A 1999 research study on baby powder and ovarian cancer made an interesting observation.

Since the 1970s, it has been suspected that talc-based baby powder on a woman’s genitals could increase the risk of certain types of cancer, including ovarian cancer. But most baby powder ovarian cancer studies were case-cohort studies, a type of observational study where women with an outcome, ovarian cancer, are identified and compared with a very similar group of women.

Results from these studies have been inconsistent, and they are subject to several types of biases. For example, these studies asked women who developed ovarian cancer if they used baby powder on their genitals after they developed ovarian cancer. Women in this situation might be more likely to remember using baby powder since they had a more negative outcome. Researchers call this “recall bias,” a possible disruptive factor in this type of study.

But in this particular baby powder ovarian cancerstudy, researchers performed a prospective cohort study. In this type of study, a group of similar patients are followed and questioned over time, making it less subject to recall bias.

Researchers here used data from a research project called the Nurse’s Health Study, which followed 121,700 female nurses for decades, including questionnaires on baby powder usage and cancer. Both the size and study design involved in this project lend credence to researchers’ observations.

In this case, researchers observed that under most conditions, using baby powder on the genitals was not linked with an increased risk of ovarian cancer — with one serious exception. Women who used talc-based baby powder on their genitals were more likely to develop aggressive, invasive ovarian cancer compared to women who did not.

Researchers also looked into several other factors, to see if tubal litigation could decrease this risk, as this procedure could hypothetically make it harder for talc particles to move up into the ovaries, but researchers were unable to prove this.

Researchers also looked at the risk of ovarian cancer in older women who used talc-based baby powder separately and compared them. This was because the main ingredient in many types of baby powder is a mineral called talc.

Talc tends to occur alongside asbestos deposits and prior to the development of stricter regulations in the 1970s, baby powder sometimes contained trace amounts of asbestos — a known cancer-causing agent.

Curiously, women in this older age group had no special risk seen outside the general study population, though the same trend was seen that women who used baby powder on their genitals had a higher risk of aggressive ovarian cancer compared to their peers.

Baby powder cancer lawsuits have been filed by women who developed ovarian cancer after using baby powder on their genitals. These baby powder lawsuits allege that companies did not adequately warn the public that using their products could cause ovarian cancer, despite research dating back to the 1970s suggesting that baby powder could cause ovarian cancer.

Additionally, ovarian cancer lawsuits allege that some companies, like Johnson & Johnson, specifically marketed talc-based products for genital use, like Johnson & Johnson’s “Shower to Shower.” These ovarian cancer lawsuits typically seek to recoup the costs of medical care, legal fees, and other costs allegedly linked to baby powder ovarian cancer.