identify relevant studies. Study-design criteria for inclusion in this review were: published systematic reviews and RCTs in any language, at least single blinded, and containing more than 20 individuals of whom more than 80% were followed up. There was no minimum length of follow-up required to include studies. We excluded all RCTs described as ‘open', ‘open label', or not blinded unless blinding was impossible. We also searched for prospective cohort studies on: increased fibre intake and increased fluid intake for preventing or treating constipation in pregnancy; increased fibre intake and increased fluid intake for preventing or treating haemorrhoids in pregnancy; and raising the head of the bed, reducing caffeine intake, and reducing the size and frequency of meals and fatty food intake for the prevention and treatment of heartburn in pregnancy. We also searched for systematic reviews, RCTs, and cohort and case-control studies assessing adverse effects of rutosides in pregnancy. In addition, we use a regular surveillance protocol to capture harms alerts from organisations such as the FDA and the UK Medicines and Healthcare products Regulatory Agency (MHRA), which are added to the review as required. We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table ).
Table.
GRADE evaluation of interventions for constipation, haemorrhoids, and heartburn in pregnancy
| Important outcomes | Symptom relief, quality of life, adverse effects | ||||||||
| Number of studies (participants) | Outcome | Comparison | Type of evidence | Quality | Consistency | Directness | Effect size | GRADE | Comment |
| What are the effects of interventions to prevent or treat constipation in pregnancy? | |||||||||
| 1 (40) | Symptom relief | Increased fibre intake v no treatment | 4 | –1 | 0 | –2 | +2 | Moderate | Quality point deducted for sparse data. Directness points deducted for unspecific definition of constipation and for few comparators. Effect-size point added for odds ratio less than 0.2 |
| 1 (140) | Symptom relief | Stimulant laxatives v bulk-forming laxatives | 4 | –3 | 0 | 0 | +1 | Low | Quality points deducted for sparse data, uncertainty about randomisation, and no clear end-point. Effect-size point added for odds ratio less than 0.5 |
| What are the effects of interventions to prevent or treat haemorrhoids in pregnancy? | |||||||||
| 2 (150) | Symptom relief | Rutosides v placebo | 4 | –2 | 0 | 0 | +2 | High | Quality points deducted for sparse data, and for not reporting method of randomisation. Effect-size points added for RR less than 0.2 |
| What are the effects of interventions to prevent or treat heartburn in pregnancy? | |||||||||
| 1 (50) | Symptom relief | Antacids v placebo | 4 | –1 | 0 | 0 | 0 | Moderate | Quality point deducted for sparse data |
Type of evidence: 4 = RCT; 2 = Observational; 1 = Non-analytical/expert opinion. Consistency: similarity of results across studies Directness: generalisability of population or outcomes Effect size: based on relative risk or odds ratio
Glossary
- Grade 1 to grade 3 haemorrhoids:
Grade 1 haemorrhoids are bleeding haemorrhoids that do not protrude from the anus. Grade 2 haemorrhoids are haemorrhoids that protrude on defecation, but that are reduced spontaneously. Grade 3 haemorrhoids protrude on defecation, but can be replaced digitally.
- High-quality evidence
Further research is very unlikely to change our confidence in the estimate of effect.
- Low-quality evidence
Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
- Moderate-quality evidence
Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
- Sitz bath
A warm water bath taken in the sitting position. The water covers only the hips and buttocks.
Constipation in adults
Haemorrhoids
Disclaimer
The information contained in this publication is intended for medical professionals. Categories presented in Clinical Evidence indicate a judgement about the strength of the evidence available to our contributors prior to publication and the relevant importance of benefit and harms. We rely on our contributors to confirm the accuracy of the information presented and to adhere to describe accepted practices. Readers should be aware that professionals in the field may have different opinions. Because of this and regular advances in medical research we strongly recommend that readers' independently verify specified treatments and drugs including manufacturers' guidance. Also, the categories do not indicate whether a particular treatment is generally appropriate or whether it is suitable for a particular individual. Ultimately it is the readers' responsibility to make their own professional judgements, so to appropriately advise and treat their patients.To the fullest extent permitted by law, BMJ Publishing Group Limited and its editors are not responsible for any losses, injury or damage caused to any person or property (including under contract, by negligence, products liability or otherwise) whether they be direct or indirect, special, incidental or consequential, resulting from the application of the information in this publication.
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