London, Oct 7 (IANS) Twenty percent of Britons aged 18 to 25 think an umbilical cord is a musical note, being clueless about it actually connecting a baby to its mother’s womb.

And 21 percent of the 2,000 respondents believed pregnancy lasts for 12 months, rather than nine, according to a survey.

One in 10 thinks that the placenta, which nourishes the unborn baby, is a vegetable. Twelve percent believe a caesarean section is a religious cult, rather than a surgical procedure for delivering a baby.

The survey also revealed that more than half of young adults would expect a baby to be walking and talking within the first year, when it is more normal for a child to start talking at the age of two and walking at some point after 12 months, the Daily Mail reported.

Eight percent believe that drinking tea or coffee will influence the colour of an unborn child’s hair, and one in 10 thinks that eating red meat raises the likelihood of giving birth to a boy.

Many of these confused 20 somethings may find they have to learn quickly – because more than half said 28 was the best age to start a family.

A similar proportion also believes that two children is the optimum number of offspring for the ‘perfect’ family size.

Relationship expert Tracey Cox said: ‘Given the amount of information available around this subject both at school, amongst peers and from families, it’s astonishing how innocent and gullible young adults are on the subject of babies, parenting and childbirth.’

New mother Joanne Saunders, 32, from Sevenoaks, Kent, said: ‘It’s amazing how much you learn being a new mum, but I knew what an umbilical cord was and how long a normal pregnancy lasts when I was at school.’

‘It’s absolutely terrifying that many of these people are completely unaware of the basics of human biology,’ she said.