Most secondary school teachers think pupils should be told how to get an abortion, a poll suggests.
Sex education varies across the country
Under current policy, the topic is optional and schools are advised to respect the religious sensitivities of children and their parents.
A survey of 700 teachers in England and Wales, for the Times Educational Supplement, found 69% backed lessons on terminating unwanted pregnancies.
More than 75% said parents should be told if their child wanted an abortion.
Almost all (98%) favoured teaching about contraception in class.
The survey also showed the majority of teachers (74%) would be happy to tell children it was acceptable to be gay.
Britain has the highest teenage pregnancy rate in western Europe and the government has said it wants to halve the pregnancy rate of people under the age of 18 by 2010.
One in every 10 babies born in England is to a teenage mother.
The editor of the TES, Bob Doe, told BBC News that while most teachers were happy to give explicit information in sex education lessons, they were "very uncomfortable" about the idea of a child seeking an abortion without her parents' knowledge.
"It is the government's intention that schools should become the places where all child welfare policies are delivered in future.
"Schools are becoming implicated in a controversy about whether or not children should be given an abortion without their parents' knowledge.
"The law gives children the right to confidentiality in medical matters and that right is above a parent's right to know."
Catherine Lane teaches sex education at a Roman Catholic all-girls school in Dorset.
She says girls are taught about contraception and terminations in science and in sex education lessons and also in the context of religious education.
She said if a girl told her she was pregnant and did not know what to do, she would not advise her directly but would refer her on through the school to an anti-abortion charity offering counselling, such as Life.
"Girls have a right in their medical context to confidentiality. Schools are in a minefield here. We are teachers, not doctors. I am not qualified to give someone advice about what they should do.
"In sex education lessons I teach them the facts and the Catholic church's teaching which is what their parents expect and why they sent them here."