A leading sexual health charity is warning against the closure of all Lincolnshire's family planning clinics.
The move is one measure being considered by local NHS managers who are trying to balance the books.
But the Family Planning Association (FPA) said women across the county would be disadvantaged and the move would be a "highly retrograde" step.
Health bosses in Lincolnshire insist no action will be taken until staff and the public have been consulted.
Health bosses in Lincolnshire want to avoid a predicted monthly overspend of more than £2m.
The FPA said the clinics offered an unrivalled source of expertise on contraception, cervical screening and pregnancy testing, and could provide other services like testing for infections and counselling for sexual problems.
Melissa Dear, of the FPA, said the clinics were indispensable to the 2.7 million women in England who attended every year.
"General practice is a valued partner in contraceptive provision, but it does not duplicate the services offered by family planning clinics," she added.
Proposals 'not developed'
"Many practices do not provide all 14 of the different contraceptive methods and rely on referring women to clinics for the more specialist methods."
Teresa Williams, a mother of three who highlighted the problem, said: "With teenage pregnancies and STD at an all time high this is a dangerous move.
"Where will teenagers go for professional and confidential advice about all the problems and complexities associated with maturing sexuality?"
In a statement East Lincolnshire Primary Care Trust - which oversees Lincolnshire's family planning services - said: "Staff are being consulted about proposals that are being developed to make changes to the family planning service in Lincolnshire.
"These proposals are not fully developed and we would not wish to comment on specific details until they are fully developed.
"The proposals will be subject to a wide public consultation and no changes will be made until that consultation is completed. "