First-trimester utero-placental (vascular) development and embryonic and fetal growth: The Rotterdam periconception cohort

Morphologic development of the first-trimester utero-placental vasculature is positively associated with embryonic and fetal growth: the Rotterdam Periconception Cohort

STUDY QUESTION

Is morphologic development of the first-trimester utero-placental vasculature associated with embryonic growth and development, fetal growth, and birth weight percentiles?

SUMMARY ANSWER

Using the utero-placental vascular skeleton (uPVS) as a new imaging marker, this study reveals morphologic development of the first-trimester utero-placental vasculature is positively associated with embryonic growth and development, fetal growth, and birth weight percentiles.

WHAT IS KNOWN ALREADY

First-trimester development of the utero-placental vasculature is associated with placental function, which subsequently impacts embryonic and fetal ability to reach their full growth potential. The attribution of morphologic variations in the utero-placental vascular development, including the vascular structure and branching density, on prenatal growth remains unknown.

STUDY DESIGN, SIZE, DURATION

This study was conducted in the VIRTUAL Placental study, a subcohort of 214 ongoing pregnancies, embedded in the prospective observational Rotterdam Periconception Cohort (Predict study). Women were included before 10 weeks gestational age (GA) at a tertiary referral hospital in The Netherlands between January 2017 and March 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We obtained three-dimensional power Doppler volumes of the gestational sac including the embryo and the placenta at 7, 9, and 11 weeks of gestation. Virtual Reality-based segmentation and a recently developed skeletonization algorithm were applied to the power Doppler volumes to generate the uPVS and to measure utero-placental vascular volume (uPVV). Absolute vascular morphology was quantified by assigning a morphologic characteristic to each voxel in the uPVS (i.e. end-, bifurcation-crossing-, or vessel point). Additionally, total vascular length (mm) was calculated. The ratios of the uPVS characteristics to the uPVV were calculated to determine the density of vascular branching. Embryonic growth was estimated by crown-rump length and embryonic volume. Embryonic development was estimated by Carnegie stages. Fetal growth was measured by estimated fetal weight in the second and third trimester and birth weight percentiles. Linear mixed models were used to estimate trajectories of longitudinal measurements. Linear regression analysis with adjustments for confounders was used to evaluate associations between trajectories of the uPVS and prenatal growth. Groups were stratified for conception method (natural/IVF-ICSI conceptions), fetal sex (male/female), and the occurrence of placenta-related complications (yes/no).

MAIN RESULTS AND THE ROLE OF CHANCE

Increased absolute vascular morphologic development, estimated by positive random intercepts of the uPVS characteristics, is associated with increased embryonic growth, reflected by crown-rump length (endpoints β = 0.017, 95% CI [0.009; 0.025], bifurcation points β = 0.012, 95% CI [0.006; 0.018], crossing points β = 0.017, 95% CI [0.008; 0.025], vessel points β = 0.01, 95% CI [0.002; 0.008], and total vascular length β = 0.007, 95% CI [0.003; 0.010], and similarly with embryonic volume and Carnegie stage, all P-values ≤ 0.01. Density of vascular branching was negatively associated with estimated fetal weight in the third trimester (endpoints: uPVV β = -94.972, 95% CI [-185.245; -3.698], bifurcation points: uPVV β = -192.601 95% CI [-360.532; -24.670]) and birth weight percentiles (endpoints: uPVV β = -20.727, 95% CI [-32.771; -8.683], bifurcation points: uPVV β -51.097 95% CI [-72.257; -29.937], and crossing points: uPVV β = -48.604 95% CI [-74.246; -22.961])), all P-values < 0.05. After stratification, the associations were observed in natural conceptions specifically.

LIMITATION, REASONS FOR CAUTION

Although the results of this prospective observational study clearly demonstrate associations between first-trimester utero-placental vascular morphologic development and prenatal growth, further research is required before we can draw firm conclusions about a causal relationship.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings support the hypothesis that morphologic variations in utero-placental vascular development play a role in the vascular mechanisms involved in embryonic and fetal growth and development. Application of the uPVS could benefit our understanding of the pathophysiology underlying placenta-related complications. Future research should focus on the clinical applicability of the uPVS as an imaging marker for the early detection of fetal growth restriction.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Department of Obstetrics and Gynecology of the Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. There are no conflicts of interest.

TRIAL REGISTRATION NUMBER

Registered at the Dutch Trial Register (NTR6854).

Paternal age and first trimester placental size and growth: The Rotterdam Periconceptional Cohort

INTRODUCTION

Despite a noticeable trend of delayed fatherhood, less is known about the impact of paternal age on the paternally programmed placenta. We hypothesize that paternal aging affects seminal quality and as such induces ageing-related epigenetic alterations that influence placental growth. Our main aim is to investigate associations between paternal age and first trimester (vascular) placental growth trajectories.

METHODS

Pregnant women were enrolled before 10 weeks of gestation in the Rotterdam Periconceptional Cohort (Predict study). Placental volumes (PV) and utero-placental vascular volumes (uPVV) were measured at 7, 9, and 11 weeks gestation. Associations between paternal age and PV and uPVV were investigated using linear mixed models and the maximum likelihood ratio test to test non-linear relationships. We adjusted for gestational age, fetal sex, parental smoking and maternal age, BMI, education and parity, and stratified for conception mode.

RESULTS

From 808 pregnancies we obtained 1313 PV and from 183 pregnancies 345 uPVV measurements. We show no associations between paternal age and PV (p = 0.934) and uPVV (p = 0.489) in our total population or in pregnancies conceived naturally (PV p = 0.166; uPVV p = 0.446) and after IVF/ICSI (PV p = 0.909; uPVV p = 0.749). For example, PV was 0.9% smaller (95% CI -5.7%-7.1%) in fathers aged 40 compared to 30 years old at 9 weeks gestation in the total study population.

DISCUSSION

We are not demonstrating a significant impact of paternal age on first trimester placental growth in a tertiary care population. Given the trend of increasing paternal age, our study should be repeated in the general population.

First-trimester 3D power Doppler imaging markers of utero-placental vascular development are associated with placental weight and diameter at birth: The Rotterdam Periconception Cohort

INTRODUCTION

Early utero-placental vascular development impacts placental development and function throughout pregnancy. We investigated whether impaired first-trimester utero-placental vascular development is associated with pathologic features of the postpartum placenta.

METHODS

In this prospective observational study of 65 ongoing pregnancies, we obtained three-dimensional power Doppler ultrasounds of the placenta at 7, 9 and 11 weeks of gestation. We applied VOCAL software to measure placental volume (PV), virtual reality based segmentation to measure utero-placental vascular volume (uPVV) and applied a skeletonization algorithm to generate the utero-placental vascular skeleton (uPVS). Vascular morphology was quantified by assigning a morphologic characteristic to each voxel in the uPVS (i.e. end-, bifurcation-, crossing- or vessel point). Following delivery, placentas were measured and histologically examined according to the Amsterdam criteria to assess maternal vascular malperfusion (MVM). We used linear mixed models to estimate trajectories of PV, uPVV and uPVS development. Multivariable linear regression analysis with adjustments for confounders was used to evaluate associations between PV, uPVV and uPVS development and features of the postpartum placenta.

RESULTS

We observed no associations between first-trimester PV development and measurements of the postpartum placenta. Increased first-trimester utero-placental vascular development, reflected by uPVV (β = 0.25 [0.01; 0.48]), uPVS end points (β = 0.25 [0.01; 0.48]), bifurcation points (β = 0.22 [0.05; 0.37]), crossing points (β = 0.29 [0.07; 0.52]) and vessel points (β = 0.09 [0.02; 0.17]) was positively associated with the postpartum placental diameter. uPVV was positively associated with postpartum placental weight. No associations were found with MVM.

DISCUSSION

Development of the first-trimester utero-placental vasculature is associated with postpartum placental size, whereas placental tissue development contributes to a lesser extent.

Glutathione-Responsive Methotrexate Polymersomes for Potential Management of Ectopic Pregnancy

The first-line treatment for ectopic pregnancy (EP), the chemotherapeutic methotrexate (MTX), has a failure rate of more than 10%, which can lead to severe complications or death. Inadequate accumulation of administered MTX at the ectopic implantation site significantly contributes to therapeutic failure. This study reports the first glutathione-responsive polymersomes for efficient delivery of MTX to the implantation site and its triggered release in placental cells. Fluorescence and photoacoustic imaging have confirmed that the developed polymersomes preferentially accumulate after systemic administration in the implantation site of pregnant mice at early gestational stages. The high concentrations of intracellular glutathione (GSH) reduce an incorporated disulfide bond within polymersomes upon internalization into placental cells, resulting in their disintegration and efficient drug release. Consequently, MTX delivered by polymersomes induces pregnancy demise in mice, as opposed to free MTX at the same dose regimen. To achieve the same therapeutic efficacy with free MTX, a sixfold increase in dosage is required. In addition, mice successfully conceive and birth healthy pups following a prior complete pregnancy demise induced by methotrexate polymersomes. Therefore, the developed MTX nanomedicine can potentially improve EP management and reduce associated mortality rates and related cost.

Assessment of first-trimester utero-placental vascular morphology by 3D power Doppler ultrasound image analysis using a skeletonization algorithm: the Rotterdam Periconception Cohort

STUDY QUESTION

Can three-dimensional (3D) Power Doppler (PD) ultrasound and a skeletonization algorithm be used to assess first-trimester development of the utero-placental vascular morphology?

SUMMARY ANSWER

The application of 3D PD ultrasonography and a skeletonization algorithm facilitates morphologic assessment of utero-placental vascular development in the first trimester and reveals less advanced vascular morphologic development in pregnancies with placenta-related complications than in pregnancies without placenta-related complications.

WHAT IS KNOWN ALREADY

Suboptimal development of the utero-placental vasculature is one of the main contributors to the periconceptional origin of placenta-related complications. The nature and attribution of aberrant vascular structure and branching patterns remain unclear, as validated markers monitoring first-trimester utero-placental vascular morphologic development are lacking.

STUDY DESIGN, SIZE, DURATION

In this prospective observational cohort, 214 ongoing pregnancies were included before 10 weeks gestational age (GA) at a tertiary hospital between January 2017 and July 2018, as a subcohort of the ongoing Rotterdam Periconception Cohort study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

By combining 3D PD ultrasonography and virtual reality, utero-placental vascular volume (uPVV) measurements were obtained at 7, 9 and 11 weeks GA. A skeletonization algorithm was applied to the uPVV measurements to generate the utero-placental vascular skeleton (uPVS), a network-like structure containing morphologic characteristics of the vasculature. Quantification of vascular morphology was performed by assigning a morphologic characteristic to each voxel in the uPVS (end-, vessel-, bifurcation- or crossing-point) and calculating total vascular network length. A Mann–Whitney U test was performed to investigate differences in morphologic development of the first-trimester utero-placental vasculature between pregnancies with and without placenta-related complications. Linear mixed models were used to estimate trajectories of the morphologic characteristics in the first trimester.

MAIN RESULTS AND THE ROLE OF CHANCE

All morphologic characteristics of the utero-placental vasculature increased significantly in the first trimester (P < 0.005). In pregnancies with placenta-related complications (n = 54), utero-placental vascular branching was significantly less advanced at 9 weeks GA (vessel points P = 0.040, bifurcation points P = 0.050, crossing points P = 0.020, total network length P = 0.023). Morphologic growth trajectories remained similar after adjustment for parity, conception mode, foetal sex and occurrence of placenta-related complications.

LIMITATIONS, REASONS FOR CAUTION

The tertiary setting of this prospective observational study provides high internal, but possibly limited external, validity. Extrapolation of the study’s findings should therefore be addressed with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The uPVS enables assessment of morphologic development of the first-trimester utero-placental vasculature. Further investigation of this innovative methodology needs to determine its added value for the assessment of (patho-) physiological utero-placental vascular development.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Department of Obstetrics and Gynecology of the Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. There are no conflicts of interest.

TRIAL REGISTRATION NUMBER

Registered at the Dutch Trial Register (NTR6854).

Clinical value of serum VEGF and sFlt-1 in pernicious placenta previa

This study was designed to explore the expression and the diagnostic value of vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) in pernicious placenta previa (PPP) combined placental accreta/increta. A total of 140 PPP patients were enrolled and divided into two groups: 56 patients with placenta accreta/increta (PA group), and 84 patients without placenta accreta/increta (non-PA group). In the same period, 46 pregnant women without PPP who had undergone caesarean section were selected as controls. The levels of VEGF and sFlt-1 in serum were detected by enzyme-linked immunosorbent assay. Diagnostic efficiency of VEGF and sFlt-1 in serum were evaluated by receiver operating characteristics curve. It was found that both VEGF and sFlt-1 had diagnostic value for PPP and placenta accreta/increta combined PPP. In addition, the levels of VEGF and sFlt-1 could be used to distinguish placenta accreta from placenta increta. VEGF was negatively correlated with sFlt-1 in PPP patients. In summary, the levels of VEGF and sFlt-1 could be used as auxiliary indicators to diagnose PPP and distinguish between placenta accreta and increta.KEY POINTSThe levels of VEGF and sFlt-1 could be used to distinguish placenta accreta from placenta increta.VEGF is negatively correlated with sFlt-1 in PPP patients.The levels of VEGF and sFlt-1 could be used as auxiliary indicators to diagnose PPP and distinguish between placenta accreta and increta.

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

BACKGROUND

Pregnancies 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.

METHODS

A 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.

RESULTS

Pregnancies 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).

CONCLUSIONS

The 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.

First-trimester maternal haemodynamic adaptation to pregnancy and placental, embryonic and fetal development: the prospective observational Rotterdam Periconception cohort

Objective

To investigate whether first‐trimester maternal haemodynamic adaptation impacts placental, embryonic and fetal development as well as birth outcomes in pregnancies with and without placenta‐related complications.

Design

Prospective observational cohort.

Setting

A Dutch tertiary hospital.

Population

Two hundred and fourteen ongoing pregnancies.

Methods

At 7, 9 and 11 weeks of gestation, we assessed maternal haemodynamic adaptation (mean arterial blood pressure [MAP], uterine artery [UtA] blood flow) and placental development (placental volume [PV], uteroplacental vascular volume [uPVV]) using three‐dimensional power Doppler ultrasound volumes, and embryonic development (crown–rump length, embryonic volume). At 22 and 32 weeks of gestation, fetal development was assessed by estimated fetal weight. Birth outcomes (birthweight, placental weight) were extracted from medical records. Linear mixed modelling and linear regression analyses were applied.

Main outcome measures

Birthweight centile and placental weight.

Results

In placenta‐related complications (n= 55, 25.7%), reduced haemodynamic adaptation, i.e. higher UtA pulsatility index (PI) and resistance index (RI) trajectories, was associated with smaller increase in PV (β = −0.559, 95% CI −0.841 to −0.278, P< 0.001; β = −0.579, 95% CI −0.878 to −0.280, P< 0.001) and uPVV trajectories (UtA PI: β = −0.301, 95% CI −0.578 to −0.023, P= 0.034). At birth, reduced haemodynamic adaptation was associated with lower placental weight (UtA PI: β = −0.502, 95% CI −0.922 to −0.082, P= 0.022; UtA RI: β = −0.435, 95% CI −0.839 to −0.032, P= 0.036). In pregnancies without placenta‐related complications, higher MAP trajectories were positively associated with birthweight centile (β = 0.398, 95% CI 0.049–0.748, P= 0.025).

Conclusions

Reduced first‐trimester maternal haemodynamic adaptation impacts both placental size and vascularisation and birthweight centile, in particular in pregnancies with placenta‐related complications.

Tweetable abstract

Reduced first‐trimester maternal haemodynamic adaptation to pregnancy impairs early placental development.

Periconceptional maternal and paternal homocysteine levels and early utero-placental (vascular) growth trajectories: The Rotterdam periconception cohort

INTRODUCTION

Maternal elevated plasma total homocysteine (tHcy) is involved in the origin of several placenta-related pregnancy complications. The first trimester is the most sensitive period for placentation influenced by maternal and paternal health. The aim is to study associations between periconceptional parental tHcy levels and utero-placental growth trajectories in the first trimester of pregnancy.

METHODS

Pregnant women and their partners were enrolled before 10 weeks of gestation in the Virtual Placenta study as subcohort of the Rotterdam periconception cohort (Predict study). A total of 190 women with a singleton pregnancy, of which 109 conceived naturally and 81 after IVF/ICSI treatment, were included. We measured serial utero-placental vascular volumes (uPVV) and placental volumes (PV) at 7, 9 and 11 weeks of gestation. First-trimester trajectories of PV were also measured in 662 pregnancies from the total Predict study.

RESULTS

Comparing all participants of the virtual placenta study, no association between maternal tHcy and uPVV was observed. However, in IVF/ICSI pregnancies sub-analyses showed significantly negative associations between maternal tHcy in the 3rd and 4th quartile and uPVV trajectories (beta: -0.38 (95%CI -0.74 to -0.02) and beta: -0.42 (95% CI -0.78 to -0.05), respectively) with the 1st quartile as reference. Analysis in the total Predict cohort showed similar negative associations for the total study population.

DISCUSSION

Periconceptional high maternal tHcy levels are associated with smaller placental growth trajectories depicted as PV and uPVV in the first trimester of pregnancy. The stronger negative associations with uPVV in IVF/ICSI pregnancies underline the need for further investigation.