 Preterm delivery, defined as delivery before 37 weeks of completed gestation 259 days, is a major cause of neonatal morbidity and mortality. Despite extensive research, preterm birth still accounts for 5-10 of all deliveries in developed countries and rates are on the increase, including in the UK. While mortality associated with preterm delivery has declined due to use of antenatal steroids and improvements in neonatal intensive care, preterm babies still remain at risk of major complications. These include respiratory distress syndrome, necrotising enterocolitis, retinopathy of prematurity, sepsis, intraventricular haemorrhage, periventricular leucomalacia and long-term cognitive and sensory impairment. Two major determinants for the mortality and morbidity of babies born preterm are gestation at delivery and birthweight. Prematurity therefore carries significant cost implications to both healthcare services and society in general. High hemoglobin along with anemia was examined in an observational study. At entry to care, which ranged between 6 and 8.4 wk gestation, women with hemoglobin levels exceeding 130gL had a greater than twofold increase in risk of preterm delivery and infant low birth weight. Neither risk was statistically significant, however, because of the small numbers with high hemoglobin. Similarly, a concentration of the iron storage protein, ferritin, that is high for the third trimester of pregnancy is also associated with an increased risk for preterm and very preterm delivery. Over the last twenty years, interest has been shown in using ultrasound parameters or Doppler studies of fetal blood to assess fetal anaemia. Middle cerebral artery Doppler has taken over and has replaced amniocentesis as a screening test for fetal anaemia in high risk pregnancies. 