in the active management group more patients returned to hospital with bleeding after discharge, and there was also a reduction in birthweight due to infants having a lower blood volume. the effects on the baby of early cord clamping was discussed in another review which found that delayed cord clamping improved iron stores longer term in the infants. although they were more likely to need phototherapy (light therapy) to treat jaundice, the improved iron stores are expected to be worth increasing the practice of delayed cord clamping in healthy term babies. for preterm babies (babies born before 37 weeks) a review of the research found that delaying cord clamping may lead to fewer babies with bleeding in the brain, compared to early cord clamping. another cochrane review looking at the timing of the giving oxytocin as part of the active management found similar benefits with giving it before or after the expulsion of the placenta. there is no good quality evidence on how best to treat a secondary pph (pph occurring 24 hrs or more after the birth). epidemiology methods of measuring blood loss associated with childbirth vary, complicating comparison of prevalence rates. a systematic review reported the highest rates of pph in africa (27.5%), and the lowest in oceania (7.2%), with an overall rate globally of 10.8%. the rate in both europe and north america was around 13%. the rate is higher for multiple pregnancies (32.4% compared with 10.6% for singletons), and for first-time mothers (12.9% compared with 10.0% for women in subsequent pregnancies). the overall rate of severe pph (>1000 ml) was much lower at an overall rate of 2.8%, again with the highest rate in africa (5.1%).