I presume that current conception leading to pregnancy is normal in nature and not as a result of assisted reproductive technique such as IVF etc. If so, then HCG injections are not indicated. HCG injections are meant for female infertility when ovulation does not take place (this is not the case with your wife), habitual abortion, proven corpus luteum deficiency and in cases where IVF is used.
Susten contains a hormone called progesterone. It is to be given ONLY, if there is proven, documented deficiency of this hormone before conception to facilitate pregnancy. It is used in assisted reproductive techniques such as IVF, but never in normal conception. Its side effects include cramps, headache, nausea, depression, nervousness, somnolence, breast changes, weight increase, fluid retention and rarely death of the fetus in uterus. it is prohibited for use during pregnancy. Its use during early pregnancy can lead to birth defects in the baby such as cleft palate, cleft (hare) lip, heart defects. Rare cases of fetal death and spontaneous abortion have been reported in women given progesterone. Therefore Susten is not indicated in your wife’s case. Since now Alkaline phosphatase is normal, there is no cause for concern. The only medicine required in your wife's case is folic acid with iron (such as Fecontin-Z Continus one a day) till delivery.