NEW YORK — The United States lags far behind virtually all wealthy countries with regard to family-oriented workplace policies such as maternity leave, paid sick days and support for breast-feeding, a new study by Harvard and McGill University researchers says.

The new data comes as politicians and lobbyists wrangle over whether to scale back the existing federal law providing unpaid family leaves or to push new legislation allowing paid leaves.

The study, officially being issued Thursday, says workplace policies for families in the United States are weaker than those of all high-income countries and many middle- and low-income countries. Notably, it says the U.S. is one of only five countries out of 173 in the survey that does not guarantee some form of paid maternity leave; the others are Lesotho, Liberia, Swaziland and Papua New Guinea.

“More countries are providing the workplace protections that millions of Americans can only dream of,” said the study’s lead author, Jody Heymann, founder of the Harvard-based Project on Global Working Families and director of McGill’s Institute for Health and Social Policy.

Among the study’s findings:

• Fathers are granted paid paternity leave or paid parental leave in 65 countries, including 31 offering at least 14 weeks of paid leave. The U.S. guarantees fathers no such paid leaves.

• At least 107 countries protect working women’s right to breast-feed; the breaks are paid in at least 73 of them. The U.S. does not have federal legislation guaranteeing the right to breast-feed at work.

• At least 145 countries provide paid sick days, with 127 providing a week or more annually. The U.S. provides unpaid leave through the Family and Medical Leave Act, which does not cover all workers; there is no federal law providing for paid sick days.

• At least 134 countries have laws setting the maximum length of the work week. The U.S. does not have a maximum work week length or a limit on mandatory overtime per week.

According to the study, the U.S. fares comparatively well in some areas — such as guaranteeing significantly higher pay for overtime work and ensuring the right to work for all racial and ethnic groups, regardless of gender, age or disability.