Interventions for nausea and vomiting in early pregnancy: a Cochrane Review

Interventions for nausea and vomiting in early pregnancy:

a Cochrane Review

Clinical

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Background• Can occur at any time of day• Most common in first trimester 6-12/40, but can

continue up to 20/40.• Persists beyond 20/40 in up to 20%• Associated with rising hCG, • Hyperemesis gravidarum is severe and persistent

vomiting, with weight loss >5%, dehydration and electrolyte imbalance, and affects 0.3-3%

• Nausea and vomiting experienced by 50-80%.

What Interventions?

Nice Guidelines:• Women should be informed that most cases of nausea and• vomiting in pregnancy will resolve spontaneously within 16• to 20 weeks of gestation and that nausea and vomiting are• not usually associated with a poor pregnancy outcome. If a• woman requests or would like to consider treatment, the• following interventions appear to be effective in reducing• symptoms:• • non-pharmacological• – ginger• – P6 acupressure• • pharmacological• – antihistamines (no specific drug )

BWH Guidelines:

– Reassurance – the condition is generally self-limiting and associated with a good prognosis

– Dietary advice - adequate oral fluid intake to prevent dehydration, frequent small meals with high-carbohydrate or high-protein content (avoid offensive odours, fatty foods, spicy foods, iron supplements)

– Oral anti-emetics if the patient's condition is unresponsive to oral fluids and dietary restrictions alone. Recommended first line drug is cyclizine 50mg po tds and second line drugs include prochlorperazine 5mg po tds, 3-6mg buccal bd or 25mg od rectally, metoclopramide 10mg po tds.

Clinical question

What interventions are effective and safe for treating nausea and vomiting in early pregnancy?

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Source: Matthews A, Dowswell T, Haas DM, Doyle M, O’Mathúna DP. Interventions for nausea and vomiting in early pregnancy. Cochrane Database of Systematic Reviews 2010, Issue 9. Art. No.: CD007575. DOI: 10.1002/14651858.CD007575.pub2.

Context• This builds on a Cochrane review of interventions for nausea

and vomiting in early pregnancy from 2003.


Methods• The Cochrane Pregnancy and Childbirth Group’s Trials Register

was searched by the Trials Search Co-ordinator in May 2010. This Register contains reports of trials identified from:

quarterly searches of the Cochrane Central Register of Controlled Trials (CENTRAL); weekly searches of MEDLINE; hand searches of 30 journals and the proceedings of major conferences; weekly current awareness alerts for a further 44 journals; and monthly BioMed Central email alerts.

• The search identified 55 studies (in 66 reports). 27 of these studies were included and 22 were excluded. Four trials are awaiting further assessment and two trials are ongoing.

• Outcomes are described approximately 3 days after the start of treatment.


PICO(S) to assess eligible studies• Participants: Women experiencing nausea, vomiting or retching in

pregnancy, where recruitment to a trial took place up to 20 weeks’ gestation. (Women with the severe illness, hyperemesis gravidarum are excluded and covered in another review.)

• Intervention: All interventions for nausea, vomiting or retching.• Comparison: Any other intervention, including placebo and usual care.• Outcomes: Primary outcomes: symptomatic relief (measured as reduction

or cessation of nausea, vomiting or retching), and adverse maternal and fetal/neonatal outcomes. Secondary outcomes: quality of life, and costs.

• Studies: Randomized trials. (Cross-over and quasi-randomised studies were excluded.)


Description of eligible studies• Twenty-seven trials were included, with a total of 4041 women. • Studies were found of the following comparisons:

– Acupressure (P6 point, including acustimulation and auricular) versus placebo or vitamin B6 (7 studies, 795 women)

– Acupuncture versus sham treatment and no treatment (2 studies, 648 women)

– Moxibustion (Traditional Chinese Medicine) versus Chinese drugs (1 study, 302 women)

– Ginger versus placebo, vitamin B6 or drugs (9 studies, 1077 women)– Vitamin B6 versus placebo (2 studies, 416 women)– Anti-emetic medications (6) versus placebo (6 studies with 803 women)


Results: symptom relief• No statistically significant difference between P6 acupressure and placebo

or vitamin B6.• Results for auricular acupuncture difficult to interpret, and no statistically

significant differences in the acupuncture study. • Improvements with both moxibustion and Chinese drugs, but this study is

poorly reported.• Two studies favoured ginger over placebo• Some studies favoured ginger over vitamin B6 and some favoured

vitamin B6 over ginger.• Vitamin B6 was better than placebo.• Of the anti-emetic medications studied, the combination of dicyclomine

(anti-cholinergic), doxylamine and pyridoxine was better than placebo.


Results: adverse effects and secondary outcomes • Adverse effects on the mother or baby

Maternal effects– Side-effects from acupressure bands (both placebo and treatment groups)– Heartburn from ginger

Fetal/neonatal effects– No studies found significant differences in adverse neonatal outcomes, but all

were too small to detect any likely differences

• Secondary outcomes– Quality of life was reported in few studies (and results were difficult

to interpret)– No studies reported on economic costs


Conclusions: current evidence• There is little strong or consistent evidence for any intervention, and it is not

possible to be confident in the effectiveness or safety of any of the interventions.

• The methodological quality of studies was mixed, with inadequate information on randomisation procedures and blinding in many studies; and the results were difficult to interpret and pool because of differences in participants, interventions, comparisons and outcomes.

• Some commonly recommended interventions, such as dietary and other behavioural advice, have not been studied.

• No studies had the statistical power to provide convincing evidence of the effects on relatively rare adverse outcomes.

• There was very little information on the psychological, social or economic effects of nausea and how these were affected by different interventions.


Limitations:• No research into cyclizine included• Limited research into prochlorperazine and

metoclopramide ( Bsat 2003)

Conclusions: future research• There is a need for specific and justified outcomes in research

on interventions for nausea and vomiting in pregnancy.• Several instruments have been used to measure outcomes and

some of these might help address this (for example, the Pregnancy Unique Quantification of Emesis and Nausea (PUQE) scale).

• Adherence to dietary and other advice should be measured consistently, because this may also affect symptom relief.

• Adverse effects, quality of life and cost outcomes need to be collected and reported.


Useful links• Cochrane Journal Club discussion points

• Interventions for nausea and vomiting in early pregnancy


Documents

Interventions for nausea and vomiting in early pregnancy: a Cochrane Review