Amendments to the IVF law, which open the door for embryo testing, have not yet been signed by President George Vella who is understood to be uncomfortable with the reform.
Sources said the delay, two weeks since the amendments were approved in parliament, is starting to make members of the government anxious.
While such delays have been experienced before, sources said they were growing concerned that Vella would not sign the reform and instead leave it to his stand-in when he is next overseas.
Vella is understood to be travelling out of the country in August.
Questions have been sent to the Office of the President.
The IVF reform was a flagship proposal of the Labour Party during the March election campaign, with Prime Minister Robert Abela promising to deliver it within 100 days of being returned to office.
The new IVF law will allow genetic testing prior to implantation to enable doctors to spot certain conditions such as Huntingtons' Disease before the embryo is implanted in the womb.
The amendments were approved by parliament on July 6, gaining support from both parties with 66 votes in favour and three against.
Vella is known to have privately expressed reservations about the amendments, which conservative opponents feel violates their pro-life beliefs.
Earlier this month the president was evasive over whether he would personally sign the amendments, saying only "the law will be signed."
Asked if he will personally be signing it, Vella refused to give a straight answer.
University pro-rector Frank Bezzina was appointed by the government as acting president last month, in what was seen as a move to ensure the president's office would sign off on the law if Vella was reluctant to do so.
Until the reform is signed, it cannot start being implemented.
Meanwhile, an announcement that the reform was signed was published in the latest online issue of the Government Gazette on July 12.
Announcement removed from Government Gazette
The announcement however was removed from the digital edition soon after.
The matter was flagged on Wednesday by PN MP Ivan Bartolo.
Department of information head Paul Azzopardi told Times of Malta that this was an error that had been rectified.
He added that the error had not appeared in the printed version of the gazette which is the official and legally binding version of the document.
The new genetic testing reform has had a bumpy road to implementation.
The Nationalist Party had initially opposed pre-implantation genetic testing and later argued that prospective parents should have a choice.
Its proposal to offer the alternative of polar body testing - which does not involve testing of embryos - was taken on board by the government.
MPs Adrian Delia, Alex Borg, and Ivan Bartolo voted against the reform, which had made conservative members of the Opposition uncomfortable.
PN MPs Carm Mifsud Bonnici, Chris Said, and Jerome Caruana Cilia were not present for the vote.