Objective To analyze the levels of C1q tumor necrosis factor-related protein 9 (CTRP9), ghrelin, thyroid stimulating hormone (TSH), and thyroid peroxidase antibody (TPO-Ab) in patients with subclinical hypothyroidism (SCH) during pregnancy and their relationship with pregnancy outcomes. Methods 528 pregnant women with SCH were included in the study as a case group. The time of inclusion was from January 2023 to August 2024. The hospital was Nanyang Central Hospital, and another 528 pregnant women with normal prenatal examination were selected as a control group. Results After 2 weeks in the group and after delivery, the serum Ghrelin, TSH and TPO-Ab levels in the treatment group were lower than those in the untreated group, while the serum CTRP9 level was higher than that in the untreated group (P<0.05). Compared with untreated group, the total incidence of adverse pregnancy outcome in treatment group was lower (P<0.05). Compared with the control group, the total incidence of adverse pregnancy outcome, serum Ghrelin, TSH levels, TPO-Ab positive ratio were higher and serum CTRP9 level was lower in the case group (P<0.05). Compared with the group with good pregnancy outcome, the level of serum CTRP9 in the group with bad pregnancy outcome was lower, while the levels of serum Ghrelin, TSH and the positive proportion of TPO-Ab were higher(P<0.05). Draw ROC curves to analyze the predictive value of CTRP9, Ghrelin, TSH, and TPO Ab detection alone and in combination for pregnancy outcomes in SCH patients during pregnancy. The area under the curve (AUC) is 0.732, 0.738, 0.735, 0.709, and 0.857, with the highest AUC for combined detection (P<0.05). Conclusion After treatment, it can stabilize the level of serum indicators related to SCH during pregnancy and improve the pregnancy outcome. In addition, SCH during pregnancy can increase the probability of adverse pregnancy outcome, and the serum levels of CTRP9, Ghrelin, TSH and TPO-Ab are all abnormally expressed in patients with SCH during pregnancy, and the combined determination is helpful to improve the pregnancy outcome of patients with SCH during pregnancy.