NASHVILLE (AP) — Officials with the Tennessee Department of Health say 85 percent of all maternity deaths in 2017 could have been prevented, with substance abuse being determined as the leading contribution in those deaths.

The agency issued the report on Tuesday after the Tennessee General Assembly in 2016 passed the Maternal Mortality Review and Prevention Act. The law created a review panel to look over maternal deaths and offer prevention recommendations.

According to the 59-page report, the panel verified 78 deaths in 2017 were pregnancy-associated despite 98 deaths flagged as such. Tennessee's pregnancy-associated mortality ratio would have been 26 percent higher if not for the review panel.

The majority of deaths reviewed occurred 43 days to one year after pregnancy, while the remaining deaths occurred during pregnancy or soon after pregnancy.