Authors' objectives

To assess the efficacy of noninvasive stimulation at the Neiguan P6 acupoint in reducing nausea and vomiting in pregnant women.

Searching

MEDLINE was searched from 1966, CINAHL from 1982, and PsycINFO from 1967, using the following keywords: 'nausea/vomiting of pregnancy', 'acupressure', 'early pregnancy discomforts', 'pregnancy complications', 'nausea therapies', 'acupuncture', 'pressure', and 'nausea prevention and control'. The reference lists of identified studies were also examined.

Study selection

Assessment of study quality

No formal assessment of validity was undertaken, although some aspects of validity were commented upon in the data extraction table and in the text of the review.

Data extraction

The authors do not state how the data were extracted for the review, or how many of the reviewers performed the data extraction. The following information were reported in tabular format: author and year of publication, study design, the number of participants per treatment arm, intervention, outcome measures, and results.

Methods of synthesis

Results of the review

Eight studies (702 women) were included: 2 placebo-controlled, double-blind, cross-over randomised controlled trials (RCTs; n=69), 3 crossover RCTs (n=196), 1 RCT (n=60), one controlled trial (n=350), and one pre-test post-test study (n=27).

Acupressure on nausea and vomiting (7 studies): 6 studies reported significant reductions with acupressure, compared with the control treatment. The study reporting no effect (crossover RCT with 157 women) showed a significant decrease in nausea and vomiting for both active treatment and placebo groups (p<0.0009).

Sensory afferant stimulation (1 randomised cross-over study, the sample size was unclear): 15 out of 25 women reported a significant reduction in nausea and vomiting.

Acupressure and affective state (1 crossover RCT with 16 women): acupressure reduced nausea, anxiety, depression, psychosocial dysfunction, and dysfunction in performing activities of daily living (p<0.05).

There were several methodological flaws associated with the primary studies. These included poor questionnaire response rates; small sample size; women unsure about positioning of self-applied bands; no differentiation between nausea and vomiting; no specification of uni- or bilateral application; lack of control group; inclusion and exclusion criteria were unclear; the estimation of gestational age was described generally, and only 2 studies confirmed gestational age using ultrasound; the pressure application time varied both between and within studies; and in some cases, the placebo control actually caused some surface pressure to the Neiguan point.

Authors' conclusions

The majority of studies demonstrated that acupressure could significantly reduce the amount of nausea and vomiting associated with early pregnancy.

CRD commentary

The aims were stated, and the focus of the review was described in terms of the participants and interventions. The inclusion criteria were not defined in terms of study design or outcome. Three relevant databases were searched and the search terms were specified. However, there was no report of any language restrictions; there was no attempt to locate unpublished material, thus raising the possibility of publication bias; and there were no details provided on the methods used to select studies. The primary studies were not restricted by study design and validity was not formally assessed, though some aspects of validity were commented upon in the data extraction tables and in the text. Some relevant information on the primary studies was presented in tabular format but methods used to extract data were not described. A narrative review was appropriate given the heterogeneity among studies, but evidence from better quality studies was not highlighted. The discussion included consideration of the methodological flaws in the primary studies.

The conclusions should be interpreted with caution given the methodological concerns expressed by the authors, and the lack of detail of the methods used to conduct the review.

Implications of the review for practice and research

Practice: The authors state that acupressure has been proven effective in the relief of nausea and vomiting in pregnancy.

Research: The authors state that the studies need to be replicated using tighter control and should address the weaknesses discussed in this review.

Bibliographic details

Freels D L, Coggins M. Acupressure at the Neiguan P6 point for treating nausea and vomiting in early pregnancy: an evaluation of the literature. Mother Baby Journal 2000; 5(3): 17-22.

Other publications of related interest

Dundee JW, Sourial FB, Ghaly RG, Bell PF. P6 acupressure reduces morning sickness. J R Soc Med 1988;81:456-7.

Indexing Status

Subject indexing assigned by CRD

MeSH

Acupressure; Female; Nausea; Pregnancy Complications; Vomiting

AccessionNumber

12000005387

Database entry date

31/03/2002

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.