The value of customised centiles in assessing perinatal mortality risk associated with parity and maternal size

Abstract

Objective We wanted to compare customised and population standards for defining smallness for gestational age (SGA) in the assessment of perinatal mortality risk associated with parity and maternal size.Design Population-based cohort study.Setting Sweden.Population Swedish Birth Registry database 1992-1995 with 354 205 complete records.Method Coefficients were derived and applied to determine SGA by the fully customised method, or by adjustment for fetal sex only, and using the same fetal weight standard.Main outcome measure Perinatal deaths and rates of small for gestational age (SGA) babies within subgroups stratified by parity, body mass index (BMI) and maternal size within the BMI range of 20.0-24.9.Results Perinatal mortality rates (PMR) had a U-shaped distribution in parity groups, increased proportionately with maternal BMI, and had no association with maternal size within the normal BMI range. For each of these subgroups, SGA rates determined by the customised method showed strong association with the PMR. In contrast, SGA based on uncustomised, populationbased centiles had poor correlation with perinatal mortality. The increased perinatal mortality risk in pregnancies of obese mothers was associated with an increased risk of SGA using customised centiles, and a decreased risk of SGA using population-based centiles.Conclusion The use of customised centiles to determine SGA improves the identification of pregnancies which are at increased risk of perinatal death.Keywords Body mass index, customised centiles, fetal growth restriction, intrauterine growth restriction, maternal size, parity, perinatal mortality, small for gestational age.Please cite this paper as: Gardosi J, Clausson B, Francis A. The value of customised centiles in assessing perinatal mortality risk associated with parity and maternal size.

Attention problems in relation to gestational age at birth and smallness for gestational age

“…However, some newborns are constitutionally small rather than growth restricted and their prognosis is less likely to be influenced by SGA status (32). We were unable to differentiate constitutionally small newborns from FGR newborns due to lack of data on prepregnancy maternal weight which is a crucial factor when defining constitutional smallness (33).…”

Author response to: Factors relating to a rising incidence of major postpartum haemorrhage

“…We read with interest the paper by Audureau et al 1 We note that following their interventions (prophylactic syntocinon, blood-collecting bags and sulprostone) that the incidence of major postpartum haemorrhage (PPH) did not significantly alter (0.81% in 2003 and 0.86% in 2005). Unfortunately, in our unit, a tertiary referral unit delivering about 5200 women a year, we identified a rise in the rate of PPH from 0.39% in 2003 to 0.66% in 2005, and then to 1.22% in 2008.…”

“…Audureau et al 1 defined major PPH as the presence of one or more of the following criteria: blood transfusion of at least one unit, surgery for uterine conservation, and hysterectomy. As suggested by Audureau et al, 1 it may be that their interventions did not alter the incidence of PPH because of an underlying rise in PPH that was prevented, or contained, by the interventions.…”

The role of ultrasound in the diagnosis and management of the growth restricted fetus

“…If the reference ranges for fetal biometric data and birth weight account for maternal height, weight, ethnicity, parity and fetal gender (thus better identifying fetal growth potential), the detection of IUGR is enhanced 6 . Growth potential percentiles have been shown to be superior to conventional reference ranges for the prediction of adverse perinatal outcome 7 , 8 . The GROW (gestation related optimal weight) software has customised data for different countries (including Australia), and is able to be downloaded from www.gestation.net.…”