The government has changed its advice on swine flu in an attempt to defuse a row over its conflicting messages to pregnant women and those trying to conceive.

Amid increasing concern over the impact of swine flu on expectant women, the Department of Health has posted a new document on its website reiterating previously issued advice. It has also stressed that it is no longer telling women to delay conception.

Today, a DoH spokeswoman admitted that its previous guidance to those trying to conceive had been based on predictions for a pandemic involving bird flu, a more serious infection. She said the advice had now been "refined to reflect current circumstances".

She denied that the DoH advice to expectant mothers – which says they should not alter their behaviour but should "avoid crowds and unnecessary travel" – was conflicting.

"For most pregnant women the advice to wash your hands and look after yourself is sufficient but if you are particularly concerned, you can perhaps look at not going to crowded places or undertaking unnecessary journeys."

A statement from the DoH stressed that swine flu was mild in most cases. It added: "We advise everybody to plan their pregnancy carefully – we are not advising women not to conceive. Mums-to-be are more vulnerable to any type of flu. It is particularly important that anyone who has existing health problems and is thinking about starting a family should talk to their GP first, as they normally would."

The DoH was forced into a clarification after women appeared to be given conflicting advice.

The National Childbirth Trust advised women to consider delaying pregnancy until the pandemic had passed. It was accused of scaremongering but said it had only taken advice from the DoH website.

It was also reported that the Royal College of Midwives (RCM) and the Royal College of Obstetricians and Gynaecologists (RCOG) were advising pregnant women to avoid rush hour, stay indoors and restrict the movement of other children so to avoid bringing the virus home.

Today, the RCM/RCOG sought to distance themselves from advice about expectant mothers avoiding the rush hour or staying indoors. But, in comments that deepened the sense of confusion, they said pregnant women should avoid crowded places "wherever possible".

Concerns over expectant women were heightened after a woman with swine flu died last week shortly after giving birth prematurely. Named by her brother as Ruptara Miah, 39, she died in London's Whipps Cross hospital. Her newborn baby is reported to be very ill. A total of 29 people have so far died from swine flu.

Today, Dr Boon Lim, of the RCOG, said he disagreed with previous comments from the RCM for pregnant women to avoid the rush hour. Lim said: "If people go to work on the tube, they can't not go to work on the tube. They can take precautions to limit the spread but if they do not have the infection they should not stay at home." He said there was no need for parents to avoid taking children to play groups. "By all means follow sensible hygiene measures but do not change your lifestyle."

Belinda Phipps, director of the NCT, said: "Following the death of a pregnant woman on Friday we brought together in a Q&A all the disparate bits of advice out there. Since then, the DoH has changed their minds and said what they were saying about [delaying] conception wasn't sensible at all … the furore has been quite a good thing because it has caused them to look again at what they are saying."

However, there were few signs last night that the issue had become clear. A poll on Netmums, a parenting website, found that 30% of respondents were "really worried" about swine flu. The poll found that 48% of the 3,446 respondents were "concerned, although I know most people who get it don't suffer much and I generally think we'll be ok", while 18% were unconcerned.