What are the current limits for prematurity?

HIGH PREVALENCE: Over the last 15 years, there has been a 2-fold rise in th e prevalence of early prematurity (birth before 33 weeks gestation) and ver y early prematurity (birth between 22 and 28 weeks gestation). More than 70 00 infants weighing between 500 g and 1500 g are born alive each year. Surv ival rates above 50% at 25 weeks, 86% at 29 weeks and 96% at 32 weeks are r eported. These infants have the same right to adapted care as any other per son. Nevertheless, maternal risks and the fact that these early and very ea rly premature infants account for less than 1% of all births and yet includ e 50% of all neonatal deaths and 50% of ail sequelae. A multidisicplinary a pproach is crucial for women with a high risk of delivery before 27 weeks g estation. ASSESSING PROGNOSIS: These infants comprise a very heterogeneous group of p atients. Their survival and prognosis depends on many different factors. An tenatal factors include gestational age, estimated fetal weight presence or not of malformations or fetal hypotrophy, and premature rupture of the mem branes. During the perinatal period, antenatal corticosteroid therapy, pre- birth referral to a maternity ward with a pediatric intensive care unit, an d care and degree of baro-trauma at delivery are essential. The neonatal as sessment may lead to discontinuing treatment in case of extensive neurologi cal damage. OPTIMAL CARE: With optimal care, achieved with an organized perinatal netwo rk using well-defined criteria for maternal referral, it should be possible to save 650 more children each year and reduce the number of severe handic aps by 390 among infants born before 33 weeks gestation. PREVENTION: Considerable progress has been made in perinatology, but simple and effective preventive measures must not be overlooked: reduction in the number of multiple pregnancies, detection of socio-demographic risk factor s, treatment of asymptomatic bacteriuria, early diagnosis of threatening pr emature birth. (C) 1999, Masson, Paris.