The gestation of primary care groups has been long and eventful.

First we wondered whether it was a phantom pregnancy based on the rhetoric of the 1997 Primary Care Act. It took the morning sickness of a new white paper to convince us that the ghastly feeling in our belly was the early sign of something new and exciting - not something we'd eaten.

We are still not sure how we are supposed to relate to PCGs. What sort of problems and challenges will they face in their first year? They will need to answer some basic questions before we can tell whether they are growing into vibrant, healthy, vigorous... what? What are they meant to grow into? General Practice plc? Primary care trusts? Health maintenance organisations?

The first question concerns the tasks facing PCGs as they evolve: what are they actually supposed to do?

The second is how they relate to health authorities: are HAs PCGs' parents or their nannies? Parents retain some responsibility for their children, but nannies help their charges become independent - before withdrawing gracefully.

The third question is how PCGs will work with their siblings, and the clinicians within them. Will they become corporate and manage to collaborate on all their tasks? Or will there be ferocious sibling rivalry?

The fourth question mark is over PCGs' external relationships. How will they link to the acute sector? Can they learn to speak the same language as local authorities? Will local populations help or hinder their progress?

In answer to the first question, it is becoming clear that PCG commissioning has been relegated; PCGs' key task will be to look at local provision of primary and community services.

It is worth comparing the previous government's commissioning groups and total-purchasing pilots, which also concentrated on improving community and primary care services rather than procuring acute services.

This may partly have been because community services affected GPs' patients more directly, so changes could be seen more quickly.

But it may also have reflected their perceived lack of progress in changing acute services.

Whatever the reason, their activity anticipated PCGs and the government's expressed intention to focus on service provision in the new organisations.

This focus will be helpful to emerging PCGs as it will bring together clinical professionals based in the community, and help reinforce the concept of corporate clinical responsibility that makes up clinical governance.

Commissioning will have to wait until the PCGs' relationship with HAs is sorted out.

The second challenge - developing an effective working relationship between HAs and PCGs - is likely to preoccupy most minds over the next 12 months. To HAs it seems perverse to devolve so much power to clinically dominated PCGs while retaining responsibility for their mistakes; for advancing PCGs it feels frustrating to have HAs checking every aspect of their activity.

Those which succeed will recognise that trust is a prerequisite for progress, and that trust cannot develop without some risk and suspension of disbelief - which allow fledgling organisations to gain the self-confidence to act responsibly in an adult world. As long as expectations remain low and based on mistrust, progress is unlikely.

The issue of trust extends to professionals in PCGs, too; the tradition of inter-professional tribalism is long, and old rivalries underlie issues such as GPs' anxieties about patient poaching, or district nurses' suspicions of health visitors (and vice versa), to say nothing of the relationship between doctors and nurses.

These tensions will need to be reduced if PCGs are to become workable and if clinicians are to shift the focus of their allegiance from old professional groupings to the new, jointly owned organisation, angled as it is towards delivering care to local people.

Losing their professional identity entirely would be unhelpful - just as ignoring the distinctions between France and Italy would reduce the variety and plurality of Europe. But subsuming some of those identities into the common market of the larger entity is likely to bring benefit to all concerned, including PCG clients.

The fourth challenge - forging links with the outside world - is compounded by the need to do so in parallel with all the other activities.

In reality, internal nuts and bolts may need to be sorted out before external links can be tackled. Any links formed in the first year may be tenuous and symbolic at best. Having a social services presence on the board may signal important changes to the way we think about healthcare, as does the lay member's presence. But will they have the patience to wait while the links and hierarchies inside the immediate NHS family are fudged and argued and finally sorted into a form that allows the PCG to function smoothly and effectively?

Which brings us back to our original question: what will PCGs be when they grow up? Like any proud relatives, we can only hope for a fulfilling future. We may have aspirations for them to deliver all health services, or for them to become part of a reformed local authority system. We may see them getting larger and larger until they resemble acute trusts in the community, or we may want them to be small and flexible, ducking and weaving in response to their patients' and clients' needs.

Whatever their ultimate destiny, we look on fondly, and a little nervously, as they start their journey through life on April Fool's Day, and bid them bon voyage.