Background Telomere length is a marker of cumulative damage to the cell, and has been associated with cardiovascular disease, hypertension, and diabetes. Findings The association of telomere length with pre-eclampsia and gestational diabetes mellitus (GDM) was examined in a nested case-control study. Circulating leukocyte telomere length was measured by Quantitative-PCR. Mean and median telomere length among cases and controls was compared, and logistic regression was used to model the outcomes as a function of tertile telomere length, with control for effects of potential confounders. Mean telomere length in pre-eclampsia cases was 0.77 (SD 0.14), in GDM cases was 0.73 (SD 0.10), and in controls was 0.74 (SD 0.14). The adjusted odds ratio comparing the highest tertile to the lowest for pre-eclampsia was 0.92 (0.15-5.46), and for gestational diabetes was 0.65 (0.13-3.34). Conclusions Further study is necessary to determine if telomere length is associated with these pregnancy complications.