ST. LOUIS — Missouri said Friday it is investigating the St. Louis Planned Parenthood office for “multiple” failed abortions, revealing for the first time why it is holding up the Central West End clinic’s license.

The state alleged in a statement on Friday that women remained pregnant after the St. Louis clinic performed abortions on them.

But a Planned Parenthood official called the state’s announcement “fear mongering” and a “diversionary tactic” that shows it “is treating Planned Parenthood differently in the inspection process.”

“The state continues to hold our license hostage, creating worry and uncertainty for our patients,” Dr. Colleen McNicholas, obstetrician-gynecologist at the St. Louis location, said in a statement.

The disclosure of the nature of the state’s investigation comes as Planned Parenthood and the state await a St. Louis judge’s ruling in Planned Parenthood’s lawsuit alleging the state had illegally refused to renew the St. Louis abortion clinic’s yearly license until the state could complete an investigation into an unspecified patient complaint.

In March, the state Department of Health and Senior Services held its annual inspection of the St. Louis clinic.

In the statement released Friday, the state said regulators identified “serious concerns” during that inspection regarding the handling of fetal tissue extracted from abortions.

The state called the federal Centers for Medicare & Medicaid Services, which opened an investigation into a laboratory contracted by Planned Parenthood to handle fetal tissue, the state said. Federal investigators were trying to determine why women remained pregnant post-abortion. That lab cooperated with the federal agency, confirming the concerns regarding the handling of the tissue provided by Planned Parenthood, the state said.

A failed surgical abortion is “very rare,” the state said in its statement, and can usually be detected by the physician who performed the abortion.

Failed or incomplete abortions occur in less than 1 percent of procedures, according to the American Pregnancy Association. Women at greater risk of incomplete abortion are those in early stages of pregnancy, those who have prior Cesarean sections or those with a misshapen uterus.

Incomplete abortion results in termination of pregnancy in most cases and can lead to prolonged bleeding, cramping and infection. An additional procedure called a dilation and curettage may be required to remove remaining tissue.

As a result of the federal investigation into the lab, Columbia, Mo.-based Boyce & Bynum Pathology Laboratories, lost its accreditation, the state said.

A representative from the lab could not be reached.

Further investigation has been limited, the state said on Friday, by the “refusal of Planned Parenthood” to make available to investigators the doctors who performed the abortions.

Lisa Cox, spokeswoman for the state department, said Planned Parenthood performed “multiple” failed abortions, but would not say how many.

The Centers for Medicare & Medicaid Services told Boyce & Bynum on Thursday that the laboratory’s accreditation was restored. It was not immediately clear why.

But the re-accreditation of Boyce & Bynum, the state said in its statement, allowed the state to publicly release details of its Planned Parenthood investigation for the first time.

The legal fight stems from the state’s request to interview in its investigation seven physicians, all who had worked at the Planned Parenthood clinic.

If the facility’s license is not renewed, Missouri would become the first U.S. state without an abortion clinic since the Supreme Court’s Roe v. Wade decision in 1973 that established a woman’s right to terminate her pregnancy.

Late last month, Gov. Mike Parson signed one of the nation’s strictest abortion laws, banning them after the eighth week of pregnancy.