hi, 876 gms at 26 weeks of geatation is an appropriate weight for the fetus. when your wife completes 28 weeks the weight should be somewhere nearing 1 kg. GESTIN is a progesterone agent. its given prophylactically in her so as to prevent preterm labour. it may cause side effects like edema of the feet or bloating sensation. so in case if she develops then consult your doctor back regarding discontinuing it. L- arginine and aminofit are aminoacid preparations. few reports available saying its role in growth of fetus and secretion of liquor, but few reports deny that. but in my view your wife can continue taking it, because there is no harm done .