The first execution of a female inmate in Georgia since World War II was delayed for several hours on Monday evening and then ultimately postponed due to an issue with the lethal injection drugs, authorities said.

The execution of Kelly Renee Gissendaner, scheduled for Monday at 7 p.m., was called off shortly after 11 p.m. Many had waited for word from the U.S. Supreme Court, which had been asked by Gissendaner’s attorneys to halt the execution and had not responded to the request by 11 p.m.

But corrections officials said that issues with the drug, rather than waiting on any court orders, prompted the postponement.

“Prior to the execution, the drugs were sent to an independent lab for testing of potency,” the Georgia Department of Correction said in a statement. “The drugs fell within the acceptable testing limits. Within the hours leading up to the scheduled execution, the execution team performed the necessary checks. At that time, the drugs appeared cloudy.”

After consulting with a pharmacist, the execution was delayed “in an abundance of caution,” the department said.

This is the second postponement of Gissendaner’s execution in less than a week. The Monday night execution was set to occur five days after her lethal injection was postponed due to a winter storm.

Gissendaner was convicted of murdering her husband nearly two decades ago. Her attorneys filed an emergency stay request with the state parole board, which denied the clemency bid, while religious groups argued that her spiritual changes warranted stopping the execution. An appeals court on Monday rejected her stay request, while Gissendaner also asked the U.S. Supreme Court to act.

Yet the postponement did not relate to her appeals or the protests of religious groups. Instead, it stemmed from an issue with a lethal injection drug, echoing other problems that have cropped up across the country.

shortage of lethal injection drugs has caused the dwindling number of states still carrying out executions to scramble and improvise. Three high-profile executions that seemed to go awry last year drew additional scrutiny to this practice. The three-drug combination that had been typical has been replaced by a patchwork system, and the U.S. Supreme Court will hear a case involving lethal injection this spring after justices questioned one of the drugs adopted in recent years by Oklahoma and Florida for executions.

If Gissendaner’s execution at the state prison in Jackson is eventually carried out, it will be a rarity for the state as well as the country. Just a handful of women have been executed during the modern era of the death penalty, and Georgia has not put a female inmate to death since 1945.

Part of this has to do with the realities of crime in the United States. Men account for a little less than half of the population but are arrested far more often than women; 6.6 million men were arrested at least once in 2013, compared with 2.4 million women that year, according to the FBI’s annual report on crime in the country.

Women account for about 7 percent of the state or federal prison population, a number that has remained relatively static over the last decade, Justice Department figures show. This also plays out on death row: Just 2 percent of the 2,900 people sitting on death row at the end of 2013 were female, the Bureau of Justice Statistics found.

The last inmate put to death in the United States was Lisa Coleman, who was executed by Texas in September. Coleman was just the 15th woman put to death since the U.S. Supreme Court reinstated the death penalty in 1976, which means women made up about 1 percent of the 1,402 executions that have occurred over that period.

Georgia has not executed a female inmate since Lena Baker became the only woman put to death on the state’s electric chair on March 5, 1945. Baker, a black maid who was put to death for killing a white man, had said that she shot him in self-defense. She was found guilty by a jury of a dozen white men — “hardly a jury of her peers,” as Rep. Sanford Bishop Jr. (D-Ga.) put it in 2011 when he posthumously honored her in the congressional record. The Georgia parole board posthumously pardoned Baker in 2005, six decades after she was executed, declaring in its annual report that “it was a grievous error to deny clemency” to Baker.

A decade later, Gissendaner, 46, is the only woman currently sitting on Georgia’s death row. She was scheduled to be executed last week, but with a winter storm looming and portions of the state facing several inches of snow, the Georgia Department of Corrections rescheduled the execution for Monday night.

Gissendaner was convicted and sentenced to death in 1998. She convinced Gregory Owen, her boyfriend, to kill Douglas Gissendaner, her husband, according to the office of Sam Olens, Georgia’s attorney general.

Her attorneys filed an emergency stay request Monday morning with the state pardon and parole board, asking for a 90-day postponement to let the board hear from additional witnesses vouching for her clemency requests. In particular, the stay application says the board needs to hear from “many vital witnesses” who work for the Georgia Department of Corrections.

The Georgia Board of Pardons and Paroles declined this new stay request on Monday. The board is the only entity in the state that can commute a death sentence or change it to life in prison or life without parole. The board first denied her request last week, a day before her previously-scheduled execution, and said Monday it would let that decision stand.

When the parole board heard from people testifying that Gissendaner should be granted clemency last month, they did not hear from people who work for the corrections department because her attorneys say there was uncertainty regarding whether these employees were allowed to testify.

“This is an exceptional case requiring exceptional and immediate action,” Susan Casey and Lindsay Bennett, Gissendaner’s attorneys, said in a statement Monday. “Kelly’s case cries out for the mercy power vested in the Board.”

In the emergency request, Gissendaner’s attorneys point out that she was sentenced to death while Owen, who pleaded guilty and testified against Gissendaner, was sentenced to life in prison with a possibility for parole in 2023.

The stay request also noted that Kayla and Dakota, Kelly and Douglas Gissendaner’s children, do not want their mother put to death for the murder; they wrote letters to the parole board emphasizing that their mother had changed and become, as Kayla put it, “a woman full of love and compassion.”

The U.S. Court of Appeals for the 11th Circuit on Monday also denied her stay request. Her filing noted that the Supreme Court is going to consider lethal injection soon, but the appeals court ruled that the coming decision in that case would not affect Gissendaner. Georgia uses an injection of one drugpentobarbital — to kill inmates. She has also petitioned the U.S. Supreme Court to stay the execution, but the court had not responded by Monday night.

Theologians and religious leaders have called on the state to halt the execution, pointing to Gissendaner’s work completing a theology studies program while in prison.

Bishop Robert Wright of the Episcopal Diocese of Atlanta, who has urged Georgia Gov. Nathan Deal (R) to halt all executions in the state, was among the hundreds who signed a letter asking authorities to commute Gissendaner’s death sentence and change her punishment to life in prison without parole. The letter argued that Gissendaner has “experienced a profound spiritual transformation” during her 18 years behind bars.

“While we can recognize and deeply sympathize with the profound grief of the parents and extended family of Doug Gissendaner, we also must attend to the ongoing grief of Kelly’s children who have already lost a father and who will experience immeasurable pain in losing another parent,” the letter states. “In solidarity with their pleas for their mother’s life, in keeping with the value of mercy, and in hope for the good works Kelly could perform during a sentence of life without parole, we ask that Kelly’s life be spared.”

Gissendaner was scheduled to be the ninth person executed so far this year in the U.S.

The meal she ate on Monday, believed at the time to be potentially her final meal, included cornbread, two cheeseburgers, french fries, cherry vanilla ice cream, popcorn, salad and lemonade, according to the Department of Corrections.

This post has been updated repeatedly. First published: 3:19 p.m.