Pregnant teachers should not give up their dreams of school leadership because of motherhood. Instead, they could consider job sharing, says a leading female union official.
As Wales braces itself for a headteacher recruitment crisis, Heledd Hayes, education officer for the National Union of Teachers Cymru, said co-headships could be a realistic solution, although there could be some reluctance initially. But she said job shares had worked for classroom teachers.
"Part-time teachers tend to do a little more than half the work, which adds up, so pupils could benefit," said Dr Hayes.
In England, where a similar shortage is forcing schools to re-advertise headships, innovative solutions, including co-headship, have already been introduced. At least 30 schools have opted for co-headships, where two or more leaders share the post part-time.
Eight per cent of Wales's heads are expected to retire over the next five years, but unions are warning that younger teachers are increasingly unwilling to fill their shoes.
Women make up a third of secondary teachers, but only 16 per cent of heads are female. Expectant mothers sometimes leave teaching to find a job with more flexible hours, so a shared headship could prove an attractive option.
The Assembly government has contracted York Consulting in Leeds to study the job needs and aspirations of potential heads. The research will examine the barriers to filling headships and the future demand for Welsh-medium heads.
Dr Hayes said the high number of women completing the national professional qualification for headship was encouraging, but both sexes seemed reluctant to apply for the top posts.
"There are many reasons for this," she said, "but for some it does seem to be the stress of the job. It does fill your life. There are secondary heads who are still at work at eight or nine o'clock at night."
Anna Brychan, director of the National Association of Head Teachers Cymru, said teachers in larger schools were finding the poor work-life balance and bureaucracy of headship unappealing.
"There has been a willingness to look at other sorts of leadership, but that must be done with proper consideration of the terms and conditions for heads," she said.
Some schools were already trying different forms of leadership out of necessity, she said: "I believe there are informal situations where heads are about to retire and have shared the responsibility with a younger person. It means they can pass on their experience and step down from leadership softly."
Gareth Jones, secretary of the Association of School and College Leaders Cymru, said schools should consider co-headship where the stress of the job was a problem. But he believed there was no single explanation for the general reluctance to strive for headship in Wales.
John Howson, a teacher recruitment expert and managing director of Education Data Surveys, which is owned by TSL Education, proprietors of The TES, suggested that six-figure salaries for heads in England were putting pressure on the Welsh market.
"There is concern about the ripple effect, which might leave some teachers asking themselves if they want a relatively nice school in Newport or a slightly more challenging one in London with higher pay," he said.
In Wales, a more common alternative to the one-school, one-head model has been executive headship or federalisation, where one person is head of more than one school. Such schools may or may not share governing bodies.