Abstract / Summary
Abstract Hyperemesis gravidarum has been associated with adverse offspring neurodevelopment, yet its effects on specific fetal brain structures remain poorly understood. This study assessed fetal limbic (fornix–hippocampus complex length and hippocampal thickness) and cortical (gyral–sulcal maturation and subarachnoid space width) development in moderate-to-severe hyperemesis gravidarum using targeted neurosonography. This prospective cross-sectional study included 33 women hospitalized for moderate-to-severe hyperemesis gravidarum in the first trimester and 44 frequency-matched healthy controls, followed prospectively to third-trimester assessment. Disease severity was graded at admission by the Pregnancy-Unique Quantification of Emesis score, and neurosonography was performed at 28–29 weeks. Hippocampal thickness and fornix–hippocampus length were predefined co-primary outcomes; subarachnoid space width, qualitative gyral–sulcal maturation, and estimated fetal weight were secondary. Severity markers were correlated with neurosonographic measurements within the hyperemesis gravidarum group. Hippocampal thickness was significantly lower in the hyperemesis gravidarum group and remained significant after adjustment for confounders (p < 0.001). Fornix–hippocampus length was shorter in the hyperemesis gravidarum group but not significant after adjustment (p = 0.105). Gyral–sulcal maturation was appropriate for gestational age, subarachnoid space width did not differ, and estimated fetal weight was comparable (p > 0.05). Within the hyperemesis gravidarum group, higher Pregnancy-Unique Quantification of Emesis scores, greater weight loss, and longer hospitalization were associated with reduced hippocampal thickness and shorter fornix–hippocampus length (p < 0.05). Moderate-to-severe hyperemesis gravidarum was associated with reduced fetal hippocampal thickness, whereas gyral–sulcal maturation, subarachnoid space width, and general fetal growth were comparable between groups, suggesting a possible structure-specific association involving the fetal limbic system.