Definition of Prematurity

ubetween the 22nd gestational week (> 154 days p.m.) and 37 completed weeks (< 259 days p.m.)ÞThis roughly correspondends to a birth weight 500 – 2,500 g

Note: menstrual dating may be inaccurate in up to 20%

  gestation should be estimated on the best clinical way including ultrasound

Much epidemiological work uses birthweight as a standard:

llow birthweight (< 2501 g)

lvery low birthweight (< 1501 g)

lextremely low birthweight (< 1000 g) *

* WHO recommendation: registration of all births over 500 g

What is the Problem in Prematurity?


uneonates with birth weights of less than 2,500 g comprise

up to 80% of perinatal mortality in developed nations

ua child with birth weight < 1,500 g has 200-fold increased

risk of death compared to a child weighing over 2,500 g

last 20 years: marked increase in survival

of infants < 1500 g:

luse of corticosteroids

lregionalization of perinatal care

limproved methods of mechanical ventilation

lavailability of exogenous surfactant

limproved nutritional therapy


urespiratory distress syndrome (RDS) /

bronchopulmonary dysplasia (BPD)

uintracranial hemorrhage, periventricular leucomalacia

(® cerebral palsy)

Note: 50 % of all major neurologic handicaps in

children result from premature births

upersistent patent ductus arteriosus

uhypothermia, hypoglycemia, apnea, bradycardia

uincreased risk of infection

Prematurity and its consequences

remain a major health problem!

The key to a successful management is a well-

structured and comprehensive set of guidelines:

l  diagnosis

l  therapy

l  delivery

Major Preterm Labor Risks:


relative risk

uprior preterm birth              6 – 8

uprior preterm birth < 28 weeks        10

umultiple gestations                6 – 8

ulow socioeconomic status               2 – 2.5

The strongest predictor of preterm birth

is previous preterm birth!

The more preterm the first birth,

the less likely the subsequent pregnancy

is go to term.

Modifiable                              Nonmodifiable

– poor maternal weight gain           – extremes of age (<17 or >40 years)

– physically demanding work           – history of uterine abnormality

– smoking                             – placenta previa

– anemia                             – low prepregnancy weight

– bacteruria

– bacterial vaginosis

– maternal systemic infections

(e.g., pyelonephritis)

Four major categories

uPPROM (preterm premature rupture of mambranes)

uuncomplicated spontaneous preterm delivery

uelective preterm delivery for severe maternal or fetal

medical conditions (e.g., alloimmunisation, IUGR)

ucomplicated emergency delivery (e.g., placenta previa,

abruptio placenta.

Prediction of Preterm Delivery/ Diagnostics


Assessment of risk of preterm delivery should be

a formal part of each antenatal visit.

concentrate on identification of modifiable risk factors:

– life style, stress, working pattern

– weight, smoking, drugs

– urinary and vaginal infection

uuse key non-modifiable demographic, past reproductive

history and current pregnancy risk factors to consider

secondary screening by ultrasound or biochemistry