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.

Many human conceptions are genetically abnormal and end in miscarriage, which is the commonest complication of pregnancy. Recurrent miscarriage, the loss of three or more consecutive pregnancies, affects 1% of couples trying to conceive. It is associated with psychological morbidity, and has often proven to be frustrating for both patient and clinician. A third of women attending specialist clinics are clinically depressed, and one in five have levels of anxiety that are similar to those in psychiatric outpatient populations. Many conventional beliefs about the cause and treatment of women with recurrent miscarriage have not withstood scrutiny, but progress has been made. Research has emphasised the importance of recurrent miscarriage in the range of reproductive failure linking subfertility and late pregnancy complications and has allowed us to reject practice based on anecdotal evidence in favour of evidence-based management.

Treatment with aspirin and heparin leads to a significantly higher rate of live births in women with a history of recurrent miscarriage associated with phospholipid antibodies than that achieved with aspirin alone.

Miscarriage is generally defined as the loss of a pregnancy before viability. An estimated 23 million miscarriages occur every year worldwide, translating to 44 pregnancy losses each minute. The pooled risk of miscarriage is 15•3% (95% CI: 12•5% -18•7%) of all recognised pregnancies. The population prevalence of women with one miscarriage is 10•8% (95% CI 10•3% -11•4%), two miscarriages is 1•9% (95% CI 1•8% -2•1%) and three or more miscarriages is 0•7% (0•5% -0•8%).Risk factors for miscarriage include very young or older female age, older male age, very low or very high body mass index, black ethnicity, previous miscarriages, smoking, alcohol, stress levels, night shift working, air pollution and exposure to pesticides. The consequences of miscarriage are both physical, such as bleeding or infection, and psychological.Psychological consequences include increases in the risk of anxiety, depression, post-traumatic stress disorder and suicide. Miscarriage, and especially recurrent miscarriage, is also a sentinel risk marker for obstetric complications, including preterm birth, fetal growth restriction, placental abruption and stillbirth in future pregnancies, and a predictor of longer-term health problems, such as cardiovascular disease and venous thromboembolism.The costs of miscarriage affect individuals, healthcare systems and society at large. The short-term national economic cost of miscarriage is estimated to be £471 million per year in the United Kingdom. As recurrent miscarriage is a sentinel marker for various obstetric risks in future pregnancies, women should receive care in pre-conception and high-risk obstetric clinics. As psychological morbidity is common after pregnancy loss, effective screening instruments and treatment options for mental health consequences of miscarriage need to be available. We recommend that miscarriage data are gathered and reported to facilitate comparison of rates amongst countries, to accelerate research, and to improve patient care and policy development.