Hi heavenbuyer,hi fsfs,
We (ADMINS) intended to wait for longer time before we answer fsfs's question....just to activate other members to share their thoughts,feelings and experiences so we are happy of that....
but at the end of course we'll put the answer and here it is:

Stillbirth refers to the death of a baby after 20-24 weeks of pregnancy but before birth. To be termed stillbirth the baby will either have died in the womb, which is termed intra-uterine death, or during labour, which is termed intra-partum death; but in either case the baby will not have breathed or shown any actual signs of life after delivery.

The exact cause of about 70% of all stillbirths remains uncertain. These unexplained stillbirths might be due to one single factor, or to a combination of many. Even a post-mortem may not be able to find the exact cause of death. However, there are some known causes of stillbirth:

Congenital malformations

Congenital malformation refers to a genetic or physical defect in the baby. These defects can sometimes be so severe that further development is not possible in the womb and the baby dies. This is thought to be the cause of death for over 12% of stillbirths.

Ante-partum hemorrhage

In a healthy pregnancy, the placenta will naturally begin to separate from the lining of the womb as, or shortly after the baby is born. Ante-partum hemorrhaging happens when the placenta begins to separate prematurely. It may also occur in the case of placenta previa, when the placenta either lies over the opening of the womb, or is low in the womb, and the cervix dilates forcing the placenta away from the wall of the womb and the blood supply to the baby to be cut off. Bleeding during pregnancy can be a sign of these problems with the placenta. Over 16% of all stillbirths are caused by ante-partum hemorrhages.

Prematurity

Babies born early, particularly very premature babies, may not survive the trauma of labor. Premature labor may start spontaneously or it may have to be medically induced for the safety of the mother or baby or both.

Pre-eclampsia

This disorder of pregnancy has many potentially dangerous effects on the mother. If left untreated, or if the condition is severe, it can pose a serious threat to both the mother and baby.

Rhesus incompatibility

If a mother's blood group is Rhesus (Rh) negative and the baby's blood group is Rh positive then the mother may develop antibodies to the Rh positive baby. While a woman's first Rh positive baby will usually be born without complication, any antibodies she may have developed could remain in her blood, so appropriate treatment is given after the birth to help prevent subsequent babies with Rh positive blood to be stillborn.

Obstetric cholestasis

This is a liver disease of pregnancy, characterized by itching all over the body. Normal functioning of the liver is affected, meaning the blood is not effectively cleansed of potentially dangerous toxins. If it is not diagnosed and is left untreated it can lead to stillbirth.

Pre-existing maternal medical conditions

Some pre-existing maternal medical conditions such as diabetes, can be linked with an increased risk of stillbirth. Ensure you inform your medical carers of your condition so they can monitor your progress throughout your pregnancy. It's also a good idea to talk to your medical carers if you are planning a pregnancy to discuss potential risks and the best health plan for your pregnancy.

Birth trauma

Most stillbirths occur prior to labor, but there are circumstances when trauma suffered during labor causes a crucial reduction of oxygen to the baby, resulting in stillbirth. Shoulder dystocia, a breech delivery, or the umbilical cord becoming tightly wrapped around the baby's neck during delivery, are examples of how this may occur.

Infections

There are some infections which if undiagnosed or left untreated can pose a threat to the unborn child. For example, rubella, syphilis, and toxoplasmosis can all cause physical handicap or stillbirth.

Immunological disorders

Some disorders of the immune system are known to contribute to stillbirth. One such disorder is anti-phospholipid syndrome (APS), where the immune system interferes with normal blood clotting causing the placenta to fail to function - the clotting stops essential nutrients and oxygen from reaching the baby.