Which maternal factor is most likely associated with asymmetric intrauterine growth restriction?

Which maternal factor is most likely associated with asymmetric intrauterine growth restriction?

• A. Heavy maternal smoking throughout pregnancy
• B. Gestational diabetes
• C. Maternal obesity
• D. Hypertension

Answer: (A)

Asymmetric intrauterine growth restriction reflects reduced placental blood flow late in pregnancy, so the fetus becomes small overall but with a relatively normal head size—the brain-sparing effect. Heavy smoking throughout pregnancy is a classic driver of this pattern because nicotine and other smoke-related substances cause chronic uteroplacental vasoconstriction and placental dysfunction, leading to chronic fetal hypoxia and restricted growth, especially in the abdomen. Gestational diabetes tends to produce larger babies rather than growth restriction. Maternal obesity is more commonly linked to increased fetal size and metabolic risks. Hypertension can also impair placental perfusion and contribute to growth issues, but smoking is the strongest and most consistent association with the asymmetric pattern seen in late-petal placental insufficiency.

Asymmetric intrauterine growth restriction reflects reduced placental blood flow late in pregnancy, so the fetus becomes small overall but with a relatively normal head size—the brain-sparing effect. Heavy smoking throughout pregnancy is a classic driver of this pattern because nicotine and other smoke-related substances cause chronic uteroplacental vasoconstriction and placental dysfunction, leading to chronic fetal hypoxia and restricted growth, especially in the abdomen.

Gestational diabetes tends to produce larger babies rather than growth restriction. Maternal obesity is more commonly linked to increased fetal size and metabolic risks. Hypertension can also impair placental perfusion and contribute to growth issues, but smoking is the strongest and most consistent association with the asymmetric pattern seen in late-petal placental insufficiency.