Although the role of such cytokines and chemokines in breast milk is unknown, they could possibly increase IgE production and/or stimulate a Th2 immune bias in infants. normal transition to a nonallergic immune response to inhaled allergens in her children, thus increasing the risk for the development of allergic sensitization and/or asthma. Understanding the underlying mechanisms by which the maternal immune environment can influence the development of the fetal-infant immune response to inhaled allergens may lead to identifying new targets for the prevention of allergic sensitization and asthma. Keywords: in utero, postnatal, immune, development, allergy, lung 1. Introduction A growing body of evidence suggests that the immunological changes leading to allergic diseases, such as asthma, start very early in childhood or even during pregnancy. Several lines of evidence further suggest that maternal exposure to allergens and/or the immune status of the mother, independent of a genetic contribution, may play a crucial role in the development-response of the fetal-infant immune system to inhaled allergens. Various studies have reported that children from allergic mothers are more likely to develop allergies/asthma than children from allergic fathers [1C8]. Infants of atopic mothers have an almost 5-fold higher probability of developing atopic dermatitis in comparison with children from atopic fathers [9]. Further, atopy in children is more closely associated with maternal asthma and IgE levels rather then paternal asthma and IgE [10C12]. This suggests that children from allergic mothers are exposed to a unique biological environment that may increase their risk for the development of asthma/allergies. However, the exact nature and mechanisms of this maternal influence and how it might be associated with the development of allergic sensitization and asthma are not clear. 2. Prevalence of asthma during pregnancy In concert with the increasing incidence of asthma in the general population, the Diclofenac diethylamine number of females with asthma during pregnancy is also increasing. Recent estimates from a review of U.S. health surveys covering the years 1997 C 2001 indicate that between 3.7% C 8.4% of pregnant females had asthma [13]. That is an increase from 3.2% for the years 1988 C 1994 [13]. Even higher rates of asthma, 12.4%, have been reported in pregnant woman from Western Australia, with 8.8% reporting exacerbation of Diclofenac diethylamine symptoms or the use of asthma medication during pregnancy [14]. Asthma is the most common respiratory disorder that may complicate pregnancy and potentially impact fetal/infant immune ABH2 development. 3. Effects of maternal asthma on pregnancy Asthma can have serious effects on the outcome of a pregnancy, and conversely, pregnancy can alter the clinical status of the pregnant female with asthma (reviewed [15, 16]). While there are conflicting results amongst the many studies examining the relationship between asthma and pregnancy outcomes, the general consensus is usually that asthmatic females are at greater risk of low birth weight neonates, preterm neonates, cesarean delivery, and complications such as preeclampsia. Further, the poorest outcomes appear to be associated with females with uncontrolled asthma [16, 17]. Changes in asthma symptoms brought about by pregnancy are unpredictable on an individual basis; but a general paradigm that asthma will worsen in one-third, remain the same in one-third, and improve in-one-third of the women has been accepted for years. Whether these effects additionally alter long-term outcomes in offspring is not clear, but they likely share some common mechanisms. Several mechanisms associated with the adverse effects of Diclofenac diethylamine maternal asthma on pregnancy outcomes have been postulated and may include maternal hypoxia, inflammation, corticosteroid treatment, smoking, exacerbation of asthma, fetal sex, and altered placental function. Most direct evidence centers on the stimulation/control of inflammatory responses and placental factors. Reduced birth weight has been correlated with those asthmatics that have had at least one asthma attack during pregnancy (i.e., exacerbation of asthma) [18, 19]. In a study by Murphy et al. [20] maternal asthma severity, inflammation, lung function,.