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PAPERS: Jerónima M A Teixeira, Nicholas M Fisk, and Vivette Glover Association between maternal anxiety in pregnancy and increased uterine artery resistance index: cohort based study BMJ 1999; 318: 153-157 [Abstract] [Full text]

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Maternal stress and the unborn child

Tom Oommen   (15 January 1999)

Migraine & effects on Foetus

Amit Kumar   (22 January 1999)

Maternal blood pressure, social class and weight were not considered as potential confounders

Rachel Bennett   (13 February 1999)

Maternal stress and the unborn child 15 January 1999
Tom Oommen, Asst.Professor in Pharmacology Kasturba Medical College, Manipal, India Send response to journal: Re: Maternal stress and the unborn child	Reduced blood flow through the uterine arteries, which may be caused by stress or anxiety, could partialy explain why women who are anxious during pregnance tend to have smaller babies (1). It is now known that hormonal changes cause changes in the uterine vasculature in a specific and complex way in order to cope with nidation and pregnancy. Hormonal changes also influence the innervation of the arteries and influence spontaneous contractility of the vessel walls (2). The basic and abundant adrenergic and cholinergic nerve supply to the human uterine arteries, mediating both conraction and relaxation, have been well documented. The post-junctional adrenoceptors are primarily of the alpha-1 type (3). The smooth muscles of the vessel walls of the uterine arteries contain peptidergic nerves which also mediate both contraction and relaxation. Immunohistochemical studies demonstrate separate fibres containing vasoactive intestinal peptide, histidine, methionine, neuropeptide Y, and to some extent leuenkephalin (4). Therefore the regulation of endometrial blood flow is complex, involving adrenergic and peptidergic nerves and humoral factors. Hormonal factors also influence innervation. The smaller (resistance) branches of the uterine arteries appear to be of particular importance in the regulation of uterine blood flow since they are the most densely innervated. Considerable pre-clinical research has shown that stress can result in functional and morphological changes within the hippocampus. It is now well accepted that stress-induced elevation of glucocorticoids augments the extra-cellular accumulation of excitatory aminoacids such as glutamate, resulting in hippocampal damage, which has been evident from both cytoarchitectural and functional perspectives (5). It has also been suggested that trauma (in this case, maternal anxiety) may alter neuroanaomy (6). Therefore stress and anxiety affect fetal development through several possible mechanisms. Further research could be directed towards management of maternal anxiety without any risk to the unborn child since abortions predispose to the post-abortion syndrome which could aggravate the psychological state of the mother. As Sigmund Freud said, biology is truly a land of unlimited possibilities. We may expect it to give us the most surprising information and we cannot guess what answers it will return in a few dozen years to the questions we have put! References: 1. Teixeira JMA, Fisk NM, Glover V. Association between maternal anxiety in pregnancy and increased uterine artery resistance index: cohort based study. BMJ 1999; 318: 153-57 2. Akerlund M. Vascularisation of human endometrium: uterine blood flow in healthy condition and in primary dysmenorhoea. Ann. New York Acad. Sci. 1994; 734: 47-56 3. Stjernquist M, Owman C. Adrenoceptors mediating contraction in human uterine artery. Human reprod. 1990; 5: 19-24 4. Ekesbo R, Alm P, Bossmar T. Differences in innervation between main stemand smaller branches. (Quoted in Ref. 2) 5. Moghaddam , Bolinao ML, Stein-Berhens B, Sapolisky R. Glucocorticoids mediate the stress-induced extracellular accumulation of glutamate. Brain Res. 1994; 65: 251-254 6. Stein MB, Hanna C, Koverola C, et al. Structural brain changes in posttraumatic stress disorder: does trau alter neuroanatomy? Ann. Ney York Acad. Sci. 1997; 821: 76-82
Migraine & effects on Foetus 22 January 1999
Amit Kumar, SHO Anaesthetics North Tees General Hospital, Stockton on Tees, UK Send response to journal: Re: Migraine & effects on Foetus	I am interested to find out if episodes of migraine and the stress associated with it has any adverse effects on the growing foetus. Are there any vasospastic events in the rest of the body or more specifically in the uterine vessels during the migraine episode or its prodromal period? Are there any significant hormonal changes during such severe stress that might affect the foetal growth?
Maternal blood pressure, social class and weight were not considered as potential confounders 13 February 1999
Rachel Bennett Send response to journal: Re: Maternal blood pressure, social class and weight were not considered as potential confounders	Editor- The role of fetal programming in the development of chronic life disease is an exciting field of interest. But it is one which lacks good evidence from human studies of the underlying biological mechanisms involved. I was interested therefore to read Teixeira et al's study which suggests that reduced uterine blood flow could explain why woman who are anxious in pregnancy have smaller babies1. However it was disappointing that the study failed to consider three important potential confounders. Namely; maternal blood pressure, social class, and weight. Recent work based on twenty-four hour ambulatory blood pressure in pregnancy shows evidence of a continuous inverse association between maternal blood pressure across the normal range and fetal growth 2. Teixeire et al excluded women with pre eclampsia from their study and comment that all women had 'normal' blood pressure at the time of doppler examination. However they failed to include blood pressure within the normal range as a potential confounder. In view of the obvious association between blood pressure and anxiety, as well as evidence of restricted uterine blood flow, all be it in pre-eclamptic woman 3, I was surprised at this omission. Studies have shown that low birth weight babies are more likely to be born into families of low socio-economic status 4. The reasons for this are probably multi factoral, including both biological and social influences. Woman in lower socio-economic groups are also more likely to experience stress and anxiety due to factors such as low income, single parenthood and larger family size. Teixeira et al looked at the number of recent life events experienced by the woman in their study but not at her social class. Finally, although perhaps less important, is maternal weight. Studies have shown that women who have low body weight before pregnancy have smaller babies5. It is possible that chronic anxiety could lead to weight loss and thus be more prevalent amongst women of lower body weight. In this way maternal body weight could act as a confounder in this study. In view of the simplicity of measuring these three potential confounding variables I was surprised at their omission. Nevertheless the study adds valuable information to our understanding of this relatively new field of interest. Dr Rachel Bennett, SHO General Medicine, presently studying at The London School Of Hygiene and Tropical Medicine, 20 Kellett Road, Brixton, London SW2 1EB 1 Teixeira JMA, Fisk NM, Glover V. Association between maternal anxiety in pregnancy and increased uterine artery resistance index:cohort based study. BMJ 1999;318:153-157. 2 Chuchill D, Perry IJ, Beevers DG. Ambulatory blood pressure in pregnancy and fetal growth. Lancet 1997;349:7-10. 3. Taylor DJ. The epidemiology of hypertension during pregnancy. In: Rubin PC, ed. Handbook of hypertension Vol.10; Hypertension In Pregnancy.In: reference 4. 4. Kuh D, Ben-Shlomo Y, eds. A life course approach to chronic disease epidemiology. Oxford university Press1997;173. 5. Love EJ, Kinch RAH. Factors influencing the birth weight in normal pregnancy. In: Barker DJP. Mothers, babies and health in later life. Churchill Livingstone 1998;136.