Which factor is NOT associated with a significantly higher incidence of pregnancy-induced hypertension (PIH) compared with a healthy 25-year-old primigravida?

Which factor is NOT associated with a significantly higher incidence of pregnancy-induced hypertension (PIH) compared with a healthy 25-year-old primigravida?

• A. Young primigravida (<20 years)
• B. Multiple gestation
• C. Diabetes mellitus type I
• D. Smoking (>1 pack/day)

Answer: (D)

Pregnancy-induced hypertension tends to rise with factors that impair placental development and maternal vascular adaptation. Being younger than 20 years and carrying a first pregnancy both heighten the risk because of immature or relatively adverse placental implantation and vascular responses. Having multiple gestation increases risk due to a larger placental mass and greater hemodynamic stress. Preexisting type I diabetes adds risk through chronic vascular and endothelial changes that predispose to hypertensive disorders. In contrast, smoking during pregnancy does not raise the incidence of PIH; in fact, many studies show a lower observed rate of preeclampsia among smokers, although smoking clearly worsens other pregnancy outcomes such as fetal growth restriction and placental abruption. Thus, smoking is not associated with a significantly higher PIH incidence.

Pregnancy-induced hypertension tends to rise with factors that impair placental development and maternal vascular adaptation. Being younger than 20 years and carrying a first pregnancy both heighten the risk because of immature or relatively adverse placental implantation and vascular responses. Having multiple gestation increases risk due to a larger placental mass and greater hemodynamic stress. Preexisting type I diabetes adds risk through chronic vascular and endothelial changes that predispose to hypertensive disorders. In contrast, smoking during pregnancy does not raise the incidence of PIH; in fact, many studies show a lower observed rate of preeclampsia among smokers, although smoking clearly worsens other pregnancy outcomes such as fetal growth restriction and placental abruption. Thus, smoking is not associated with a significantly higher PIH incidence.