Adolescent and young adult (AYA) patients diagnosed with cancer during pregnancy have a higher risk of adverse birth outcomes, according to research published in the Journal of the National Cancer Institute.

The study showed that AYA cancer patients have higher rates of preterm birth and children with lower birth weights when compared with AYAs who do not have cancer. Type of cancer and receipt of chemotherapy were associated with both outcomes.

The study included data from 1291 AYA patients (aged 15-39 years) who were diagnosed with cancer during pregnancy from 1999 to 2015. The most common cancer types were breast (22.5%), thyroid (19.8%), and gynecologic (13.3%) cancers. 

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Most patients were diagnosed with local (50.9%) or regional (31.3%) cancer. Cancer diagnoses were made during the first trimester in 23.8% of patients, in the second trimester in 40.3%, and in the third trimester in 35.9%. A majority of patients (63.4%) underwent surgery, and 33.3% received chemotherapy.

The researchers compared adverse birth outcomes between the AYA cancer patients and 5084 AYA patients without cancer. The patients were matched based on age, race/ethnicity, and delivery year.

Adverse outcomes of live births were generally higher among the cancer patients. Low birth weight occurred in 30.1% of cancer patients and 9.0% of non-cancer patients (prevalence ratio [PR], 3.36; 95% CI, 2.97-3.79; P <.01). 

Preterm birth occurred in 25.1% of cancer patients and 7.2% of non-cancer patients (PR, 3.51; 95% CI, 3.06-4.02; P <.01). Very preterm birth occurred in 5.7% and 1.2%, respectively (PR, 4.95; 95% CI, 3.53-6.94; P <.01). 

The proportion of infants assigned an Apgar score lower than 7 was 2.7% among cancer patients and 1.5% among non-cancer patients (PR, 1.76; 95% CI, 1.12-2.78; P =.02).

The rates of any birth defect were similar between the groups, at 5.2% in the cancer patients and 4.7% in the non-cancer patients (P =.48). 

However, live births with heart or circulatory system defects were more common among the cancer patients than among the non-cancer patients — 2.2% and 1.3%, respectively (P =.01). 

Cancer surgery was not associated with outcomes, but receipt of chemotherapy was significantly associated with a higher prevalence of preterm birth (adjusted PR [aPR], 1.82; 95% CI, 1.53-2.17) and low birth weight (aPR, 1.36; 95% CI, 1.17-1.58). 

Cancer type was associated with the prevalence of preterm birth, low birth weight, and cesarean section. Outcomes were similar between patients with skin cancer and those with thyroid cancer (reference). However, patients with genitourinary cancers had a higher prevalence of preterm birth.

Patients with breast cancer, lymphoma, or head and neck cancer had a higher prevalence of preterm birth and low birth weight. Patients with gynecologic cancers, gastrointestinal cancers, leukemias, sarcomas, or central nervous system cancers had a higher prevalence of preterm birth, low birth weight, and cesarean section. 

“AYA women diagnosed with cancer during pregnancy experience a disproportional burden of adverse birth outcomes, illustrating the dilemmas they and their providers face in balancing care for cancer and pregnancy,” the researchers concluded.

“Optimizing outcomes for these women and their families requires shared decision-making, sensitive communication, access to legal and safe abortion, multidisciplinary care, and supporting a woman’s autonomy to make informed and value-concordant decisions about her body when faced with both pregnancy and cancer.”

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Betts AC, Shay LA, Lupo PJ, et al. Adverse birth outcomes of adolescent and young adult women diagnosed with cancer during pregnancy. J Natl Cancer Inst. Published online March 13, 2023. doi:10.1093/jnci/djad044