Infants and Children in Context. Tara L. Kuther

findings regarding the teratogenic effects of drugs are mixed, with some studies suggesting potential harm and others suggesting no ill effects of a given drug. For example, although high doses of the common painkiller aspirin may be associated with an increased risk of miscarriage and poor fetal growth (Li, Liu, & Odouli, 2003), low doses are often prescribed to pregnant women to prevent and treat high blood pressure and preeclampsia (dangerously high blood pressure late in pregnancy that can cause organ damage) (Roberge, Bujold, & Nicolaides, 2017). Likewise, the most common OTC drug consumed during pregnancy, caffeine, found in coffee, tea, cola drinks, and chocolate, appears to be safe in low doses (200 milligrams or about one cup per day; March of Dimes, 2015). Heavy caffeine consumption, however, is associated with an increased risk for miscarriage and low birthweight (Chen et al., 2014, 2016).

      Alcohol

      An estimated 10% to 20% of Canadian and U.S. women report consuming alcohol during pregnancy (Alshaarawy, Breslau, & Anthony, 2016; Popova, Lange, Probst, Parunashvili, & Rehm, 2017). Alcohol abuse during pregnancy has been identified as the leading cause of developmental disabilities (Webster et al., 2018). Fetal alcohol spectrum disorders refer to the continuum of effects of exposure to alcohol, which vary with the timing and amount of exposure (Hoyme et al., 2016). Fetal alcohol spectrum disorders are estimated to affect as many as 2% to 5% of younger schoolchildren in the United States and Western Europe (P. A. May et al., 2014, 2018). At the extreme end of the spectrum is fetal alcohol syndrome (FAS), a cluster of defects appearing after heavy prenatal exposure to alcohol. FAS is associated with a distinct pattern of facial characteristics (such as small head circumference, short nose, small eye opening, and small midface), pre- and postnatal growth deficiencies, and deficits in intellectual development, school achievement, memory, visuospatial skills, attention, language, problem solving, motor coordination, and the combined abilities to plan, focus attention, problem solve, and use goal-directed behavior (Gupta, Gupta, & Shirasaka, 2016; Wilhoit, Scott, & Simecka, 2017). The effects of exposure to alcohol within the womb persist throughout childhood and adolescence and are associated with cognitive, learning, and behavioral problems from childhood and adolescence through adulthood (Mamluk et al., 2016; Panczakiewicz et al., 2016; Rangmar et al., 2015).

      Fetal alcohol syndrome is associated with distinct facial characteristics, growth deficiencies, and deficits in physical and cognitive abilities that persist throughout childhood into adulthood.

      CC BY-SA 3.0

      Even moderate drinking is harmful, as children may be born displaying some but not all of the problems of FAS, termed fetal alcohol effects (Hoyme et al., 2016). Consuming 7 to 14 drinks per week during pregnancy is associated with lower birth size, growth deficits through adolescence, and deficits in attention, memory, and cognitive development (Alati et al., 2013; Flak et al., 2014; Lundsberg, Illuzzi, Belanger, Triche, & Bracken, 2015). Even less than one drink per day has been associated with poor fetal growth and preterm delivery (Mamluk et al., 2017). Sleeper effects may also occur with exposure to alcohol, as infants exposed prenatally to as little as an ounce of alcohol a day may display no obvious physical deformities at birth but later, as children, may demonstrate cognitive delays (Charness, Riley, & Sowell, 2016). Scientists have yet to determine if there is a safe level of drinking, but the only way to be certain of avoiding alcohol-related risks is to avoid alcohol during pregnancy altogether.

      Cigarette Smoking

      Every package of cigarettes sold in the United States includes a warning about the dangers of smoking while pregnant. Fetal deaths, premature births, and low birthweight are up to twice as frequent in mothers who are smokers than in those who do not smoke (Juárez & Merlo, 2013). Infants exposed to smoke while in the womb are prone to congenital heart defects, respiratory problems, and sudden infant death syndrome and, as children, show more behavior problems, have attention difficulties, and score lower on intelligence and achievement tests (He, Chen, Zhu, Hua, & Ke, 2017; Lee & Lupo, 2013; Sutin, Flynn, & Terracciano, 2017). Moreover, maternal smoking during pregnancy shows epigenetic effects on offspring, influencing predispositions to illness and disease in childhood, adolescence, and even middle adulthood (Joubert et al., 2016; Tehranifar et al., 2018). There is no safe level of smoking during pregnancy. Even babies born to light smokers (one to five cigarettes per day) show higher rates of low birthweight than do babies born to nonsmokers (Berlin, Golmard, Jacob, Tanguy, & Heishman, 2017; Tong, England, Rockhill, & D’Angelo, 2017). Although e-cigarettes are commonly believed to be “safer” than cigarettes, animal research suggests that exposure to e-cigarette vapor prenatally is associated with an increased risk for asthma and cognitive and neurological changes (T. Nguyen et al., 2018; Sharma et al., 2017). Research is sparse and just emerging, but it is likely that e-cigarettes have similar effects as smoking traditional cigarettes. Quitting smoking before or during pregnancy reduces the risk of adverse pregnancy outcomes.

      Cigarette packages in many countries include warnings of the dangers smoking poses to prenatal development.

      ©iStockphoto.com/Jan-Otto

      Cannabis

      The effects of cannabis, also referred to as marijuana, on prenatal development are not well understood because there are few long-term studies of its effects and existing studies vary both in quality and in conclusions (El Marroun et al., 2018). The main active ingredient of cannabis, tetrahydrocannabinol, or THC, readily crosses the placenta to affect the fetus in lower doses than experienced by the mother (Alvarez, Rubin, Pina, & Velasquez, 2018). Cannabis use during early pregnancy negatively affects fetal length and birthweight and is associated with a thinner cortex, the outer layer of the brain, in late childhood, suggesting that there are long-term neurological effects (El Marroun et al., 2016; Gunn et al., 2016). In fact, a growing body of research suggests that exposure to THC prenatally may lead to subtle long-term effects in cognition, including impairments in attention, memory, and executive function as well as impulsivity in children, adolescents, and young adults (Grant, Petroff, Isoherranen, Stella, & Burbacher, 2018; Sharapova et al., 2018; Smith et al., 2016). Researchers and health practitioners have thus concluded that it is important to educate the public about the impact of cannabis, even medical cannabis, on pregnancy (Chasnoff, 2017).

      Cocaine

      Prenatal exposure to cocaine is associated with low birthweight, impaired motor skills, and reduced brain volume at birth and in infancy (Grewen et al., 2014; Gupta, 2017). For example, 1 month after birth, babies who were exposed to cocaine have difficulty regulating their arousal states and show poor movement skills, poor reflexes, and greater excitability (Fallone et al., 2014). Prenatal cocaine exposure has long-term effects on children through its effect on brain development, particularly the regions associated with attention, arousal, regulation, and executive function (Bazinet, Squeglia, Riley, & Tapert, 2016).

      Although it was once believed that cocaine-exposed infants would suffer lifelong cognitive deficits, research suggests more subtle effects (Behnke & Smith, 2013; Lambert & Bauer, 2012). Prenatal cocaine exposure has a small but lasting effect on attention and behavioral control, as well as language skills through early adolescence (Buckingham-Howes, Berger, Scaletti, & Black, 2013; Lewis et al., 2013; Singer, Minnes, Min, Lewis, & Short, 2015). However, once home factors (such as parenting and socioeconomic status) are controlled, cocaine-exposed children do not show more behavioral problems in preschool and elementary school (Viteri et al., 2015). However, in adolescence, prenatal exposure to cocaine is associated with behavior problems and substance use (Min, Minnes, Yoon, Short, & Singer, 2014; Richardson, Goldschmidt, Larkby, & Day, 2015). The relationship between cocaine exposure and behavior problems in adolescence is reduced when contextual factors such as home caregiving