borderline significanceP = 0.046
Malnutrition has a negative impact on fetal growth, including head circumference.[ 59 60 ] The reproductive process study of the Dutch famine in 1944–1945 showed that head circumference declined 2.7% during the famine, and rose 2.4% afterward.[ 61 ] Randomized controlled studies showed that adequate maternal and fetal nutrition improved prenatal head growth,[ 62 63 ] the difference still existed 7 weeks after birth (corrected value), but catch-up growth at 36 weeks narrowed the gap to borderline significance ( P = 0.046).[ 62 63 ] The economic condition may contribute to a false diagnosis of microcephaly, and postdiagnosis follow-up is necessary to make a definite diagnosis or complete correct diagnosis, considering the limitation of the operational definition in the size of head circumference.[ 64 ] While microcephaly is often identified after 20 weeks of gestation by ultrasonography, it's much earlier than the possible catch-up opportunity.