Introduction

1. Background

Nausea and vomiting in pregnancy

Nausea and vomiting in pregnancy (NVP) is a common condition, affecting approximately 80% of pregnant women. Symptoms typically improve or resolve by weeks 16 to 20, though for some women it can last longer. Hyperemesis Gravidarum (HG) is a severe form of NVP, occurring in 0.3% to 3.6% of pregnant women, which in some cases can last until the baby is born.

HG is characterised by persistent and intense nausea and/or vomiting that significantly interferes with normal eating and drinking. This can lead to complications such as dehydration, weight loss and low blood pressure. In some cases, it can require hospital treatment.

A 2021 study published in Obstetric Medicine found that approximately 5% of women with HG ended a wanted pregnancy due to the severity of their symptoms. Additionally, around 52% reported considering termination. The study also revealed significant mental health impacts: 25.5% of respondents occasionally experienced suicidal thoughts, while 6.6% reported frequent suicidal ideation.

Xonvea

Xonvea (a combination of doxylamine and pyridoxine) is a licensed medicine for the treatment of NVP in women who do not respond to conservative management. It is the only medication licensed in the UK for this indication.

In June 2019, NICE published an evidence summary on Xonvea. This has since been updated and incorporated into NICE guideline NG201: Antenatal care, where it is listed among a number of pharmacological options for managing NVP.

NICE states in its guidelines that the evidence for Xonvea providing symptom relief compared to placebo is of “low or very low quality.” However, unlike alternatives with stronger efficacy data—such as Metoclopramide and Ondansetron—it is not associated with an increased risk of birth defects.

A survey conducted by Pregnancy Sickness Support in April 2025 found that 83% of women who had experienced NVP and been offered Xonvea had found it effective. Among these, 87% considered it more effective than other medications they had tried.

The Royal College of Obstetricians and Gynaecologists currently includes Xonvea among the recommended first-line antiemetic options for managing NVP, alongside other antihistamines and phenothiazines used off-label.

Access to Xonvea in Wales

Health boards in Wales are required to make medicines recommended by NICE available to patients within 60 days. However, Xonvea has not undergone a full technology appraisal by NICE and so is not subject to this requirement. In cases where a medicine has not been appraised by NICE, the All Wales Medicines Strategy Group (AWMSG) assesses whether to make a medicine routinely available in NHS Wales.

In 2019, AWMSG published advice not to recommend the routine use of Xonvea in NHS Wales, citing insufficient evidence of cost-effectiveness and clinical benefit compared with existing treatments. The decision was based on uncertainties in the economic model, such as hospitalisation rates, and the absence of robust comparative data with alternative therapies. This recommendation was subsequently ratified by the Welsh Government.

The Scottish Medicines Consortium reached a similar conclusion to AWMSG in 2019, advising that Xonvea should not be made routinely available in NHS Scotland. In England, Xonvea is available in some areas, but access is inconsistent. The UK Government has acknowledged this variation and stated it will review prescribing practices and set clearer expectations for clinicians to ensure more equitable access.

In August 2025, it was reported that AWMSG had been engaging with Xonvea’s manufacturer and that it was actively exploring options to improve patient access to the treatment in Wales.

2. Welsh Government action

The Welsh Government response to this petition states that the AWMSG appraisal undertaken in 2019 remains the most comprehensive evaluation of Xonvea to date. It notes that AWMSG only conducts reappraisals when new evidence or price changes could affect cost-effectiveness, but in this case there has been little or no new evidence since 2019. The response also notes that AWMSG invited the manufacturer to provide an updated submission but no additional information was supplied, though engagement is ongoing.

The response goes on to state that while AWMSG does not recommend Xonvea for routine use, health boards can include it in local formularies under certain circumstances, and clinicians may prescribe it when other treatments for NVP are unsuccessful. According to the response, between January and July 2025, more than 1,140 Xonvea prescriptions were issued in the community.

3.     Welsh Parliament action

The Senedd has not considered patient access to Xonvea or the broader management of NVP to date.