<s>[INST] context: To get started, sit with your feet up or lie on your side. Count each of your baby'smovements as one kick, and count until you reach 10 kicks or movements. Most of the time it will take less than a half-hour, but it could take as long as two hours. Log your recorded times into a Count the Kicks chart. The lecithin-sphingomyelin ratio (aka L-S or L/S ratio) is a test of fetal amniotic fluid to assess for fetal lung immaturity. Lungs require surfactant, a soap-like substance, to lower the surface pressure of the alveoli in the lungs. Human placental lactogen (hPL), also called human chorionic somatomammotropin (HCS), is a polypeptide placentalhormone, the human form of placental lactogen (chorionic somatomammotropin). Its structure and function are similar to those of human growth hormone. It modifies the metabolic state of the mother during pregnancy to facilitate the energy supply of the fetus. hPL has anti-insulin properties. hPL is a hormone secreted by the syncytiotrophoblast during pregnancy. Like human growth hormone, hPL is encoded by genes on chromosome 17q22-24. HPL is present only during pregnancy, with maternal serum levels rising in relation to the growth of the fetus and placenta. Maximum levels are reached near term, typically to 5-7 mg/L. Higher levels are noted in patients with multiple gestation. Little hPL enters the fetal circulation. Its biological half-life is 15 minutes. [/INST] question: To diagnosis foetal wellbeing of foetus, most reliable method -(UPSC 97) | options: A: L:S ratio B: HPL levels C: Kick test D: Ultrasound | answer: D </s>