A study in The BMJ found that women who had a complication -- such as placental abruption, preeclampsia, stillbirth, neonatal death and low birth weight for gestational age -- in their first pregnancy had a twofold higher risk for preterm birth in their second pregnancy, compared with those who had no complications. The findings, based on data involving over 302,000 women in Norway, also showed that the risk of preterm birth in a second pregnancy was three times higher in women who had two or more complications in their first pregnancy.