First-trimester Placental Volume Research Articles

Corpus luteum number and the maternal renin-angiotensin-aldosterone system as determinants of utero-placental (vascular) development: the Rotterdam Periconceptional Cohort

BackgroundPregnancies with > 1 corpus luteum (CL) display a hyperdynamic circulation and an increased risk of small-for-gestational age deliveries. Among the factors released by the CL is prorenin, the inactive precursor of renin. Since the renin-angiotensin-aldosterone system (RAAS) is involved in early hemodynamic pregnancy adaptation, we linked both CL number and first-trimester concentrations of prorenin (as an indicator of RAAS activity) and the aldosterone/renin ratio (as an indicator of angiotensin-independent aldosterone effectiveness) to non-invasive markers of utero-placental (vascular) development, measured longitudinally from the first trimester onwards.MethodsA total of 201 women, who conceived naturally or after in-vitro fertilization treatment (with 0 (n = 8), 1 (n = 143), or > 1 (n = 51) CL), were selected from the Rotterdam Periconceptional Cohort. Maternal RAAS components were determined at 11 weeks gestation. Placental volume and utero-placental vascular volume were measured from transvaginal 3D ultrasound scans at 7, 9 and 11 weeks gestation, pulsatility and resistance indices of the uterine arteries were assessed by pulsed wave Doppler ultrasounds at 7, 9, 11, 13, 22 and 32 weeks gestation. At birth placental weight was obtained using standardized procedures.ResultsPregnancies without a CL show lower uterine artery indices throughout gestation than 1 CL and > 1 CL pregnancies, while parameters of placental development are comparable among the CL groups. After adjustment for patient- and treatment-related factors, first-trimester prorenin concentrations are positively associated with uterine artery pulsatility and resistance indices (β 0.06, 95% CI 0.01;0.12, p = 0.04 and β 0.10, 95% CI 0.01;0.20, p = 0.04, respectively), while high prorenin concentrations are negatively associated with first-trimester utero-placental vascular volume (β -0.23, 95% CI -0.44;-0.02, p = 0.04) and placental weight (β -93.8, 95%CI -160.3;-27.4, p = 0.006). In contrast, the aldosterone/renin ratio is positively associated with first-trimester placental volume (β 0.12, 95% CI 0.01;0.24, p = 0.04).ConclusionsThe absence of a CL, resulting in low prorenin concentrations, associates with low uterine artery pulsatility and resistance, while high prorenin concentrations associate with a low utero-placental vascular volume and weight. These data support a scenario in which excess prorenin, by upregulating angiotensin II, increases uterine resistance, thereby preventing normal placental (vascular) development, and increasing the risk of small-for-gestational age deliveries. Simultaneously, high aldosterone concentrations, by ensuring volume expansion, exert the opposite.

Value of placental volume and vascular flow indices as predictors of intrauterine growth retardation

ObjectiveTo evaluate the utility of first-trimester placental volume and vascular flow indices to predict intrauterine growth retardation (IUGR). Study designIn 1004 singleton pregnancies attending routine care we recorded maternal characteristics, biophysical and biochemical factors included in the first trimester screening for aneuploidy (FTSA) and uterine artery pulsatility index (PI). Placental volume, Vascularization Index, Flow Index and Vascularization Flow Index were obtained. Customized curves were used to define IUGR. We compared pregnancies with and without IUGR. The performance of different predictive models was described by the areas under the receiver operator characteristic (AUROC) curve. Predictive models of IUGR were compared using a two by two approach and subset analysis was performed. ResultsPlacental volume and all vascular indices were significantly lower (p<0.001, p≤0.01), and uterine artery PI higher (p<0.001), in pregnancies with IUGR, with and without associated pre-eclampsia. Resultsobtained in the analysis of homogeneous subsets showed that the effectiveness of combined predictive models for IUGR improved significantly after adding vascular indices or placental volume to maternal characteristics, FTSA variables and uterine artery PI (AUROC curve value 0.703 (95% CI 0.663–0.744) versus 0.720 (95% CI 0.681–0.759) and 0.735 (95% CI 0.696–0.733), respectively). The most effective model at first trimester was that which included only maternal characteristics, uterine a-PI and placental volume, similar to that of the most complex model built with all the factors analyzed in this study AUROC curve value 0.735 (95% CI 0.696–0.773). ConclusionsPlacental volume and vascular indices were predictors factors of IUGR at first trimester. The effectiveness of combined predictive models for IUGR increased significantly after adding these factors, but the sensitivity of these models was too low for them to be considered useful in clinical practice.

Are There Differences in Placental Volume and Uterine Artery Doppler in Pregnancies Resulting From the Transfer of Fresh Versus Frozen-Thawed Embryos Through In Vitro Fertilization.

To compare uterine artery pulsatility index (PI) and 3-dimensional (3D) placental volume values in first-trimester pregnancies conceived naturally or through in vitro fertilization (IVF) technique using either fresh or cryopreserved embryo and to relate these measurements with preeclampsia (PE) development. Uterine artery PI and placental volume were measured at 11 + 0 to 13 + 6 weeks of gestation in 266 IVF pregnancies (139 women with fresh embryo and 127 women with frozen-thawed embryo transfer) and in 266 spontaneously conceived pregnancies matched for maternal age. Nulliparous women with singleton pregnancies were recruited. The mean, highest, and lowest uterine artery PI and placental volume values measured were converted to multiples of the expected normal median (MoM) adjusted for gestational age. The MoM values of IVF pregnancies were compared with those of the naturally conceived group and related to PE development. No differences were found in uterine artery PI MoM between the 3 groups. Placental volume was significantly lower than in both IVF groups when compared to the controls (fresh embryo IVF Z = 9.33; P ≤ .0001; frozen-thawed embryos IVF Z = 3.1; P = .04). The IVF pregnancies with fresh embryos showed placental volume MoM values significantly lower than in the frozen-thawed embryo IVF pregnancies (U = 5.4; P ≤ .0001). In fresh embryo IVF pregnancies developing PE placental volume values resulted lower than in the normotensive ones (U = 2.11; P = .03), while no differences were found for uterine artery PI values. First-trimester placental volume, as assessed by 3D ultrasound, is reduced in IVF pregnancies, and these differences are more marked in those obtained with fresh embryos than those obtained with cryopreservation. This may explain the better obstetrical and perinatal outcomes occurring with the former technique.

Analysis of measurement process of placental volume in early pregnancy: an interobserver reliability study

To examine concordance among results obtained in measurement process of first-trimester placental volume using 3D ultrasound and eXtended Imaging Virtual Organ Computed-aided AnaLysis (XI-VOCAL®, 3DXITM, Medison, Seoul, Korea) image analysis by three different operators. Twenty first-trimester normal pregnancy cases were selected for placental volume measuring using a Medison SA 8000 Live Prime® (Medison, Seoul, Korea) with a convex volumetric multifrequency abdominal probe. Images were processed and studied independently by three operators with different grade of training. Each operator obtained 50 slices per case. Thus, this study is based on 1000 measurements that have generated four different sets of placental volume determinations based on 5, 10, 15, and 20 slices, respectively. Results of measurement process were analyzed using reliability coefficients. There was a good degree of concordance in the placental length values obtained by all operators and not depend from the number of cuts measured [intraclass correlation coefficient (ICC)=0.734]. However, the number of cuts is important to obtain a placental volume with more accuracy. Reliability coefficients were low when determining placental volume adjusted to placental length (ICC=0.293), but combined results of the two operators that were trained in the same way showed higher coefficients of reliability (ICC=0.682), and therefore, greater concordance when comparing with the operator that was not trained in the same way. Higher coefficients of reliability guarantee high grades of concordance in the results among operators when measuring placental volumes independently, however, contouring process introduces high variability. Training in how to best use the image analysis software effectively assists in getting higher coefficients of reliability.

150: Association between first-trimester placental volume; birth weight and preeclampsia: a prospective study

150: Association between first-trimester placental volume; birth weight and preeclampsia: a prospective study

Association between first-trimester placental volume and birth weight

ObjectiveTo estimate the correlation between first-trimester placental volume, birth weight, small-for-gestational-age (SGA), and preeclampsia. MethodsA prospective study of women with singleton pregnancy at 11–13 weeks of gestation was conducted. First-trimester placental volume was measured using three-dimensional ultrasound and reported as multiple of median (MoM) for gestational age. Participants were followed until delivery where birth weight, placental weight, and occurrence of preeclampsia were collected. Non-parametric analyses were performed. ResultsWe reached a complete follow-up for 543 eligible women. First-trimester placental volume was significantly correlated with birth weight (correlation coefficient: 0.18; p < 0.0001) and placental weight (cc: 0.22; p < 0.0001) adjusted for gestational age. First-trimester placental volume was smaller in women who delivered SGA neonates (median MoM: 0.79; interquartile range: 0.62–1.00; p < 0.001) and greater in women who delivered large-for-gestational-age neonates (median MoM: 1.13; 0.95–1.49; p < 0.001) when compared to women with neonates between the 10th and 90th percentile (median MoM: 1.00; 0.81–1.25). First-trimester placental volume was not associated with the risk of preeclampsia (cc: 0.01; p = 0.87). ConclusionFirst-trimester placental volume is strongly associated with fetal and placental growth. However, we did not observe a correlation between placental volume and the risk of preeclampsia.

First-Trimester Placental Volume and Vascularization Measured by 3-Dimensional Power Doppler Sonography in Pregnancies With Low Serum Pregnancy-Associated Plasma Protein A Levels

The purpose of this study was to investigate the first-trimester placental volume and 3-dimensional (3D) power Doppler vascularization of pregnancies with low serum pregnancy-associated plasma protein A (PAPP-A) levels and to relate these findings to pregnancy outcomes. Three-dimensional power Doppler sonography of the placenta was performed at gestational ages of 11 weeks to 13 weeks 6 days in 84 pregnancies with PAPP-A concentrations of less than 0.4 multiple of the median (MoM). With a standardized setting, the placental volume and vascularization index (VI), flow index (FI), and vascularization-flow index (VFI) were calculated and related to pregnancy outcomes. Pregnancy outcomes were as follows: 57 pregnancies with birth weights at or above the 10th percentile (group A), 16 pregnancies with birth weights below the 10th percentile and normal Doppler findings in the umbilical artery throughout gestation (group B), and 11 pregnancies with birth weights below the 10th percentile and abnormal umbilical Doppler findings later in gestation (group C). No differences were found in PAPP-A levels among groups. Placental volume values were significantly lower than reference limits, but no differences were found between groups. In groups A and B, there were no significant differences in 3D Doppler indices. However, these indices were significantly lower in group C (VI mean difference, -1.904; P < .001; FI mean difference, -1.939; P < .001; VFI mean difference, -1.944; P < .001). Placental vascular indices were significantly related to the severity of intrauterine growth restriction (IUGR; VI, r = 0.438; P < .001; FI, r = 0.482; P < .001; VFI, r = 0.497; P < .001) but not to the PAPP-A MoM and placental volume values. Low serum maternal PAPP-A levels are associated with altered 3D placental Doppler indices, and these changes are related to subsequent development of IUGR and adverse pregnancy outcomes.

Implications cliniques de l'hCG dans les résultats de l'assistance médicale à la procréation au cours des cycles de transfert d'embryons frais et cryoconservés

Does mode of conception influence placental volume and other first-trimester outcomes?This retrospective single-centre case-control study led in Dijon University Hospital included 252 singleton pregnancies (84 IVF with either fresh embryo transfer or frozen-thawed embryo transfer [FET] and 168 natural conceptions). First-trimester placental volume, uterine artery pulsatility index and maternal serum PAPP-A and beta-HCG were measured. Statistical analyses were adjusted for gestational age, the newborn’s gender, maternal age, parity, body mass index and smoking status.Placental volume was significantly greater in the FET group than in the control group (P = 0.043) and fresh embryo transfer (P = 0.023) groups. At birth, fresh embryo transfer newborns were significantly smaller than controls (P = 0.01) and FET newborns (P = 0.008). Postpartum haemorrhage was far more frequent in FET than in controls and fresh embryo transfer group (38.1%, 2.6% and 1.9%, respectively; P < 0.0001). Placental volume positively correlated with PAPP-A, beta-HCG and the newborn’s birth weight, and negatively correlated with uterine artery pulsatility index.Placental volume and other first-trimester parameters are modified by IVF with fresh embryo transfer and FET compared with natural conception, but with opposite trends. Given the different protocols used for these techniques, hormonal treatment per se may have a major effect on pregnancy outcomes through the modification of placental invasiveness.

Placental volume, as measured by 3-dimensional sonography and levels of maternal plasma cell-free fetal DNA

Measurement of cell-free fetal (cff) DNA in maternal plasma may have clinical application in prenatal screening for fetal Down syndrome and preeclampsia. Little is known regarding the tissue of origin of these fetal-derived sequences. We tested the hypothesis that if the placenta is the major contributor of cff DNA, then an increased placental volume should be associated with higher maternal plasma cff DNA levels. We enrolled 143 pregnant women who underwent first-trimester placental volume measurement using 3-dimensional ultrasonography. Cff DNA in maternal plasma on the day of the scan was quantified by real-time polymerase chain reaction (PCR) amplification of a Y-chromosome sequence. The association between measured placental volume and maternal plasma cff DNA levels was analyzed along with relevant clinical variables. The median (25th, 75th percentiles) maternal plasma cff DNA level was 16.9 genome equivalents (GE)/mL (10.8, 28.7). Raw values were adjusted for gestational age and maternal body mass index. The median (25th, 75th percentiles) placental volume was 53.2 mL (43.0, 64.7), and median placental quotient (ratio of placental volume to fetal crown-rump length) was 1 mm2 (0.8, 1.1). Based on multivariate linear regression analyses, neither of the above placental measurements showed a significant association with maternal plasma cff DNA levels (P = .43 and .43, respectively). A modest association was found between plasma cff DNA levels and gravidity (P = .03). Our data did not show a significant association between either the placental volume or placental quotient, and maternal plasma cff DNA levels. We speculate that it is the extent of placental apoptosis that primarily affects the amount of cff DNA released into the maternal circulation.

First-trimester placental volume as a marker for chromosomal anomalies: preliminary results from an unselected population.

To compare first-trimester placental volume in chromosomally abnormal and normal pregnancies. Placental volumes were routinely recorded at the time of nuchal translucency thickness measurement at 10-13 weeks of gestation. This was done using customized three-dimensional ultrasound equipment and measurements were then converted to the placental quotient (placental volume/fetal crown-rump length). The possible difference in placental quotient between chromosomally normal and abnormal pregnancies was examined. A total of 2863 pregnancies was evaluated, including 17 with major chromosomal defects (nine cases of trisomy 21, four of trisomy 18, two of trisomy 13, and one each of Turner syndrome and 48,XXY + 21). The median placental quotient in the chromosomally abnormal group (0.67) was significantly lower than that in the normal fetuses (0.98). In nine of the 17 affected pregnancies the quotient was below the 10th centile of the normal range. Assessment of placental volume may prove to be useful in first-trimester risk assessment for chromosomal anomalies.