NEWARK -- Four women are challenging a New Jersey law that they say unfairly targets same-sex couples hoping to conceive a child through fertility treatments.

Erin and Marianne Krupa of Montclair, Sol Mejias of North Bergen, and Sarah Mills of Union City, filed suit on August 1 against Richard J. Badolato, the commissioner of the state Department of Banking and Insurance.

According to the suit, the women were denied insurance coverage for their fertility treatments because of the wording of an N.J. law that requires women to prove their infertility not only through medical diagnosis, but through unprotected heterosexual sex. The law, the four women argue in the suit, discriminates against infertile gay couples trying to conceive.

According to the civil suit, the Krupas have been trying to conceive a child since 2013. Fertility doctors found several benign cysts on Erin Krupas' uterus, and found that she suffered from endometriosis, making her infertile, the suit says.

State law requires large insurance providers to cover costly fertility treatments for patients medically unable to have children. The couples take issue with how the law defines infertility, which includes the inability to become pregnant after one or two years of unprotected sex, depending on a woman's age. Insurance companies have been able to deny coverage to gay patients who, although they have been medically diagnosed infertile, do not fit the definition, the suit says.

"Despite having a medical diagnosis of infertility, because, as a lesbian in a committed relationship, Erin could not show that she had unprotected sexual intercourse with a man for the requisite period, the Krupas were not protected by the mandate," the suit reads.

The Krupas, and Mejias and Mills -- who are attempting to start families with their respective partners -- are coincidentally all clients of Horizon Blue Cross Blue Shield. All of the women were initially denied coverage, and paid for the costly procedures out of pocket, the suit claims.

After the Krupas spent more than $25,000 on failed infertility treatments, the suit says, the insurance company did agree to pay for their continued treatments. It has denied to pay for Meijas' and Mills' treatments, under the definition in the state statute, the suit said.

"Horizon covers infertility services equally regardless of sexual orientation. We interpret the 2001 New Jersey law defining infertility in a gender and orientation neutral manner and our coverage standard complies with federal non-discrimination requirements," a Horizon Blue Cross Blue Shield spokesman said in a statement to NJ Advance Media Monday morning.

"Members unable to conceive due to medical or biological reasons are covered for the specific infertility benefits included in their policy. Horizon is committed to equality, values our LGBTQ members, and is sensitive to their unique healthcare challenges and needs. We regularly review our standards and procedures to ensure parity and fairness for all of our members."

The suit does not take issue with Horizon's denials, but rather the state law that inspired them, it says. The state Department of Banking and Insurance acknowledged, but did not respond, to a request for comment on the suit Monday.

Grace Cretcher, an attorney representing the women, said the suit is both personal for the plaintiffs attempting to have children, and political, working against a mandate that she called "so narrowly and specifically worded."

Given the passage of marriage equality laws and advocacy on behalf of LGBTQ rights in recent years, Cretcher said she finds that many New Jersey residents are surprised that the wording in the mandate has not been changed.

"The status quo is very powerful," she said. "Things have been this way for so long, they feel normal to us...(but if something) feels unfair, I always encourage people to question it."

As originally reported in the New York Times, New Jersey is one of 15 states that requires insurance companies to cover fertility treatments. Of those, California and Maryland have updated the definitions of infertility in those laws to be inclusive of same sex couples, the article says.

Though none of the women who filed the suit have been able to conceive yet, and all are continuing to try via various fertility methods, they say in the suit that they are hoping not only to recoup money they have spent on treatments, but change the law for future lesbian couples trying to have children.

"Every day that New Jersey law continues to exclude women in same-sex relationships from the protections of the infertility mandate, these women must either wait for the law to change as their childbearing years continue to slip away or, if they have any available resources, bankrupting themselves and their families in order to pay for fertility care that is automatically covered for straight women," it says.

Jessica Mazzola may be reached at jmazzola@njadvancemedia.com. Follow her on Twitter @JessMazzola. Find NJ.com on Facebook.