i am very sorry to hear about your daughter s loss. there can be many reasons why the baby died so prematurely in the womb, which is very rare in 29 weeks. anatomical defects of mother s womb, chromosomal anomalies, smoking, exposure to some medicines that are harmful to the baby or sometimes unknown problems can cause fetal death in 20 week gestation. i will suggest that she undergoes thorough investigations including a genetic counselling. unfortunately, you may never know the exact reason for the baby s death in womb. but preventive measures should help. she should ideally use a contraception for atleast 6 months before getting pregnant again. starting folic acid tablets early in pregnancy can be a preventive measure too.