Pregnant women have been urged to ensure that they are protected against measles as numbers of people with the highly infectious illness continues to rise.
Figures from Public Health England (PHE) show that from the start of the year until July 22, there were 781 laboratory confirmed measles cases in England.
Comparatively, there were 274 cases in the whole of 2017.
The most cases have been reported in London, followed by the South East, South West, West Midlands and Yorkshire and Humberside.
Becoming infected with measles during pregnancy can increase the risk of miscarriage or stillbirth.
It can also lead to babies being born prematurely or having a low birth weight.
One NHS trust has issued guidance to pregnant women to make sure they are protected as cases continue to rise across England.
Janet Cairns, head of midwifery at Hull and East Yorkshire Hospitals NHS Trust, said: “Now is the right time to check if you and your family are vaccinated against the risk of measles.
“GPs can advise, and give vaccines to anyone who has not been adequately protected. Two doses of the MMR vaccine can prevent more than 95% of cases of measles, mumps and rubella.
“If you are pregnant and have been in contact with someone with measles, which is infectious from a few days before the rash appears, please contact your GP or midwife, who can request a blood test to check whether you are immune.”
According to NHS guidance, pregnant women who think they have come into contact with someone with measles and know they are not immune, should see their GP as soon as possible.
Many new cases in Britain have been linked to a European outbreak, prompting health officials to call on travellers to make sure they are vaccinated.
Earlier this year, PHE urged young adults and teenagers planning to go to Europe during the summer to check they are vaccinated against measles.
It called on would-be travellers to check they have had their MMR jabs.
Uptake of the MMR vaccine fell heavily in the late 1990s following the publication of research by Andrew Wakefield which suggested a possible link between the inoculation and autism.
Experts have widely discredited his study and he was struck off the medical register in 2010.
While vaccine uptake levels in the UK in young children are currently very high, coverage levels dipped to a low of 80% in 2003.
This means there are significant numbers of unprotected teenagers and young adults who could contract measles.
Measles is a highly infectious viral illness and can be deadly in some cases.