OBJECTIVE:To examine the maternal and foetal risks of adverse pregnancy outcome in relation to maternal obesity, expressed as body mass index (BMI, kg=m 2 ) in a large unselected geographical population. DESIGN: Retrospective analysis of data from a validated maternity database system which includes all but one of the maternity units in the North West Thames Region. A comparison of pregnancy outcomes was made on the basis of maternal BMI at booking. SUBJECTS: A total of 287 213 completed singleton pregnancies were studied including 176 923 (61.6%) normal weight (BMI 20 -24.9), 79 014 (27.5%) moderately obese ) and 31 276 (10.9%) very obese (BMI ! 30) women. MEASUREMENTS: Ante-natal complications, intervention in labour, maternal morbidity and neonatal outcome were examined and data presented as raw frequencies and adjusted odds ratios with 99% confidence intervals following logistic regression analysis to account for confounding variables. RESULTS: Compared to women with normal BMI, the following outcomes were significantly more common in obese pregnant women (odds ratio (99% confidence interval) for BMI 25 -30 and BMI ! 30 respectively): gestational diabetes mellitus (1.68 (1.53 -1.84), 3.6 (3.25 -3.98)); proteinuric pre-eclampsia (1.44 (1.28 -1.62), 2.14 (1.85 -2.47)); induction of labour (2.14 (1.85 -2.47), 1.70 (1.64 -1.76)); delivery by emergency caesarian section (1.30 (1.25 -1.34), 1.83 (1.74 -1.93)); postpartum haemorrhage (1.16 (1.12 -1.21), 1.39 (1.32 -1.46)); genital tract infection (1.24 (1.09 -1.41), 1.30 (1.07 -1.56)); urinary tract infection (1.17 (1.04 -1.33), 1.39 (1.18 -1.63)); wound infection (1.27 (1.09 -1.48), 2.24 (1.91 -2.64)); birthweight above the 90th centile (1.57 (1.50 -1.64), 2.36 (2.23 -2.50)), and intrauterine death (1.10 (0.94 -1.28), 1.40 (1.14 -1.71)). However, delivery before 32 weeks' gestation (0.73 (0.65 -0.82), 0.81 (0.69 -0.95)) and breastfeeding at discharge (0.86 (0.84 -0.88), 0.58 (0.56 -0.60)) were significantly less likely in the overweight groups. In all cases, increasing maternal BMI was associated with increased magnitude of risk. CONCLUSION: Maternal obesity carries significant risks for the mother and foetus. The risk increases with the degree of obesity and persists after accounting for other confounding demographic factors. The basis of many of the complications is likely to be related to the altered metabolic state associated with morbid obesity.

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Objective To assess the validity of clinical information held on a regional maternity database, the St Mary's Maternity Information System (SMMIS). Design A retrospective review of 892 maternity case notes and matched SMMIS records, by a midwife trained in clinical coding techniques. Setting Three maternity units in the North West Thames Region. Main outcome measures Percentage agreement for 17 directly recorded SMMIS data items and equivalent data abstracted from the notes. Frequencies of diagnosis codes abstracted from case notes, as compared with those generated by SMMIS on the basis of directly recorded data. Results A generally high level of agreement was observed between the abstracts of the notes and the SMMIS records. Of the 17 data items examined, 10 showed 95% agreement or better, and all but two exceeded 80% agreement. Little difference was found between the levels of agreement observed at the three sites. A greater number and range of diagnosis codes were abstracted from the notes than were generated by SMMIS. Conclusions The directly recorded clinical data held on the SMMIS regional database is largely accurate and consistently recorded across a variety of units. The database can therefore be considered a valuable resource for the comparative audit of maternity practice. The SMMIS technique for deriving, on a semi‐automatic basis, diagnosis codes from the directly recorded fields, appears to work moderately well. We suggest that the direct method of data collection used in SMMIS could provide a model for other specialties in the National Health Service.

AND SummaryA comparison between data derived from changes in fetal heart rate and p H of fetal blood in 279 high-risk patients is described. 'The incidence of fetal acidosis was low when the continuous record of FHR showed good beat-to-beat variation in rhythm and no slowing during uterine contractions. The incidence of fetal acidosis accompanying fetal tachycardia or bradycardia was low if the rate remained unaltered during contractions. Decelerations of fetal heart rate accompanied by baseline tachycardia and/or loss of beat-to-beat variation were the changes most commonly associated with fetal acidosis and hence, by inference, with fetal asphyxia. Deep and/or delayed decelerations were also suggestive of fetal asphyxia. Late decelerations, although at first sight innocuous, were frequently found to be a sign of severe fetal asphyxia.

AND SummaryA comparison between data derived from changes in fetal heart rate and p H of fetal blood in 279 high-risk patients is described. 'The incidence of fetal acidosis was low when the continuous record of FHR showed good beat-to-beat variation in rhythm and no slowing during uterine contractions. The incidence of fetal acidosis accompanying fetal tachycardia or bradycardia was low if the rate remained unaltered during contractions. Decelerations of fetal heart rate accompanied by baseline tachycardia and/or loss of beat-to-beat variation were the changes most commonly associated with fetal acidosis and hence, by inference, with fetal asphyxia. Deep and/or delayed decelerations were also suggestive of fetal asphyxia. Late decelerations, although at first sight innocuous, were frequently found to be a sign of severe fetal asphyxia.