Aims To determine whether the neonatal and delivery outcomes of gestational diabetes vary seasonally in the context of a relatively cool temperate climate. Methods A retrospect cohort of 23 735 women consecutively delivering singleton, live‐born term infants in a single tertiary obstetrics centre in the UK (2004–2008) was identified. A total of 985 (4.1%) met the diagnostic criteria for gestational diabetes. Additive dynamic regression models, adjusted for maternal age, BMI, parity and ethnicity, were used to compare gestational diabetes incidence and outcomes over annual cycles. Outcomes included: random plasma glucose at booking; gestational diabetes diagnosis; birth weight centile; and delivery mode. Results The incidence of gestational diabetes varied by 30% from peak incidence (October births) to lowest incidence (March births; P=0.031). Ambient temperature at time of testing (28 weeks) was strongly positively associated with diagnosis (P<0.001). Significant seasonal variation was evident in birth weight in gestational diabetes‐affected pregnancies (average 54th centile June to September; average 60th centile December to March; P=0.027). Emergency Caesarean rates also showed significant seasonal variation of up to 50% (P=0.038), which was closely temporally correlated with increased birth weights. Conclusions There is substantial seasonal variation in gestational diabetes incidence and maternal–fetal outcomes, even in a relatively cool temperate climate. The highest average birth weight and greatest risk of emergency Caesarean delivery occurs in women delivering during the spring months. Recognizing seasonal variation in neonatal and delivery outcomes provides new opportunity for individualizing approaches to managing gestational diabetes.

The success of renal transplantation depends on lifelong immunosuppression. This can lead to a high incidence of avascular necrosis of major joints in the body for which arthroplasty is the treatment of choice. The risk of surgical complications is high in these patients, and there is no current set of cohesive perioperative management guidelines. In this review, we discuss the perioperative management of renal transplant patients undergoing elective total joint arthroplasty.

Objective: Gestational diabetes (GDM) incidence reportedly demonstrates seasonal variation. We aimed to assess if season also affects maternal-fetal outcomes in GDM. Methods: 23,735 women who consecutively delivered singleton, live-born, term infants in a tertiary obstetrics center (2004-08; 4.6% GDM) were included. Additive dynamic regression models (age, BMI, parity, ethnicity adjusted) compared GDM incidence and outcomes (GDM diagnosis, birth weight, delivery mode) over annual cycles. Results: GDM incidence varied by 30% from peak (October births) to nadir (March births; p&lt;0.05). Temperature at time of test (28 weeks) was strongly positively associated with diagnosis (p&lt;0.001). Birth weight in GDM-affected pregnancies showed marked seasonal variation (mean: 58th centile June - Sept; 67th centile Dec-Mar; p&lt;0.05; fig). Emergency Caesarean rates (50% variation, p&lt;0.05), closely temporally correlated with birth weight. Conclusions: Substantial seasonal variation exists in GDM diagnoses and maternal-fetal outcomes in GDM-affected pregnancies. Birth weight is highest when GDM diagnoses are lowest, implying either over-diagnosis in summer or more challenging glycemic control in winter. Considering seasonal variation gives new opportunities for intensive individualized therapy to improve outcomes. Figure: Effect of season on birthweight centiles in GDM; p&lt;0.05. Disclosure C.L. Meek: None. B.O. Devoy: None. D. Simmons: Speaker's Bureau; Self; Sanofi-Aventis. Other Relationship; Self; Medtronic. C. Patient: None. H.R. Murphy: Advisory Panel; Self; Medtronic MiniMed, Inc. C. Aiken: None. Funding Diabetes UK (17/0005712 to C.L.M.)