Child Development From Infancy to Adolescence. Laura E. Levine
Women who are using illegal drugs may be less likely to see a doctor during their pregnancy and are less likely to take good care of themselves in other ways. We cannot review here all the illegal substances that might be used by a pregnant woman but we briefly look at research that has been done on two of the more commonly used substances: cocaine and marijuana.
The well-documented effects of cocaine use include complications during the pregnancy itself and an increased probability of the infant being born prematurely, at low birth weight, or small-for-gestational age (Forray & Foster, 2015; Ross, Graham, Money, & Stanwood, 2015). The effect on other developmental outcomes, including cognitive, motor, and language development, has been inconsistent. Some studies report significant effects, but others report no or only small effects (Forray & Foster, 2015). It is likely that differences that mitigate or worsen effects of the prenatal exposure to the drug, such as the quality of the infant and child’s living environment, are responsible for this variability. Although prenatal exposure to cocaine has not consistently been associated with lower overall cognitive ability, research continues to examine the impact on more subtle aspects of cognitive functioning in later childhood and adolescence, including impairment in attention, working memory, information processing, and problem-solving skills (Ross et al., 2015).
The psychoactive ingredient in marijuana crosses the placenta barrier during pregnancy and enters the bloodstream of the fetus, where it can result in stunted physical growth and decreased birth weight (Ross et al., 2015). After birth, prenatal exposure to marijuana has been associated with learning disabilities and memory impairment in young children; impulsivity, hyperactivity, inattention, and poor problem-solving skills in school-age children; and hyperactivity, inattention, and lack of self-control and emotional regulation in adolescents (Ross et al., 2015; Wu, Jew, & Lu, 2011). A possible explanation for these findings is that cannabis alters the neurology in the prefrontal cortex, the site in the brain responsible for higher cognitive functioning that develops later in childhood (Huizink & Mulder, 2006). Prenatal exposure also may change brain circuits in ways that make the rewarding effect of the drug even stronger. This idea is supported by several longitudinal studies that have found that prenatal maternal use of marijuana predicted the likelihood of adolescents beginning to use the drug themselves (Porath & Fried, 2005; see also Jutras-Aswad, DiNieri, Harkany, & Hurd, 2009), lowered the age at which they began using, and increased the frequency of use (Day, Goldschmidt, & Thomas, 2006). Despite the number of negative developmental outcomes that have been associated with maternal use of marijuana, our current research may actually underestimate the long-term effects of the drug on children because the concentration of the active compound in marijuana today is much higher than when many earlier studies were done.
T/F #6
Children who were exposed to marijuana prenatally are more likely to smoke marijuana when they become teenagers. True
Although marijuana has been legalized for recreational or medicinal use in some states, and although there are some recognized medical uses for it, the American Congress of Obstetricians and Gynecologists (2015) recommends that doctors ask pregnant women about their use of marijuana when asking about their use of alcohol and tobacco and urge them to discontinue its use while pregnant and nursing. For marijuana sold through legitimate channels, the American Medical Association (2016) has called for point-of-sale warning labels on marijuana, similar to those used on alcoholic beverages and tobacco products, to warn pregnant women about the risk of using the product.
A pregnancy offers a woman the opportunity to decrease or even discontinue her substance use, but similar to the situation with smoking, many resume use following the birth of their infant (Bailey, Hill, Hawkins, Catalano, & Abbott, 2008; Koniak-Griffin, Spears, & Stein, 2010), with the youngest mothers being the ones who are more likely to resume using (De Genna, Cornelius, Goldschmidt, & Day, 2015). Returning to using marijuana is a concern because the active compound in cannabis is present in breast milk, so the infant’s developing brain is further exposed to this substance. As you will learn in Chapter 15, young people increasingly do not see this drug as harmful, which means that in the future children with a possible neurological sensitivity to marijuana because of their prenatal exposure may also have parental role models who engage in this behavior. Women need to think carefully about these consequences before using recreational drugs.
A study that compared the independent effects of alcohol, tobacco, cocaine, and marijuana on the likelihood of a preterm delivery or restricted fetal growth concluded that the legal substances, alcohol and tobacco, were more harmful than the illegal ones (Janisse, Bailey, Ager, & Sokol, 2014). This research serves as a reminder that the legal-illegal distinction should not be equated with the harmfulness of a substance. Figure 4.6 summarizes some of the outcomes of drug and alcohol use.
Figure 4.6 Effects of prenatal drug exposure.
Source: Ross, E. J., Graham, D. L., Money, K. M., & Stanwood, G. D. (2015). Developmental Consequences of Fetal Exposure to Drugs: What We Know and What We Still Must Learn. Neuropsychopharmacology, 40(1), 61–87. Reprinted with permission from Macmillan Publishers, Ltd.
Diseases
In this section, we discuss several common diseases and medical conditions that can have a detrimental effect on a pregnancy. Screening for sexually transmitted infections (STIs) is a routine part of prenatal care. Some STIs can cross the placenta and infect the baby prenatally, and others are present in the birth canal and can infect the baby during the birth process (USDHHS, 2015c). While bacterial infections such as chlamydia, gonorrhea, and syphilis can be treated and cured with antibiotics during the pregnancy, viral STIs such as genital herpes and HIV cannot be cured, although antiviral medication can reduce the symptoms and their effect on the fetus (CDC, 2016p).
The virus that causes HIV is one that can be transmitted during the pregnancy by crossing the placental barrier, picked up in the birth canal when the baby is delivered vaginally, or passed through the mother’s breast milk after the baby is born. That is why it is recommended that HIV-positive mothers deliver their babies through a planned cesarean section and not breastfeed their infants (AIDSinfo, 2017). Taking antiviral medication while pregnant lowers the viral load in the woman’s blood. If she takes HIV medication throughout her pregnancy and her infant is treated for 4 to 6 weeks after birth, the infection risk for the infant can be 1% or less (CDC, 2017i).
A newly recognized threat to a healthy pregnancy is Zika, a disease caused by a virus transmitted by an infected mosquito or through unprotected sex with an infected partner (European Centre for Disease Prevention and Control, 2017). In healthy adults, the infection is mild and may cause a fever, rash, muscle pain, or headaches, or may produce no symptoms at all (CDC, 2016q), but when a pregnant woman becomes infected, the virus is transmitted through the placenta where it disrupts fetal brain development, resulting in microcephaly, a birth defect in which the newborn’s head is abnormally small and the brain is underdeveloped (CDC, 2017t). Microcephaly is associated with seizures, intellectual disability, vision and hearing problems, and a range of developmental delays (CDC, 2016j).
Microcephaly: A birth defect in which the newborn’s head is abnormally small and the brain is underdeveloped.
Fortunately, there are recent signs of a significant slow-down of the epidemic in the Americas and the Caribbean (European Centre for Disease Prevention and Control, 2017), but pregnant women are still warned to try to avoid being bitten by mosquitos and to use condoms with partners who may be infected with the virus. A vaccine is in development, but is not yet available to the public (National Institute of Allergy and Infectious Diseases, 2017).
Microcephaly. Exposure to the Zika virus during pregnancy is associated with