Objective: The aim of this study was to evaluate interleukin (IL)-1 β and IL-1 receptor antagonist (IL-1ra) levels in gingival crevicular fluid (GCF) and serum (S) in nonsmoking women with normal birth (NB), preterm low birth weight (PLBW), and intra-uterine growth retardation (IUGR). Materials and Methods: In this unmatched case-control study design, 64 women with NB, 45 women with PLBW, and 47 women with IUGR were recruited within 24 h delivery. Clinical periodontal parameters were recorded. IL-1 β and IL-1ra levels in GCF (pg/30 s) and serum (pg/ml) of were evaluated using commercial enzyme immunoassay and ELISA kits. Results: Greater pocket depth and clinical attachment loss were observed in PLBW and IUGR women than in NB women (P < 0.05). The total amounts of IL-1ra and IL-β of GCF were higher levels in NB women than PLBW and IUGR women (P < 0.05). The lowest total amount of IL-1ra of GCF was found in IUGR women (P < 0.05). The concentrations of IL-1ra in serum samples were not statistically significant for any of the study groups (P > 0.05). Conclusion: It can be suggested that worse periodontal conditions and the low levels of IL-1ra in GCF may be an important factor in adverse pregnancy outcomes.