A 33-year-old woman with bipolar I disorder presents to the PMHNP at 10 weeks gestation. She has a severe illness course with five prior manic episodes, three of which involved psychotic features and required psychiatric hospitalization. Her most recent episode, occurring 14 months ago, involved grandiose delusions, dangerous spending, and a suicide attempt during a mixed state. She has been stable on lithium 1200 mg daily (level 0.8 mEq/L) and quetiapine 400 mg at bedtime for the past year. She discovered she was pregnant unexpectedly and discontinued both medications abruptly five days ago upon receiving a positive home pregnancy test. She currently denies manic or depressive symptoms but appears mildly anxious. The PMHNP evaluates the risk-benefit considerations for this clinical scenario. Which of the following best reflects evidence-based assessment of this situation?