Screening should take place only in context of good quality controlled trials

EDITOR—Jarrett and Soares et al present arguments respectively against and in favour of screening for gestational diabetes.1 Jarrett has been arguing objectively against gestational diabetes as a useful concept for many years.2 In contrast, many obstetricians and diabetologists have aggressively sought and treated this condition despite a lack of real evidence. Rather, they have worked on the assumption that there is a continuum from normal glucose tolerance through gestational diabetes to frank diabetes and that gestational diabetes must be a less severe form of diabetes.

Screening for gestational diabetes presents a massive organisational and financial cost as well as a stressful burden to the women concerned. As Walkinshaw has shown, there is no evidence that attempts to control carbohydrate metabolism in women labelled as having gestational diabetes usefully alter perinatal outcome; rather, they lead to unnecessary interference.3 Had either Jarrett or Soares et al referred to Walkinshaw's systematic review then one of the three arguments of Soares et al for screening could have immediately been dismissed as lacking in supportive evidence. Their other two arguments are no more certain: that the …