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PAPERS:
James J. Newham, Simon H. Thomas, Karine MacRitchie, Patricia R. McElhatton, and R. Hamish McAllister-Williams
Birth weight of infants after maternal exposure to typical and atypical antipsychotics: prospective comparison study
The British Journal of Psychiatry 2008; 192: 333-337 [Abstract] [Full text] [PDF]
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[Read eLetter] Link between Birth weight, Gestational Diabetes, and atypical Antipsychotics
Geetha Desai, Prabha S. Chandra   (8 August 2008)

Link between Birth weight, Gestational Diabetes, and atypical Antipsychotics 8 August 2008
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Geetha Desai,
Consultant psychiatrist
Department of Psychiatry, NIMHANS,
Prabha S. Chandra

Send letter to journal:
Re: Link between Birth weight, Gestational Diabetes, and atypical Antipsychotics

desaigeetha{at}gmail.com Geetha Desai, et al.

The study by Newham et al1, found that 20 %, of babies of mothers on atypical antipsychotics were large for gestational age (LGA). While being a significant finding, it raises several methodological issues while clinically interpreting the data. The limitations (which the authors themselves mention) include lack of data on pre pregnancy maternal weight, weight gain during pregnancy and blood sugar levels during different trimesters, which may be important variables to predict risk for LGA infants. We would like to highlight one of the important risk factors for LGA, which is gestational diabetes, and here, lies the importance of screening for abnormal glucose tolerance in pregnancy, when mothers are on drugs like olanzapine. Some studies have reported that an abnormal glucose tolerance test, in pregnancy, even in the absence of overt diabetes maybe a significant risk factor for LGA babies2 . Abnormal glucose challenge tests in the mother at both 16 – 20 weeks and 26-30 weeks of pregnancy have been found to be more predictive of LGA infants than if found after 26 weeks alone3 . Women with bipolar disorders and schizophrenia are at increased risk of developing diabetes irrespective of exposure to antipsychotics. There are reports of women developing gestational diabetes following exposure to olanzapine even without weight gain4. A recent retrospective study of antipsychotics and birth outcomes has addressed the issue of gestational diabetes and large for gestational age in women exposed to antipsychotics5. While Newham et al’s study1 has alerted us to the risk of LGA with atypical antipsychotics, to help clinicians take meaningful decisions about atypical antipsychotic use in pregnancy, prospective studies will need to consider periodic screening tests for abnormal glucose metabolism (not only overt diabetes) during different trimesters of pregnancy. This might help us better predict which women might be at risk for development of LGA babies. It might also help in deciding which trimester use of atypical antipsychotics would be most risky for the mother and fetus.

Declaration of interests :None

1. Newham JJ, Thomas SH, MacRitchie K, McEllhatton PR, McAllister- Williams RH. Birth weight of infants after exposure of typical and atypical antipsychotics. prospective comparison study. Br J Psychiatry 2008; 192: 333-7

2. Jensen DM, Damm P, Sørensen B, Mølsted-Pedersen L, Westergaard JG, Klebe J, Beck-Nielsen H. Clinical impact of mild carbohydrate intolerance in pregnancy: a study of 2904 nondiabetic Danish women with risk factors for gestational diabetes mellitus. Am J Obstet Gynecol 2001; 185:413-9.

3. Mello G, Parretti E, Mecacci F, Lucchetti R, Lagazio C, Pratesi M, Scarselli G. Risk factors for fetal macrosomia: the importance of a positive oral glucose challenge test. Eur J Endocrinol 1997; 137:27-33. 4.Vermuri MP, Rasgon NL. A case of olanzapine-induced gestational diabetes mellitus in the absence of weight gain. J Clin Psychiatry 2007 Dec; 68:1989 5. Reis M, Kallini B. Maternal use of antipsychotics in early pregnancy and birth outcome. J Clin Psychopharmacol 2008; 28:279–88