List gynecological and obstertrical differential diagnosis of decreased fetal movement in 2nd trimester

1. Placental insufficiency

2. Umbilical cord abnormalities
3. Fetal growth restriction
4. Maternal conditions such as gestational diabetes
5. Fetal anomalies
6. Maternal obesity
7. Intrauterine infection
8. Maternal drug or alcohol use
9. Hypertensive disorders in pregnancy
10. Fetal sleep cycles
11. Fetal position

It is important for pregnant individuals to seek medical attention if they experience a decrease in fetal movement in the second trimester, as it could be a sign of a serious complication.