Maternal hyperthermia during pregnancy and cardiovascular malformations in the offspring

Abstract

During pregnancy, a number of factors predisposing to hyperthermia, such as sleeping in a water bed, sauna bathing, heatwave, high workplace temperature, and fever, are believed capable of harming the foetus. This study aimed to clarify possible associations of maternal workplace temperature, season of birth, sauna bathing, upper respiratory infection, and fever, with cardiovascular malformations in the offspring. The material was composed of all 573 cardiac malformations registered in Finland in 1982-84, and 1055 randomly chosen healthy controls. The mothers were interviewed at maternity welfare centers about three months after delivery. Fever (greater than or equal to 38 degrees C) during early pregnancy was more prevalent among case mothers (10%) than controls (6%) (p less than 0.01), largely manifest as increased risks of atrial septal defect and hypoplastic left heart. Upper respiratory infection was also more common among case mothers (26%) than controls (18%) (p less than 0.001). By contrast, maternal workplace temperature, sauna bathing, and temperature of the environment (seasonal variation) were not associated with risk of cardiac malformation in the offspring. The use of acetylsalicylic acid-containing medication for reducing fever was equally common (7%) among case and control mothers.

Health effects and risks of sauna bathing

“…No association was found between maternal sauna REVIEW bathing, the course of gestation, or the occurrence of congenital defects in a Finnish study (a three-year national material with about 500 cases and 1000 healthy control babies) (49). Similar results on the use of hot baths and sauna have been reported from New York (50).…”

Noninherited Risk Factors and Congenital Cardiovascular Defects: Current Knowledge

“…61 More recent studies suggest that other maternal febrile illnesses during the first trimester of pregnancy also may be associated with an increased risk for certain heart defects. 6,15,62,63 Mothers reporting any febrile illnesses during the first trimester of pregnancy have a 2-fold-higher risk of offspring with any heart defect in these studies. 6,15 Specific groups of defects that have been shown to be associated with maternal febrile illness include pulmonic stenosis, 6 all right-sided obstructive defects, 15 tricuspid atresia, 6,15 coarctation of the aorta, 15 all left-sided obstructive defects, 15 conotruncal defects, and VSDs.…”

High fever–related maternal diseases as possible causes of multiple congenital abnormalities: A population‐based case‐control study

“…First, the hyperthermia-induced isolated neural-tube defects were described (Chance and Smith, 1978;Miller et al, 1978;Layde et al, 1980;Shiota, 1982;Milunsky et al, 1992;Shaw et al, 1998;Medveczky et al, 2004;Á cs et al, 2005a,b). In addition, a higher risk for some other ICAs such as microcephaly , microphthalmia (Fraser and Skelton, 1978) Hirschprung disease (Lipson, 1988), CAs of the abdominal wall (Little et al, 1991), cardiovascular CAs (Tikkanen and Heinonen, 1991;Botto et al, 2001;Á cs et al, 2005a, CAs of the urinary tract (Abe et al, 2003), and orofacial cleft (Métneki et al, 2005;Á cs et al, 2005a was also found after high feverrelated maternal diseases. However, as far as we know, the possible association between high fever and MCAs in the human being has not been published.…”