The protesters were callings for a delay to the modernisation of abortion legislation proposed by Health & Social Care.
About 30 members of Life For Both, formerly Both Lives Matter, congregated from 8.30am.
Spokesperson Jenny Hooper said: 'I am not here to say anybody is right or wrong to have an abortion. I'm here to say this law should make people equal. These propositions are going to completely categorise the unborn into disabled and non-disabled. Because of this, people will generally believe it is okay to abort a baby up until birth on the grounds of non-fatal conditions.'
'There should not be categories, they set a dangerous precedent and a worth value on life. HSC will not put a boundary definition on disability, because then they set a standard for what life is worth living. All lives are worth living.'
Deputies are due to discuss the reforms via Microsoft Teams during this month's States meeting, which got underway this morning.
LFB spokesperson Maria O'Brein said: 'We wanted to be here while the States conduct a meeting online. A silent protest is more powerful, we don't need to shout or scream. Pro-life is a gentle and compassionate cause, wherever you find a pro-life movement. Our core is very peaceful.'
'LFB has been in the offing since HSC published their policy letter in March. We have had very limited time to co-ordinate a response.'
Changes to the policy letter were proposed this week in a series of amendments by Deputy Andrea Dudley-Owen, Deputy Jane Stephens and Deputy Jonathan Le Tocq.
These addressed categorical ableist discrimination, women's mental welfare, consent and coercion, the need for evidence, foetal pain relief, gestational limits and conscientious objection.
'I was really pleased to see the amendments, these deputies have done a really good job. Their propositions are correcting the areas which the original policy letter neglected. The gravity of this issue is that people need to think about the society we want to live in.'
A letter was read sent by Alderney residents who have created a petition and wished to convey their support.
Father Bruce Barnes of the Guernsey Catholic Church said: 'We believe very much in the dignity of human life. It is precious, it should be respected and saved in all forms from conception to grave. We support women having an informed choice and a pathway to care.'