In a non-diabetic high risk pregnancy the ideal time for non stress test monitoring is:

Explanation

Intervals between NST testing “The interval between tests is arbitrarily set at 7 days. According to ACOG, more frequent testing is advocated for women with posterm pregnancy, type I diabetes mellitus, IUGR or gestational hypertension. In these circumstances some investigators recommend twice weekly (i.e. after 72 hours) with additional testing performed for maternal or fetal deterioration regardless of the time elapsed since the last test. Others recommend NST daily. Generally daily NST is recommended with severe preeclampsia remote from term.”