Obese women beget obese children, who themselves become obese adults. Catalano and coworkers (2009) studied ofspring at a mean age of 9 years and found a direct association with maternal prepregnancy obesity and childhood obesity. hey also reported associations with central obesity, elevated systolic blood pressure, increased insulin resistance, and lipid abnormalities-all elements of the metabolic syndrome. Reynolds and associates (2013) reported higher rates of cardiovascular disease and all-cause mortality in 37,709 adult ofspring of overweight and obese mothers. Similar cardiometabolic health efects in ofspring were echoed by Gaillard and colleagues (2016). Other data support that excessive maternal weight gain in pregnancy may predict obesity in adult ofspring (Lawrence, 2014; Reynolds, 2010). Last, rates of glucose intolerance and metabolic syndrome are higher among ofspring of obese women (Gaillard, 2016; Tan, 2015).
he potential biological mechanisms of these associations are unclear. But such studies raise the possibility ofetal programming, that is, the fetal environment may lead to adverse adult health outcomes. Elucidation is limited by insuicient data on potential maternal and genetic predisposing factors and on the environment of the infant and child in relation to diet and activity. he science of epigenetics has provided some support for the possibility that perturbations of the maternal-fetal environment can adversely alter postdelivery events (Kitsiou-T zeli, 2017). Also possible are contributions of the maternal-child environment subsequent to birth (Gluck, 2009). These and other factors regarding fetal programming are discussed in Chapter 44 (p. 849).
The Institute of Medicine (2009) has updated its previous maternal weight gain determinants (Table 9-4, p. 166). For overweight women, weight gain of 15 to 25 pounds is sug gested. For obese women, the Institute advocates a gain of 11 to 20 pounds. Intuitively, maternal weight must increase suf iciently to provide for fetal and placental tissue accrual and for amnionic fluid and maternal blood volume expansion. Thus, maternal weight loss is during pregnancy is discouraged. The
American College of Obstetricians and Gynecologists (2015) endorses these Institute guidelines.
However, these recommendations were issued without irm scientific evidence to support them, and their value remains unproven (Rasmussen, 2010). For example, recent studies differ with respect to the efect of insuicient weight gain for obese women. Bodnar and colleagues (2016) reported no greater risk for low-birthweight or small-for-gestational-age newborns among 47,494 obese women who had inadequate weight gain during pregnancy. Bogaerts and associates (2015) found that even weight loss among obese women did not yield poor fetal growth. In contrast, however, Hannaford and coworkers (2017) reported that obese women who gained less than the Institute recommendations were almost three times more likely to deliver a small-for-gestational-age neonate. Another study similarly found an almost twofold greater risk among obese women who lost weight during pregnancy (Cox Bauer, 2016).