Cancer survivors more likely to have preterm birth, cesarean delivery
Adult survivors of adolescent and young adult cancers were more likely to experience preterm birth, low birth weight and cesarean delivery compared with births by women never diagnosed with cancer, according to study results.
“Our research suggests that women treated with chemotherapy may continue to have an increased risk for preterm birth in the future,” Hazel B. Nichols, PhD, assistant professor in the department of epidemiology at UNC Gillings School of Global Public Health, told HemOnc Today.
Women diagnosed with cancer during their reproductive ages may want to and eventually go on to have children after treatment, Nichols said. However, there are few studies that focus on the effect of cancer therapies on children born from mothers diagnosed with and treated for cancer during childbearing years.
Therefore, Nichols and colleagues linked 2000 to 2013 cancer diagnosis data from The North Carolina Central Cancer Registry with statewide 2000 to 2014 birth certificate data to identify live births to 2,598 adult cancer survivors (mean maternal age, 31 years; standard deviation, 5). Researchers randomly selected a comparison cohort of births of 12,990 women without cancer diagnosis from birth certificate files who were frequency matched with year of delivery and maternal age of women in the cancer survivor cohort.
The goal was to study health outcomes of the first child born from women after cancer diagnosis, and whether there are potential risks for children born from mothers who are cancer survivors.
A greater proportion of women cancer survivors than controls were non-Hispanic white (78% vs. 59%).
Births to cancer survivors had increased prevalence of preterm birth (prevalence ratio [PR] = 1.52; 95% CI, 1.34-1.71), low birth weight (PR = 1.59; 95% CI, 1.38-1.83) and cesarean delivery (PR = 1.08; 95% CI, 1.01-1.14) compared with the comparison cohort.
“The increased risk for preterm birth in our study was remarkably similar across different categories of ages at diagnosis, from an overall 65% increase among women aged 15 to 19 years at cancer diagnosis to 64% increase among women aged 35 to 39 years at cancer diagnosis,” Nichols said.
The highest prevalence of these outcomes was found among women diagnosed during pregnancy.
Women diagnosed with cancer during pregnancy had an almost threefold increase for preterm birth (PR = 2.97; 95% CI, 2.47-3.58) and low birth weight (PR = 2.82; 95% CI, 2.25-3.53). These women had a 20% increase in cesarean delivery (PR = 1.21; 95% CI, 1.06-1.38) relative to the comparison cohort.
Further analyses stratified by cancer group showed that preterm birth was most prevalent among births to women diagnosed with breast cancer (PR = 1.98; 95% CI, 1.56-2.51), Hodgkin lymphoma (PR = 1.59; 95% CI, 1.06-2.37), non-Hodgkin lymphoma (PR = 2.11; 95% CI, 1.42-3.13) and gynecologic cancer (PR = 2.58; 95% CI, 1.83-3.63). In addition, the prevalence of low birth weight was greater among births to survivors of breast cancer (PR = 1.59; 95% CI, 1.18-2.15), non-Hodgkin lymphoma (PR = 2.41; 95% CI, 1.58-3.67) and gynecologic cancer (PR = 2.74; 95% CI, 1.86-4.05).
“Our findings regarding preterm birth and [low birth weight] are in line with those of recent studies based outside the United States,” the researchers wrote.
The researchers also observed no difference in small-for-gestational-age between the two cohorts.
“We believe that increases in low birth weight are largely driven by associations with preterm birth, because babies that are born early are more likely to also be born small,” Nichols said. “Our study does not have information on the cause of labor, but it is possible that the increase in cesarean section and preterm birth are due, in part, to planned early deliveries to begin cancer treatment.”
The findings suggest the need for additional surveillance of pregnancies in this population.
“A woman’s medical history, including conditions such as diabetes, high blood pressure, epilepsy or cancer, can be used to identify high-risk pregnancies,” Nichols said. “Women with a previous cancer history may warrant more frequent prenatal visits towards the end of pregnancy, similar to women with advanced maternal age.” – by Melinda Stevens
For more information:
Hazel B. Nichols, PhD, can be reached at 2102A McGavran-Greenberg Hall, CB #7435, Chapel Hill, NC 27599-7435; email: firstname.lastname@example.org.
Disclosures: Nichols reports no relevant financial disclosures. One researcher reports research funding from Angiochem, Merck, Merrimack, Lily, Oncothyreon and PUMA; uncompensated advisory roles with Angiochem, Genentech, GERON, Kadmon, Lily, Merrimack, Nektar, Novartis, Sanofi and to-BBB; and royalties from Jones & Bartlett Learning and UpToDate.