Evaluating perinatal death rates, Lindam and coworkers (2016) reported that high maternal BMI in early pregnancy was a risk factor. The risk ofneonatal death is also greater for obese women 0ohansson, 2014; Meehan, 2014). Finally, Cnattingius and Villamor (2016) noted that accruingweight between pregnancies is a risk factor for perinatal mortality, whereas weight loss between pregnancies for overweightwomen lowers this risk.
Both fetal and neonatal complications are increased in obese women. Two important and interrelated cofactors that 0.85 • Obese
J 0.80 0.75 .J,0.70 .J,0.65 0.60
FIGURE 48-7 Geometric changes of ventricular remodeling across pregnancy in obese and normal-weight women. LVM = left ventricular mass, LVEDV = left ventricular end-diastolic volume. (Data from Stewart, 2016.) contribute to excessive rates of perinatal morbidity are chronic hypertension and diabetes, both of which are associated with maternal obesity. hese comorbidities each may playra role in the higher rates of fetal-growth restriction and indicated pre term birth that are seen in obese women (Schummers, 2015).
Pregestational diabetes also raises the birth defect rate, and ges tational diabetes is complicated by excessive numbers of large for-gestational-age and macrosomic fetuses (Chap. 44, p. 857).
Even when diabetes is not considered, the prevalence of macrosomic newborns is greater in obese women (Kim, 2016;
Ovesen, 2011; Schummers, 2015). he group from Metro prepregnancy obesity, gestational weight gain, and diabetes and their relationship to adverse pregnancy outcomes and to greater newborn weight and fat mass (Catalano, 2009, 2015; Lassance, 2015; Ma, 2016; Yang, 2016). Although each of these variables is associated with larger and more corpulent newborns, pre gene expression has the strongest influence on the prevalence of macrosomic neonates.
Rates of birth defects are also higher with comorbid obesity (Stothard, 2009). For neural-tube defects, elevated risks of 1.2-, 1.7-, and 3. I-fold are found in overweight, obese, and severely obese women, respectively (Rasmussen, 2008). he National Birth Defect Prevention Study reported a correlation between BMI and congenital heart defects (Gilboa, 2010). However, this may be related to diabetes as a cofactor (Biggio, 2010). Importantly, obesity is detrimental to the accuracy of obstetrical sonographic examination and to antepartum identiication of birth defects (Adekola, 2015; Dashe, 2009; Weichart, 2011).