The proportion of women who received cancer treatment during pregnancy has increased significantly in recent decades, according to researchers in Europe.
Researchers reported that newborns exposed to antenatal chemotherapy may be at increased risk for being small for gestational age and for admittance to the NICU compared with other newborns.
“The incidence of cancer during pregnancy is estimated to be one in 1,000 pregnancies,” Frederic Amant, MD, PhD, professor of gynecologic oncology at Netherlands Cancer Institute in Amsterdam, and colleagues wrote. “Breast cancer, hematological cancer, cervical cancer and melanoma are the most commonly diagnosed malignant diseases during pregnancy. Although cohort studies of maternal and fetal outcomes [among] these women have included overall maternal and obstetric outcomes, most of these studies have small sample sizes and short follow-ups.”
Amant and colleagues performed a descriptive cohort study of 1,170 women diagnosed with cancer during pregnancy at 37 centers participating in the International Network on Cancer, Infertility and Pregnancy (INCIP) registry from Jan. 1, 1996, to Nov. 1, 2016. The researchers used log-binomial regression to evaluate temporal changes in patient characteristics, outcomes and treatment methods. Complications analyzed included preterm, prelabor rupture of membranes or preterm contractions, small for gestational age and NICU admission.
Approximately two-thirds (n = 779; 67%) of patients received treatment for their cancers during pregnancy. The likelihood of being treated while pregnant increased every 5 years (RR = 1.1; 95% CI, 1.05-1.15), due mainly to an increase in use of chemotherapy (RR = 1.31; 95% CI, 1.2-1.43).
Most singleton pregnancies (n = 955 of 1,089; 88%) ended in a live birth. Of these, nearly half (n = 430 of 887; 48%) ended preterm.
Every 5 years, rates of live births increased (RR = 1.04; 95% CI, 1.01-1.06) and iatrogenic preterm deliveries decreased (RR = 0.91; 95% CI, 0.84-0.98).
The researchers identified a relationship between platinum-based chemotherapy and infants being born small for gestational age (OR = 3.12; 95% CI, 1.45-6.7), as well as a relationship between taxane chemotherapy and admission to a NICU (OR = 2.37; 95% CI, 1.31-4.28).
NICU admission appeared dependent on cancer type. Gastrointestinal cancers had the highest risk (OR = 7.13; 95% CI, 2.86-17.7), whereas thyroid cancers had the lowest risk (OR = 0.14; 95% CI, 0.02-0.9) compared with breast cancer.
Abdominal or cervical surgery appeared associated with a lower likelihood of admission to a NICU (OR = 0.3; 95% CI, 0.17-0.55), which researchers noted was unexpected.
“These findings strengthen the need for pregnant women who are treated for cancer to be extensively counseled about peripartal fetal and maternal risk,” Christhardt Köhler, MD, professor of gynecologic oncology at University of Cologne in Germany, and Simone Marnitz, MD, professor at CyberKnife Center in Cologne, wrote in an accompanying editorial. “However, due to its heterogeneity, the INCIP database analysis reported by de Haan and colleagues has minor value for women’s oncological management. Carefully planned studies combining women’s cancer-specific management in pregnancy, oncological outcomes and long-term effects on children’s development are urgently needed to improve our limited knowledge.” – by Andy Polhamus
Disclosures: One researcher reports grants from University Hospitals Leuven during the study. Köhler and Marnitz report no relevant financial disclosures.