Women are less likely than men to receive life-saving CPR in a public place if they suffer a cardiac arrest, research suggests.
Dutch scientists found 73 per cent of men who had public cardiac arrests received CPR from a bystander - but only 68 per cent of women did.
Fears touching a woman's chest may be seen as sexual harassment may put people off from helping to restart their heart, scientists say.
An expert commenting on the study also claimed that bystanders may be scared of hurting 'frail' women by performing CPR.
The researchers warned people are less likely to realise the seriousness of a woman's condition and may be slower to realise they need help.
This may lead to delays in calling the emergency services, hindering the survival chances of female patients.
Researchers from the University of Amsterdam analysed 5,717 out-of-hospital cardiac arrests in one part of the Netherlands between 2006 and 2012.
They found around 12.5 per cent of women who were resuscitated survived to be discharged from hospital, compared to 20 per cent of men.
The researchers suggested this was most likely to be down to delays in calling an ambulance and starting CPR on women.
Lead author Dr Hanno Tan said: "Given the short window available to save the life of the patient, every minute in this early phase counts."
"Help, if only a call to the emergency number by a lay person, is crucial.
People may be less aware that cardiac arrest can occur as often in women as in men, and the women themselves may not recognise the urgency of their symptoms.
Women may have symptoms of an impending heart attack that are less easy to interpret, such as fatigue, fainting, vomiting and neck or jaw pain."
He added that men are more likely to report typical complaints such as chest pain.
Dr Sarah Perman, an assistant professor of Emergency Medicine at the University of Colorado School of Medicine, offered another explanation for the finding.
She said similar studies have shown that there is "over-sexualisation of women's bodies". However, she was not involved in the study.
Dr Perman added many "feel hesitant to provide CPR if there is a notion they are doing something incorrect that was perceived to be sexual assault or harassment".
She said people are more likely to think a woman has just fainted, and said many have a "fear of causing injury because women are more frail".
The research was published in the European Heart Journal.
Figures from St John in NZ show that fewer than one in six people survived cardiac arrests that happened outside hospitals in 2017.
St John has a free CPR app with instructions on how to use an AED and perform CPR.
You can also learn to perform CPR through a free course with St John.