Nulliparous is a medical term that describes a female who has never given birth to a live baby. This may be because they choose not to become pregnant, or they experience pregnancy complications.
According to the National Institutes of Health (NIH), the nulliparous population represents 40% of annual births in the United States.
In this article, we define nulliparous and its related terms. We also cover the potential health impacts doctors may associate with being nulliparous. Lastly, we discuss safe contraception options for nulliparous individuals.
Nulliparous refers to a female of reproductive age who has never had a live delivery.
Primiparous describes women who have given birth to one live baby or who are experiencing their first pregnancy.
The term multiparous refers to women who have given birth to more than one baby.
Multiparous includes women who have had two or more live birth. It also covers women who have given birth to more than one baby at a time, for example, twins, triplets, etc.
Although nulliparity alone does not determine a person’s health status, nulliparous women may have a higher risk for certain medical conditions.
Risk of ovarian and uterine cancers
According to the American Cancer Society (ACS), women who give birth for the first time after 35 years of age, and those who are nulliparous, have a higher risk of ovarian cancer and endometrial cancer.
The authors of the study linked the increased reproductive cancer risk with Catholic nuns abstaining from sex and not using contraception.
However, a 2013 study claimed that the nun study did not account for the age-related differences in cancer death risk.
When the authors compared the nuns to the control population, those nuns aged over 80 years showed the highest death rates from breast, uterine, and ovarian cancers. Ovarian and uterine cancer death rates declined after age 80 in the control population.
The authors of the 2013 study concluded that nulliparity may instead have some protective effects against ovarian and uterine cancer for women younger than 60.
According to the Centers for Disease Control and Prevention (CDC), about 12% of women between 15–44 years of age in the U.S. have difficulty getting pregnant.
It is unclear whether nulliparity raises the risk of infertility. However, nulliparity may indicate underlying fertility issues.
The fact that a woman has never given birth before does not necessarily mean they are infertile. A nulliparous woman may have no problems getting pregnant or giving birth in the future.
Infertility can take many forms. For some, infertility means the individual cannot conceive. Other women who experience infertility may become pregnant but are unable to maintain a pregnancy to full term.
A nulliparous person with one or more risk factors for infertility may have difficulty getting pregnant or sustaining a full-term pregnancy. The risk factors for infertility include:
- history of smoking
- excessive alcohol use
- having overweight or underweight
- history of sexually transmitted infections (STIs)
- polycystic ovarian syndrome (PCOS)
- primary ovarian insufficiency
Infertility rates are higher among women with a history of two or more pregnancy losses, according to one 2017 study.
Pregnancy and labor risks
In a 2019 study of 137,791 women, researchers found that the risk for preterm delivery and pregnancy-related high blood pressure began increasing at ages 20–24 in nulliparous women. However, the risk for the same complications does increase until ages 40–49 years for women who have had one or more deliveries.
Labor may take longer for nulliparous women.
In a 2020 study of 35,146 deliveries, researchers observed that the first stage of labor lasted 141 minutes longer for nulliparous women than multiparous women.
The latent phase of labor, which refers to the time it takes the cervix to reach 10 centimeters in diameter, took 120–140 minutes longer for nulliparous women.
Nulliparity describes a person’s birthing history. It is not a medical condition or a diagnosis. There are several possible reasons for nulliparity.
An individual might be nulliparous by choice, as a result of using contraception or abstaining for sex.
Other women may have a history of pregnancy but did not have a live delivery due to pregnancy loss, stillbirths, or elective abortions.
Nulliparous females can safely use most forms of contraception.
In a 2017 committee statement, the American College of Obstetrician and Gynecologists state that intrauterine devices (IUDs) and contraceptive implants are the safest and most effective contraceptive options for nulliparous females and adolescents.
Despite their effectiveness, IUD use remains low among nulliparous females. According to a 2015 study, rates of long-acting reversible contraception use among nulliparous females in the U.S. increased from 2.1% to 5.9% between 2009 and 2012.
The authors of another 2015 study suggest that nulliparous and young females are unaware that IUDs are available. The authors also conclude that the low adoption rates of IUDs result from provider misconceptions.
According to the study, only about 43% of providers considered IUDs as first-line birth control options for adolescents.
Females are nulliparous if they have not had a live delivery. This may be due to pregnancy complications or because they choose to use contraception or abstain from sex.
Some research has associated nulliparity with certain health risks, such as higher rates of cervical, uterine, and breast cancer. However, being nulliparous does not mean a person is less healthy or has fertility problems.
Numerous factors influence a person’s risk for any medical condition. Factors such as age, family history, and lifestyle choices likely have more significant impacts on a person’s health status than their delivery history.
People can lower their risk for reproductive cancers by attending regular screenings and addressing personal risk factors with their doctor.