Delivery of a very low birth weight infant and increased maternal risk of cancer and death: a population study with 16 years of follow-up

Background: Pregnancy complications represent sentinel events for women’s future health. We investigated whether delivery of a very low birth weight (VLBW) infant is associated with increased maternal risk for future incidence of maternal cancer and death. Methods: This is a population-based cohort study of linked Israeli Ministry of Health datasets between 1995 and 2011. Women delivering a live singleton <1,500 g infant (VLBW group) were compared with women delivering a live singleton, 3,000–3,500 g (control). The first pregnancy eligible for entry into the study, the “index pregnancy,” reflected exposure status for each participant. Primary outcomes were maternal cancer and death. Cancer diagnoses were further classified by primary site. Cox regression models adjusted for follow-up period and maternal characteristics at index pregnancy: Age at delivery, ethnicity, years of education, marital status, and previous cancer afforded calculation of hazard ratios (HR) and 95 % confidence intervals (CI). Findings: During the study period, 982,091 mothers with 2,243,736 live births were identified; of these, 13,773 births were VLBW eligible for inclusion in the study and 448,743 births were controls. Groups differed significantly by average follow-up and all maternal characteristics evaluated. Overall rate of cancers and death was significantly increased for VLBW women compared to controls: 18.4 versus 15.7 % and 7.3 versus 3.2 %, both p < 0.0001. The Cox model adjusted for maternal characteristics showed significantly increased risk of cancer (all sites) in the VLBW women: HR 1.18 (95 % CI 1.02–1.37) and for death: HR 2.13 (95 % CI 1.68–2.71), and an increased combined risk of both outcomes: HR 1.4 (95 % CI 1.23–1.59). Interpretation: The delivery of a VLBW newborn is an independent lifetime risk factor for subsequent maternal cancers and death. These women may benefit from targeted cancer screening and counseling.