Midline structures and cortical development in late-onset fetal growth restriction according to Doppler status: prospective study.

OBJECTIVES: Fetuses with late-onset growth restriction (FGR) have a higher risk of suboptimal neurocognitive performance after birth. Previous studies have reported that impaired brain and cortical development can start in utero. The primary aim of this study was to report midline structure growth and cortical development in fetuses with late-onset FGR according to its severity; the secondary aim was to elucidate whether the severity of FGR, as defined by the presence of abnormal Doppler findings, plays a role in affecting brain growth and maturation. METHODS: This was a prospective observational study that included fetuses with late-onset FGR (defined according to the Delphi FGR criteria) undergoing neurosonography between 32 and 34 weeks' gestation. Midline structure (corpus callosum (CC) and cerebellar vermis (CV)) length and cortical development, including the depth of the Sylvian (SF), parieto-occipital (POF) and calcarine (CF) fissures, were compared between late-onset FGR, small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) fetuses. Subgroup analysis according to the severity of FGR (normal vs abnormal fetal Doppler) was also performed. Univariate analysis was used to analyze the data. RESULTS: A total of 52 late-onset FGR fetuses with normal Doppler findings, 60 late-onset FGR fetuses with abnormal Doppler findings, 64 SGA fetuses and 100 AGA fetuses were included in the analysis. When comparing AGA controls with SGA fetuses, late-onset FGR fetuses with normal Doppler findings and late-onset FGR fetuses with abnormal Doppler findings, there was a progressive and significant reduction in the absolute values of the following parameters: CC length (median (interquartile range (IQR)), 43.5 (28.9-56.1) mm vs 41.9 (27.8-51.8) mm vs 38.5 (29.1-50.5) mm vs 31.7 (23.8-40.2) mm; K = 26.68; P < 0.0001), SF depth (median (IQR), 14.5 (10.7-16.8) mm vs 12.7 (9.8-15.1) mm vs 11.9 (9.1-13.4) mm vs 8.3 (6.7-10.3) mm; K = 75.82; P < 0.0001), POF depth (median (IQR), 8.6 (6.3-11.1) mm vs 8.1 (5.6-10.4) mm vs 7.8 (6.1-9.3) mm vs 6.6 (4.2-8.0) mm; K = 45.06; P < 0.0001) and CF depth (median (IQR), 9.3 (6.7-11.5) mm vs 8.2 (5.7-10.7) mm vs 7.7 (5.2-9.4) mm vs 6.3 (4.5-7.2) mm; K = 46.14; P < 0.0001). Absolute CV length was significantly higher in AGA fetuses compared with all other groups, although the same progressive pattern was not noted (median (IQR), 24.9 (17.6-29.2) mm vs 21.6 (15.2-26.1) mm vs 19.1 (13.8-25.9) mm vs 21.0 (13.5-25.8) mm; K = 16.72; P = 0.0008). When the neurosonographic variables were corrected for fetal head circumference, a significant difference in the CC length and SF, POF and CF depths, but not CV length, was observed only in late-onset FGR fetuses with abnormal Doppler findings when compared with AGA and SGA fetuses. CONCLUSIONS: Fetuses with late-onset FGR had shorter CC length and delayed cortical development when compared with AGA fetuses. After controlling for fetal head circumference, these differences remained significant only in late-onset FGR fetuses with abnormal Doppler. These findings support the existence of a link between brain development and impaired placental function. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Placental volume and uterine artery Doppler evaluation at 11 + 0 to 13 + 6 weeks' gestation in pregnancies conceived with in-vitro fertilization: comparison between autologous and donor oocyte recipients.

OBJECTIVE: To compare first-trimester uterine artery pulsatility index (UtA-PI) and three-dimensional (3D) placental volume in pregnancies conceived through in-vitro fertilization (IVF) using autologous or donor oocytes and pregnancies conceived naturally, and to relate these measurements to the development of pre-eclampsia (PE). METHODS: UtA-PI and placental volume were measured at 11 + 0 to 13 + 6 weeks of gestation in 416 IVF pregnancies (307 with autologous and 109 with donor oocytes) and in 498 spontaneously conceived pregnancies. We recruited nulliparous women with singleton pregnancy. The measured mean UtA-PI and placental volume values were converted to multiples of the expected normal median (MoM), adjusted for gestational age. MoM values of IVF pregnancies were compared with MoM values of the naturally conceived pregnancies and related to PE development. RESULTS: Placental volume was significantly reduced in IVF pregnancies (K = 169.3; P < 0.0001) compared with natural pregnancies. No difference was found in UtA-PI MoM between the two groups. Among IVF pregnancies, significantly lower placental volumes were seen in those that received donor oocytes when compared with those with autologous oocytes (z = 3.89; P < 0.001). In IVF pregnancies that developed PE, lower values of placental volume were demonstrated with respect to normotensive pregnancies (donor: U = 6.8; P = 0.009; autologous: U = 5.1; P = 0.023), whereas no difference was found in UtA-PI. Multivariate logistic regression analysis demonstrated that placental volume (odds ratio (OR), 1.97 (95% CI, 1.33-2.27)) and donor oocytes in IVF pregnancy (OR, 2.24 (95% CI, 1.5-2.83)) were independent predictors of PE, whereas autologous oocytes in IVF pregnancy were not found to be significant in the model. CONCLUSIONS: First-trimester placental volume, as assessed by 3D ultrasound, is reduced in IVF pregnancies and this reduction is more marked in those involving donor oocyte recipients. The relative decrease in placental volume in IVF pregnancies that developed PE suggests an etiological mechanism different from uterine perfusion in such patients. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Uterine artery Doppler evaluation in twin pregnancies at 11 + 0 to 13 + 6 weeks of gestation.

OBJECTIVES: To compare uterine artery pulsatility index (PI) obtained at 11 + 0 to 13 + 6 weeks of gestation in singleton and twin pregnancies and to evaluate changes in PI values of twin pregnancies developing pre-eclampsia (PE) or small-for-gestational age (SGA) of either one or both fetuses. METHODS: Uterine artery PI was measured in 421 twin pregnancies (384 dichorionic and 37 monochorionic) and in 500 singleton pregnancies. The measured mean and lowest uterine artery PI values were converted to multiples of the expected normal median (MoM) after correction for maternal body mass index, ethnicity and gestational age. The median PI-MoM values of twins were compared with those of singleton pregnancies. In twin pregnancies, PI-MoM values were analyzed according to chorionicity, development of early-onset (< 34 weeks) or late-onset (≥ 34 weeks) PE and SGA of one or both twins. RESULTS: Uterine artery PI-MoM was significantly lower in twin compared with singleton pregnancies (mean K = 174.31, P < 0.0001, lowest K = 139.27, P < 0.0001). However, there were no significant differences in the uterine artery PI-MoM values between monochorionic and dichorionic twins. The uterine artery PI in twin pregnancies that developed early-onset PE (P < 0.001) and SGA of both twins (P < 0.05) was higher than the uterine artery PI in uncomplicated twin pregnancies, whereas no differences were found for late PE or SGA of one twin. CONCLUSIONS: First-trimester placental impedance to flow, as assessed by uterine artery Doppler examination, is reduced in twin pregnancies, with no differences related to chorionicity. The relative increase of uterine artery PI found in twin pregnancies that developed early PE and SGA of both twins suggests that first-trimester uterine artery assessment may be useful in identifying such complications.

An algorithm based on OmniView technology to reconstruct sagittal and coronal planes of the fetal brain from volume datasets acquired by three-dimensional ultrasound.

OBJECTIVE: To describe a novel algorithm, based on the new display technology 'OmniView', developed to visualize diagnostic sagittal and coronal planes of the fetal brain from volumes obtained by three-dimensional (3D) ultrasonography. METHODS: We developed an algorithm to image standard neurosonographic planes by drawing dissecting lines through the axial transventricular view of 3D volume datasets acquired transabdominally. The algorithm was tested on 106 normal fetuses at 18-24 weeks of gestation and the visualization rates of brain diagnostic planes were evaluated by two independent reviewers. The algorithm was also applied to nine cases with proven brain defects. RESULTS: The two reviewers, using the algorithm on normal fetuses, found satisfactory images with visualization rates ranging between 71.7% and 96.2% for sagittal planes and between 76.4% and 90.6% for coronal planes. The agreement rate between the two reviewers, as expressed by Cohen's kappa coefficient, was > 0.93 for sagittal planes and > 0.89 for coronal planes. All nine abnormal volumes were identified by a single observer from among a series including normal brains, and eight of these nine cases were diagnosed correctly. CONCLUSIONS: This novel algorithm can be used to visualize standard sagittal and coronal planes in the fetal brain. This approach may simplify the examination of the fetal brain and reduce dependency of success on operator skill.

First-trimester umbilical vein blood flow in pregnancies with low serum pregnancy-associated plasma protein-A levels: an early predictor of fetal growth restriction.

OBJECTIVE: To investigate umbilical vein blood flow (UVBF) during the first trimester in pregnancies with low serum pregnancy-associated plasma protein-A (PAPP-A) levels and to relate umbilical vein (UV) diameter, time-averaged maximum velocity (TAMXV) and UVBF values to the subsequent development of fetal intrauterine growth restriction (IUGR). METHODS: UVBF assessment was performed at 11 + 0 to 13 + 6 weeks' gestation in 102 singleton pregnancies with PAPP-A concentrations of < 0.3 multiples of the median. UV diameter, UV-TAMXV and UVBF were calculated and analyzed in relation to pregnancy outcome. RESULTS: Pregnancy outcomes were: 51 pregnancies with birth weight ≥ 10(th) centile (Group A), 30 pregnancies with birth weight < 10(th) centile with normal Doppler in the umbilical artery throughout gestation (Group B) and 21 pregnancies with birth weight < 10(th) centile and abnormal umbilical artery Doppler later in gestation (Group C). No differences were found in PAPP-A levels between groups. Group C fetuses exhibited significantly lower values of UV-TAMXV (z-score - 1.99 SDs, t = 8.527, P ≤ 0.0001) and UVBF (z-score - 0.97 SDs, t = 7.420, P ≤ 0.0001) in comparison with normal reference ranges, while no differences were found in Groups A or B. CONCLUSIONS: Decreased UV-TAMXV and UVBF at 11 + 0 to 13 + 6 weeks' gestation identify fetuses at risk of developing IUGR among pregnancies with low levels of PAPP-A.