Although rare, maternal cancer during pregnancy is associated with elevated risks of stillbirth and neonatal death, according to a study published in the Journal of Clinical Oncology.1

Limited data are available on the risks of fatal outcomes like stillbirth and infant mortality in pregnancies complicated with cancer. For this study, investigators evaluated whether maternal cancer is associated with increased risks of these outcomes.

The researchers analyzed data from 3,947,215 singleton births in Sweden that occurred between 1973 and 2012. The investigators identified 984 births by women diagnosed with maternal cancer during pregnancy and 2723 births by women diagnosed with maternal cancer during the year after pregnancy.

Maternal cancer diagnosed during pregnancy was associated with an increased risk of stillbirth (incidence rate ratio [IRR], 2.5; 95% CI, 1.2-5.0). This association was confined to stillbirths where the fetus was assessed as small-for-gestational-age (SGA) at birth (IRR, 4.9; 95% CI, 2.2-11.0). Maternal cancer diagnosed during pregnancy was associated with 3-fold higher risk of preterm SGA births (relative risk, 3.0; 95% CI, 2.1-4.4).

Maternal cancer diagnosed during pregnancy or the year after pregnancy were associated with elevated risks for neonatal mortality (deaths within 0 to 27 days; IRR, 2.7; 95% CI, 1.3-5.6 and IRR, 2.0; 95% CI, 1.2-3.2, respectively) and preterm birth (IRR, 5.8; 95% CI, 5.3-6.5 and IRR, 1.6; 95% CI, 1.4-1.8, respectively).

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Preterm birth was responsible for 89% of the association between maternal cancer during pregnancy and neonatal mortality.

The findings reinforce the need for careful monitoring of fetal growth and cautious decision-making regarding preterm delivery in this population.

Reference

  1. Lu D, Ludvigsson JF, Smedby KE, et al. Maternal cancer during pregnancy and risks of stillbirth and infant mortality. J Clin Oncol. 2017 March 6. doi: 10.1200/JCO.2016.69.9439 [Epub ahead of print]