"As with abortion, Catholics cannot use in vitro -- among other reasons because the cost of the birth of a single human person is the destruction of other unborn children," the bishops' conference said.
"The moral responsibility for what has occurred lies with the legislators who supported and approved this law, and with managers of health service institutions where this method is used," the bishops said.
The bishops' comments came after Komorowski signed the Law on Treating Infertility in one of the last acts of his presidency following his defeat in May 24 elections. Voters selected Andrzej Duda, a conservative Catholic, over Komorowski as Poland's next head of state.
In a July 22 statement, the bishops said they were "deeply disappointed and pained" by the law, explaining that Catholic teaching rejected all techniques of artificial insemination that "replaced the marital act."
Archbishop Henryk Hoser of Warsaw-Praga, chairman of the Polish church's bioethics commission, deplored the signing of the "extremely liberal and permissive" law, calling it a "black day for Polish parliamentarism." He accused Komorowski of ignoring the church's "biological, medical, legal, psychological and ethical arguments."
"Far from regulating and restricting anything, this law opens all doors to every possible abuse of human life," Archbishop Hoser told Poland's Catholic information agency, KAI.
"It's a bad law, which will have very negative social and biological effects and repercussions for the future health of Poles. As soon as possible, we'll support changes to make it conform to elementary human rights," he said.
A bill to permit state funding of IVF, which had been unregulated in Poland, was tabled in 2008 by the liberal government of former Prime Minister Donald Tusk after the bishops warned in a letter to government leaders that the practice resembled Nazi-era eugenics.
Komorowski said in a July 22 statement he believed the law was favoured "by a huge majority of Poles," explaining that he had no wish to be "a president of human consciences" when Polish citizens had "contrasting views and outlooks and different religious involvements."
The law is the latest of several blows to the Catholic Church from the Polish parliament, which in April ratified a controversial Council of Europe convention combating violence against women, despite vigorous church opposition, and passed a law July 23 to allow sex change procedures.
In their statement, the bishops said there had been "an organized conspiracy, embracing international institutions, foundations and associations" to spread IVF worldwide, and urged childless couples to use "morally reasonable infertility treatment methods" or adopt orphans.
Poland's Health Ministry said in a July 2014 report that 11,789 couples had requested IVF treatment if a law legalizing the procedure was passed. Nearly 8,700 of the couples had been accepted for the procedure.
More than three-quarters of Poles said they favoured allowing IVF, with 17 per cent against, in a July 3 survey by Warsaw's government-run Public Opinion Research Center. In a commentary accompanying the release of the results, the centre said the views of Poles had remained virtually unchanged for 20 years.