Mr Ansley said he could understand he position of his duty manager in taking such a conservative approach towards serving alcohol to a pregnant woman, given health warnings about the effects of intoxification and growing pressures from society and authorities to exercise host responsibility.
But he told the Herald the Sale of Liquor Act defined just two classes of "prohibited persons" to whom it was unlawful to serve alcohol - being minors and intoxicated people.
Although it was incumbent on liquor licence holders to pay special attention to pregnant patrons, to ensure they did not become intoxicated, that should not extend to refusing service in the first instance.
"I think there is a fundamental human right at play, that you do not discriminate on the basis of gender," he said.
"Women are the ones who get pregnant - they have the right to choose themselves about what are the health choices and the options they will take during the pregnancy."
Mr Ansley said he would remind all his managers of the extent and limits of their responsibilities under the Sale of Liquor Act, in terms of refusing service to prohibited persons, while also highlighting their obligations under the Human Rights Act "and giving them some stratgies about how to deal with situations where those two pieces of legislation collide."
"My position would be that prohibited persons - minors and intoxicated people - are sacrosanct but outside that we need to be very careful we don't impinge on people's rights."
He said his sympathy for Mrs Hayes, and the embarrassment she would have suffered last night, were highlighted by the fact that his own partner was at a similarly advanced stage of pregnancy.
"I have to say when I heard of this I reacted with a certain amount of horror," he confessed.
"Because I can imagine being in that situation on an anniversary date with my partner who is heavily pregnant but a very intelligent, smart, independent woman in the same way I am assuming Mrs Hayes is, and her reaction would be exactly the same."
Royal Australian and New Zealand College of Obstetricians and Gynaecologists spokeswoman Dr Emma Parry said that although the organsiation recommended avoiding alcohol in pregnancy, its guidance document on the issue stated that counselling woman about possible adverse effects was difficult.
At the same time, guidelines from Britain's National Health Service stated that women should be advised to avoid drinking in the first three months of pregnancy if possible, as that may be associated with an increased risk of miscarriage.
But the British document also states that although there there is uncertainty regarding a safe level of alcohol consumption in pregnancy, there is no harm to unborn babies if woman drink no more than one to two UK units of alcohol once or twice a week.
It states that one unit equals half a pint (236 millilitres) of ordinary strength lager or beer, or one 25 millilitre shot of spirits.
One small (125 mil) glass of wine is equal to 1.5 UK units.
Dr Parry, an Auckland obstetrician, said the job of doctors and midwives caring for pregnant women was to give them the best information available "but whether they take that advice is their decision."
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Earlier today, Mrs Hayes said she was was "completely flabbergasted and embarrassed" when a waitress denied her service.
"One glass of bubbles for a consenting non-intoxicated adult at at advanced state of pregnancy," she told the Herald earlier today.
"I do see both sides of the story but at the same time many women drink within the first three months of pregnancy without knowing they are pregnant and when the foetus is at its most vulnerable.
"I think it is very much a grey area and would be interested in what other bars do in this situation."
Mrs Hayes, who is 36.5 weeks pregnant, said the waitress initially thought she wanted a soda and tried to list options for those.
"I then pointed out to her the drink I would like from the menu; she went away and came back a few minutes later and said she thought she had misunderstood me and asked if I was pregnant.
"I said, yes, and she said she was uncomfortable serving pregnant women alcohol."
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