In Utero MRI Identifies Impaired Second Trimester Subplate Growth in Fetuses with Congenital Heart Disease.

The subplate is a transient brain structure which plays a key role in the maturation of the cerebral cortex. Altered brain growth and cortical development have been suggested in fetuses with complex congenital heart disease (CHD) in the third trimester. However, at an earlier gestation, the putative role of the subplate in altered brain development in CHD fetuses is poorly understood. This study aims to examine subplate growth (i.e., volume and thickness) and its relationship to cortical sulcal development in CHD fetuses compared with healthy fetuses by using 3D reconstructed fetal magnetic resonance imaging. We studied 260 fetuses, including 100 CHD fetuses (22.3-32 gestational weeks) and 160 healthy fetuses (19.6-31.9 gestational weeks). Compared with healthy fetuses, CHD fetuses had 1) decreased global and regional subplate volumes and 2) decreased subplate thickness in the right hemisphere overall, in frontal and temporal lobes, and insula. Compared with fetuses with two-ventricle CHD, those with single-ventricle CHD had reduced subplate volume and thickness in right occipital and temporal lobes. Finally, impaired subplate growth was associated with disturbances in cortical sulcal development in CHD fetuses. These findings suggested a potential mechanistic pathway and early biomarker for the third-trimester failure of brain development in fetuses with complex CHD. SIGNIFICANCE STATEMENT: Our findings provide an early biomarker for brain maturational failure in fetuses with congenital heart disease, which may guide the development of future prenatal interventions aimed at reducing neurological compromise of prenatal origin in this high-risk population.

Maternal mental distress and cortisol levels in pregnancies with congenital heart disease.

OBJECTIVES: Prenatal maternal stress is associated with adverse offspring outcomes, which may be mediated by maternal stress hormones. However, evidence supporting the association between maternal stress and cortisol levels in high-risk pregnancies is limited. This study aims to determine the relationship between self-reported maternal mental distress and maternal salivary cortisol levels in pregnancies complicated by foetal CHD compared with healthy pregnancies. METHODS: We recruited women with pregnancies complicated by foetal CHD and healthy pregnancies. Maternal saliva was collected between 22 and 40 gestational weeks. Standardized questionnaires measuring stress, depression, and anxiety were completed by patients. Generalized estimating equation was used to evaluate associations between maternal mental distress scales and cortisol levels. RESULTS: We studied 165 women (55 CHD, 110 controls) and collected 504 cortisol samples (160 CHD, 344 controls). Women carrying CHD foetuses had higher stress, anxiety, and depression scores compared to women carrying healthy foetuses. However, maternal cortisol levels did not significantly differ in CHD and controls. Cortisol levels were higher in women carrying foetuses with functionally single-ventricle versus two-ventricle CHD. In both CHD and controls, there was no significant association between maternal stress, depression or anxiety scores and cortisol levels. CONCLUSION: Our data suggest that self-reported maternal stress, anxiety, and depression are not associated with maternal salivary cortisol levels in CHD and healthy pregnancies. The impact of maternal mental distress on foetal health may be through other mediating pathways other than maternal cortisol concentrations.

Non-invasive measurement of biochemical profiles in the healthy fetal brain.

Proton magnetic resonance spectroscopy (1H-MRS) of the fetal brain can be used to study emerging metabolite profiles in the developing brain. Identifying early deviations in brain metabolic profiles in high-risk fetuses may offer important adjunct clinical information to improve surveillance and management during pregnancy. OBJECTIVE: To investigate the normative trajectory of the fetal brain metabolites during the second half of gestation, and to determine the impact of using different Cramer-Rao Lower Bounds (CRLB) threshold on metabolite measurements using magnetic resonance spectroscopy. STUDY DESIGN: We prospectively enrolled 219 pregnant women with normal fetal ultrasound and biometric measures. We performed a total of 331 fetal 1H-MRS studies with gestational age in the rage of 18-39 weeks with 112 of the enrolled participants scanned twice. All the spectra in this study were acquired on a GE 1.5 T scanner using long echo-time of 144 â€‹ms and analyzed in LCModel. RESULTS: We successfully acquired and analyzed fetal 1H-MRS with a success rate of 93%. We observed increases in total NAA, total creatine, total choline, scyllo inositol and total NAA-to-total choline ratio with advancing GA. Our results also showed faster increases in total NAA and total NAA-to-total choline ratio during the third trimester compared to the second trimester. We also observed faster increases in total choline and total NAA in female fetuses. Increasing the Cramer-Rao lower bounds threshold progressively from 100% to 40%-20% increased the mean metabolite concentrations and decreased the number of observations available for analysis. CONCLUSION: We report serial fetal brain biochemical profiles in a large cohort of health fetuses studied twice in gestation with a high success rate in the second and third trimester of pregnancy. We present normative in-vivo fetal brain metabolite trajectories over a 21-week gestational period which can be used to non-invasively measure and monitor brain biochemistry in the healthy and high-risk fetus.

Association of Elevated Maternal Psychological Distress, Altered Fetal Brain, and Offspring Cognitive and Social-Emotional Outcomes at 18 Months.

Importance: Prenatal maternal psychological distress is associated with disturbances in fetal brain development. However, the association between altered fetal brain development, prenatal maternal psychological distress, and long-term neurodevelopmental outcomes is unknown. Objective: To determine the association of fetal brain development using 3-dimensional magnetic resonance imaging (MRI) volumes, cortical folding, and metabolites in the setting of maternal psychological distress with infant 18-month neurodevelopment. Design, Setting, and Participants: Healthy mother-infant dyads were prospectively recruited into a longitudinal observational cohort study from January 2016 to October 2020 at Children's National Hospital in Washington, DC. Data analysis was performed from January 2016 to July 2021. Exposures: Prenatal maternal stress, anxiety, and depression. Main Outcomes and Measures: Prenatal maternal stress, anxiety, and depression were measured using validated self-report questionnaires. Fetal brain volumes and cortical folding were measured from 3-dimensional, reconstructed T2-weighted MRI scans. Fetal brain creatine and choline were quantified using proton magnetic resonance spectroscopy. Infant neurodevelopment at 18 months was measured using Bayley Scales of Infant and Toddler Development III and Infant-Toddler Social and Emotional Assessment. The parenting stress in the parent-child dyad was measured using the Parenting Stress Index-Short Form at 18-month testing. Results: The cohort consisted of 97 mother-infant dyads (mean [SD] maternal age, 34.79 [5.64] years) who underwent 184 fetal MRI visits (87 participants with 2 fetal studies each) with maternal psychological distress measures between 24 and 40 gestational weeks and completed follow-up infant neurodevelopmental testing. Prenatal maternal stress was negatively associated with infant cognitive performance (ß = -0.51; 95% CI, -0.92 to -0.09; P = .01), and this association was mediated by fetal left hippocampal volume. In addition, prenatal maternal anxiety, stress, and depression were positively associated with all parenting stress measures at 18-month testing. Finally, fetal cortical local gyrification index and sulcal depth were negatively associated with infant social-emotional performance (local gyrification index: ß = -54.62; 95% CI, -85.05 to -24.19; P < .001; sulcal depth: ß = -14.22; 95% CI, -23.59 to -4.85; P = .002) and competence scores (local gyrification index: ß = -24.01; 95% CI, -40.34 to -7.69; P = .003; sulcal depth: ß = -7.53; 95% CI, -11.73 to -3.32; P < .001). Conclusions and Relevance: In this cohort study of 97 mother-infant dyads, fetal cortical local gyrification index and sulcal depth were associated with infant 18-month social-emotional and competence outcomes, and fetal left hippocampal volume mediated the association between prenatal maternal stress and infant cognitive outcome. These findings suggest that altered prenatal brain development in the setting of elevated maternal distress has adverse infant sociocognitive outcomes, and identifying early biomarkers associated with long-term neurodevelopment may assist in early targeted interventions.