Maternal complications are most common during 3rd trimester and postpartum period:
Cerebral venous thrombosis, pneumonia, sepsis, pyelonephritis
Cerebral venous thrombosis, pneumonia, sepsis, pyelonephritis
Comorbid diseases in pregnancy
Abdominal pain in pregnancy
Vaginal bleeding in pregnancy 
Intrauterine device complications
First trimester abortion
Trauma in pregnancy
Pregnancy 
Preeclampsia