Introduction Maternal gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy. GDM can adversely affect the short- and long-term health of mothers and their newborns. Aim This study aims to determine the association between maternal glycemic parameters with adverse maternal outcomes and baseline characteristics among women with GDM. Settings and Design Observational, prospective study. Materials and Methods Sixty-six pregnant women visiting outpatient department of a parent hospital who were diagnosed with GDM by an obstetrician were included in the study. Glycemic parameters were documented at the time of diagnosis (at 24 weeks of pregnancy). The maternal outcomes were studied after 24 hours of delivery. Results The mean age of the women was 29.05 ± 3.98 years and 36.4% of the women were primipara. Among 66 women, 47% had a family history of diabetes mellitus, and that 48.28% of them belonged to first-degree relatives. Body mass index indicated in prepregnancy status 39.4% of them were overweight. In glycemic parameters, 63.6 and 93.9% of the women had increased fasting blood sugar and postprandial blood sugar values, respectively. Hemoglobin A1c (HbA1c) was elevated in 45.5% of the women. The maternal outcome showed that 30.30% of the women underwent cesarean section, 18.18% had preeclampsia, and 15.16% of them had increased weight gain (>11kg). There was a significant association between HbA1c and preeclampsia, p = 0.044. Conclusions The study reiterates that GDM has a poor maternal outcome, the mother is at risk to develop preeclampsia, increased maternal weight gain, and interference of cesarean section is more. Clinical Significance During the antenatal period among GDM mothers' glycemic control is very essential. Any variation in the glycemic parameters of the mother will lead to poor maternal outcomes.