Ealing Council was the first in the country to create a 100-metre protest-free "buffer zone" outside a Marie Stopes clinic in the west London borough following protests.
Christian mother Alina Dulgheriu, of the Be Here For Me campaign argued the ban was an unlawful interference with the protesters' rights under the European Convention on Human Rights - including the right to freedom of expression.
But the case was dismissed on Monday by Mr Justice Turner, who found the ban does interfere with activists' rights but said the council was "entitled" to conclude it was a "necessary step in a democratic society".
The judge added: "There was substantial evidence that a very considerable number of users of the clinic reasonably felt that their privacy was being very seriously invaded at a time and place when they were most vulnerable and sensitive to uninvited attention.
"It also follows that, in this regard, I am also satisfied that the defendant (council) was entitled to conclude that the effect of the activities of the protesters was likely to make such activities unreasonable and justified the restrictions imposed."
The public spaces protection order (PSPO) came into force in April after reports of "intimidation, harassment and distress" for women using the facility on Mattock Lane.
Clinical operations manager John Hansen-Brevetti said women had been told that the ghost of their foetus would haunt them, had been told "mummy, mummy, don't kill me", had holy water thrown on them and rosary beads thrust at them.
Ms Dulgheriu, 34, said she was offered financial, practical and moral help, as well as accommodation, and now had a "beautiful" six-year-old daughter.
In a statement following the ruling, she said she is looking into options to challenge the judge's decision.
She added: "I am saddened and shocked that the court has upheld a PSPO that prevents good people giving help to mothers who desperately want it.
"I am devastated for those women that, since the introduction of the Ealing PSPO, have not been able to access the loving help that I did.
"I feel desperately sorry for the vigil members who since the move to create this PSPO have been consistently subject to abuse on the street and slander online."
The judge said his ruling does not give the "green light" to local authorities to impose PSPOs around abortion clinics and that each case must be decided on its own facts.
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.