Health Risks for Nulliparous Women

Nulliparous is the medical term for a woman who has never given birth either by choice or for any other reason. This term also applies to women who have given birth to a stillborn baby, or a baby who was otherwise not able to survive outside the womb.

The word has Latin roots, from "null" meaning "not" and the verb "parere," meaning "to bring forth."

Nulliparous women are at greater risk for some health conditions than their childbearing counterparts, including breast and reproductive cancers.

For decades, the scientific community has known nulliparous women have an increased risk for cancers of the reproductive system, including ovarian and uterine cancers. The increased risk was thought to be due to the fact that women with biological children have fewer ovulatory cycles.

But research on breast cancer incidence in nulliparous nuns found increased rates to occur into menopause and was therefore unassociated with ovulatory cycles.

Women who have children before the age of 20 have a lower lifetime risk of breast cancer compared to their nulliparous counterparts, but the young mothers have a higher risk for the first 15 years after their pregnancy. Mothers with five full-term pregnancies are about 50 percent less likely than nulliparous women to develop breast cancer.

Breastfeeding, which nulliparous women don't experience, also has been found to reduce the risk of breast cancer.

And among nulliparous women age 35 and older, there’s a greater risk of having a stillborn baby, according to a study of 1.8 million pregnancies reported in the journal Obstetrics & Gynecology.

Early research on IUD use among nulliparous women suggested that it was more difficult for them to become pregnant for the first time following the long-term use of an IUD (intrauterine device). This was compared to the use of a barrier method, such as a diaphragm or condom. 

But more current researchhas found no increased risk of infertility among IUD users who are in stable, monogamous sexual relationships.

More often nulliparous women were likely to have had exposure to more sexual partners, and therefore more likely to have been exposed to a sexually transmitted disease (STD). Infertility is a side effect of many STDs.

The stages of labor during birth have different norms for mothers and nulliparous women. For first-time moms, the latent stage (when there are mild and infrequent contractions) is about 1.5 hours longer, the active labor stage is almost 2 hours longer and the second stage (the time between when the cervix dilates completely and the baby comes out) is about 50 minutes longer.