A novel approach to hyperemesis gravidarum: evaluation by a visual analogue scale score and treatment with transdermal clonidine

Systematic evidence map of evidence addressing the top 10 priority research questions for hyperemesis gravidarum

OBJECTIVE

Knowledge gaps regarding hyperemesis gravidarum (HG) are substantial. We aimed to systematically identify and map recent evidence addressing the top 10 priority questions for HG, as published in 2021 in a James Lind Alliance Priority Setting Partnership.

DESIGN

Systematic evidence map.

METHODS

We searched MEDLINE and EMBASE on 12 January 2021 and CINAHL on 22 February 2021 with search terms hyperemesis gravidarum, pernicious vomiting in pregnancy and their synonyms. Results were limited to 2009 onwards. Two reviewers independently screened titles and abstracts to assess whether the studies addressed a top 10 priority questions for HG. Differences were discussed until consensus was reached. Publications were allocated to one or more top 10 research questions. Study design was noted, as was patient or public involvement. Two reviewers extracted data synchronously and both cross-checked 10%. Extracted data were imported into EPPI-Reviewer software to create an evidence map.

OUTCOME MEASURES

The number and design of studies in the search yield, displayed per the published 10 priority questions.

RESULTS

Searches returned 4338 results for screening; 406 publications were included in the evidence map. 136 publications addressed multiple questions. Numerous studies address the immediate and long-term outcomes or possible markers for HG (question 8 and 9, respectively 164 and 82 studies). Very few studies seek a possible cure for HG (question 1, 8 studies), preventative treatment (question 4, 2 studies) or how to achieve nutritional requirements of pregnancy (question 10, 17 studies). Case reports/series were most numerous with 125 (30.7%) included. Few qualitative studies (9, 2.2%) were identified. 25 (6.1%) systematic reviews addressed eight questions, or aspects of them. 31 (7.6%) studies included patient involvement.

CONCLUSIONS

There are significant gaps and overlap in the current HG literature addressing priority questions. Researchers and funders should direct their efforts at addressing the gaps in the top 10 questions.

Treatments for hyperemesis gravidarum and nausea and vomiting in pregnancy: a systematic review and economic assessment

BACKGROUND

Nausea and vomiting in pregnancy (NVP) affects up to 85% of all women during pregnancy, but for the majority self-management suffices. For the remainder, symptoms are more severe and the most severe form of NVP - hyperemesis gravidarum (HG) - affects 0.3-1.0% of pregnant women. There is no widely accepted point at which NVP becomes HG.

OBJECTIVES

This study aimed to determine the relative clinical effectiveness and cost-effectiveness of treatments for NVP and HG.

DATA SOURCES

MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, PsycINFO, Commonwealth Agricultural Bureaux (CAB) Abstracts, Latin American and Caribbean Health Sciences Literature, Allied and Complementary Medicine Database, British Nursing Index, Science Citation Index, Social Sciences Citation Index, Scopus, Conference Proceedings Index, NHS Economic Evaluation Database, Health Economic Evaluations Database, China National Knowledge Infrastructure, Cochrane Database of Systematic Reviews and Database of Abstracts of Reviews of Effects were searched from inception to September 2014. References from studies and literature reviews identified were also examined. Obstetric Medicine was hand-searched, as were websites of relevant organisations. Costs came from NHS sources.

REVIEW METHODS

A systematic review of randomised and non-randomised controlled trials (RCTs) for effectiveness, and population-based case series for adverse events and fetal outcomes. Treatments: vitamins B6 and B12, ginger, acupressure/acupuncture, hypnotherapy, antiemetics, dopamine antagonists, 5-hydroxytryptamine receptor antagonists, intravenous (i.v.) fluids, corticosteroids, enteral and parenteral feeding or other novel treatment. Two reviewers extracted data and quality assessed studies. Results were narratively synthesised; planned meta-analysis was not possible due to heterogeneity and incomplete reporting. A simple economic evaluation considered the implied values of treatments.

RESULTS

Seventy-three studies (75 reports) met the inclusion criteria. For RCTs, 33 and 11 studies had a low and high risk of bias respectively. For the remainder (n = 20) it was unclear. The non-randomised studies (n = 9) were low quality. There were 33 separate comparators. The most common were acupressure versus placebo (n = 12); steroid versus usual treatment (n = 7); ginger versus placebo (n = 6); ginger versus vitamin B6 (n = 6); and vitamin B6 versus placebo (n = 4). There was evidence that ginger, antihistamines, metoclopramide (mild disease) and vitamin B6 (mild to severe disease) are better than placebo. Diclectin^® [Duchesnay Inc.; doxylamine succinate (10 mg) plus pyridoxine hydrochloride (10 mg) slow release tablet] is more effective than placebo and ondansetron is more effective at reducing nausea than pyridoxine plus doxylamine. Diclectin before symptoms of NVP begin for women at high risk of severe NVP recurrence reduces risk of moderate/severe NVP compared with taking Diclectin once symptoms begin. Promethazine is as, and ondansetron is more, effective than metoclopramide for severe NVP/HG. I.v. fluids help correct dehydration and improve symptoms. Dextrose saline may be more effective at reducing nausea than normal saline. Transdermal clonidine patches may be effective for severe HG. Enteral feeding is effective but extreme method treatment for very severe symptoms. Day case management for moderate/severe symptoms is feasible, acceptable and as effective as inpatient care. For all other interventions and comparisons, evidence is unclear. The economic analysis was limited by lack of effectiveness data, but comparison of costs between treatments highlights the implications of different choices.

LIMITATIONS

The main limitations were the quantity and quality of the data available.

CONCLUSION

There was evidence of some improvement in symptoms for some treatments, but these data may not be transferable across disease severities. Methodologically sound and larger trials of the main therapies considered within the UK NHS are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013006642.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.