Effect of pregestational diabetes mellitus on first trimester placental characteristics: Three-dimensional placental volume and power Doppler indices

Objective

To investigate whether pregestational diabetes mellitus (DM) induces changes in vascular placental development detectable at first trimester.

Methods

This was a prospective case–control study in 69 women with pregestational DM and 94 controls undergoing first-trimester combined screening for aneuploidies. Maternal characteristics, fetal nuchal translucency thickness, maternal serum pregnancy-associated plasma protein A (PAPP-A) and free β human chorionic gonadotrophin (β-hCG) were evaluated. Three-dimensional ultrasound was used to measure placental volume and three dimensional power Doppler (3D-PD) placental vascular indices including: vascularization index (VI), flow index (FI) and vascularization flow index (VFI). Pregnancy-associated hypertensive complications (PAHC) and perinatal outcomes were analyzed. The total group of diabetic women and the group of diabetic women without PAHC were compared separately with the control group.

Results

3D-PD placental vascular indexes were significantly lower in women with DM than in controls (VI p = 0.007, FI p = 0.003 and VFI p = 0.04). These differences remained on excluding cases with PAHC in the DM group. No differences were found in placental volumes between the DM group and controls. Serum PAPP-A levels were also lower in diabetic women (p < 0.02) and negatively correlated with the degree of maternal metabolic control at first trimester.

Conclusions

Pregestational DM induces demonstrable alterations in first trimester placental development, with significantly reduced placental vascularization indices and PAPP-A values. This effect is independent of the later development of PAHC.     

Placental volume and vascular flow assessed by 3D power Doppler and adverse pregnancy outcomes

Objective

To estimate the utility of first-trimester 3D-placental volume and vascular flow indices in the prediction of adverse pregnancy outcomes.

Methods

A prospective cohort study including women with singleton pregnancies seen between 11 and 14 weeks as part of a screening program for aneuploidy. Placental volume and vascularization indices were obtained using 3D power Doppler imaging and the VOCAL technique. Placental volume (PV), Vascularization Index (VI), Flow Index (FI) and Vascularization Flow Index (VFI) were calculated. The adverse pregnancy outcomes investigated include preeclampsia (PE), gestational hypertension (GH) and small for gestational age (SGA). The predictive ability of each variable was evaluated using receiver-operating characteristic (ROC) curves.

Results

Of 388 women included, PE was seen in 30 (7.7%), GH in 37 (9.0%) and SGA in 31 (8.0%). Placental volume was not significantly different between the pregnancies with adverse outcomes and those without. The mean values of the VI and VFI were significantly lower in the pregnancies that developed PE but not in GH or SGA. The area under the ROC curve for the prediction of PE was 0.71, 0.69 and 0.70 for VI, FI and VFI, respectively.

Conclusion

The study confirms lower 3D power Doppler vascular flow indices in pregnancies that develop PE. The discriminatory ability of using these indices alone for predicting PE appears modest.     

Doppler study of uterine hemodynamics in women with unexplained infertility

Objective

To evaluate uterine artery blood flow using pulsed Doppler, and endometrial and subendometrial microvascularization using three-dimensional (3D) power Doppler, in women with unexplained infertility.

Study design

In a prospective clinical trial at a university teaching hospital, 40 women with unexplained infertility were compared to 40 fertile parous controls. In the mid-luteal (peri-implantation) phase, the endometrial thickness and volume, uterine artery pulsatility index (PI) and resistance index (RI), endometrial and subendometrial 3D power Doppler vascularization index (VI), flow index (FI), and vascularization flow index (VFI), and serum estradiol and progesterone levels were measured in both groups.

Results

The uterine artery PI (P = 0.003) and RI (P = 0.007) were significantly increased and the endometrial VI (P = 0.029), FI (P = 0.031), and VFI (P = 0.001) and subendometrial VI (P = 0.032), FI (P = 0.040), and VFI (P = 0.005) were significantly decreased in the unexplained infertility group. The endometrial thickness and volume and serum estradiol and progesterone levels, however, were not significantly different between the two groups.

Conclusion

Peri-implantation endometrial perfusion is impaired in women with unexplained infertility: Doppler study of uterine hemodynamics should therefore be considered in infertility work-up.     

Fractional volume of placental vessels in women with diabetes using a novel stereological 3D power Doppler technique

Objectives

In maternal diabetes the placenta is large with abnormal vascular development and increased villous volume. We used a novel stereological 3D power Doppler ultrasound technique to investigate differences in-vivo in the placental fractional volume of power Doppler signal (FrVol-PD) between women with and without diabetes.

Methods

We recruited 17 pregnant women with pre-gestational diabetes and 20 controls, all with anterior placentae. Each subject had ultrasound scans (Voluson 730 Expert) every 4 weeks between 12 and 32 weeks gestation. 3D power Doppler data were acquired and the placenta manually outlined using VOCAL (4D View). Power Doppler signal within the resultant volume was counted in a 3D manner adapting the random but systematic techniques used in stereology.

Results

Subjects were of similar age, BMI and parity. From 16 weeks the mean (SD) placental FrVol-PD was higher in the non-diabetic than in the diabetic group: 16 weeks – 0.125 (0.03) versus 0.108 (0.03), 20 weeks – 0.144 (0.05) versus 0.104 (0.03), 24 weeks – 0.145 (0.05) versus 0.128 (0.03), 28 weeks – 0.159 (0.05) versus 0.133 (0.02) and 32 weeks – 0.154 (0.03) versus 0.123 (0.04). These differences were significant between control and diabetic subjects [F(1,35) = 4.737, p = 0.036] and across gestation [F(3,140) = 8.294, p < 0.001].

Conclusion

Using a novel stereological-based ultrasound technique we have demonstrated the reliability of this application in the placenta. This technique shows promise for non-invasive assessment of placental function: further studies are required to identify if structural changes in a diabetic placenta are accompanied by altered function, manifest as reduced perfusion demonstrable in-vivo.     

Placental Vascular Sonobiopsy Using Three-dimensional Power Doppler Ultrasound in Normal and Growth Restricted Fetuses

ObjectiveTo investigate placental vascular sonobiopsy using three-dimensional (3D) power Doppler ultrasound to assess placental vascularization in normal and growth restricted fetuses.MethodsPlacental vascular sonobiopsy using 3D power Doppler ultrasound with the VOCAL imaging analysis program was performed on 208 normal fetuses between 12 and 40 weeks of gestation and 13 pregnancies with fetal growth restriction (FGR) at 22–39 weeks' gestation. Only pregnancies with an entirely visualized anterior placenta were included in the study. 3D power Doppler indices related to placental vascularization (vascularization index (VI), flow index (FI) and vascularization flow index (VFI)) were calculated in each placenta. Intra- and inter-class correlation coefficients and intra- and inter-observer agreements of measurements were assessed.ResultsA weak linear relationship was found between the gestational age and VI, FI, and VFI, respectively. VI values in 8 of 13 FGR pregnancies (61.5%), FI value in one FGR pregnancy (7.7%) and VFI values of 6 FGR pregnancies (46.2%) were below ?1.5SD of the reference ranges for VI, FI and VFI, respectively. After 32 weeks of gestation, VI, FI, and VFI values in 10 FGR pregnancies were significantly lower compared to 79 normal pregnancies, respectively (P < 0.01). All 3D power Doppler indices (VI, FI and VFI) showed a correlation greater than 0.85, with good intra- and inter-observer agreements.ConclusionOur findings suggest that placental vascular sonobiopsy using 3D power Doppler ultrasound may provide new information on the assessment of placental vascularization in normal and FGR pregnancies, while placental perfusion is reduced in FGR compared to normal pregnancy. However, the data and its interpretation in our study should be taken with some degree of caution because of the small number of FGR subjects studied. Further studies involving a larger sample size of FGR pregnancies are needed to confirm the usefulness of placental vascular sonobiopsy using 3D power Doppler ultrasound in clinical practice.     

Stereology of the placenta in type 1 and type 2 diabetes

Objective

To assess by stereology the placental structure in type 1 (T1DM) and type 2 (T2DM) diabetic pregnancies compared to normal non-diabetic (ND) controls.

Study design

Prospective case control study. Placentae were sampled in a systematic random fashion. Stereological analysis was performed using a computerised stereology programme (Image Pro 6.2, Media Cybernetics, Inc, Silver Spring MD, USA). Participants were matched for gender of infant and mode of delivery.

Main outcome measures

Volume, length and surface area of placental components; clinical outcome.

Results

Ten ND, eight T2DM and ten T1DM women consented to the study. There was no difference between the groups regarding maternal age, neonatal birth weight, or placental weight. On stereological examination, terminal villous volume was significantly increased in both diabetic groups compared to ND controls. Capillary volume and length was increased in T1DM pregnancies compared to ND and T2DM. Capillary length was increased in both diabetic groups compared to ND. When all diabetic groups were compared based on severity of glycaemia those with poor glycaemic control (HbA1c>7%) had higher placental capillary volume than those with good glycaemic control.

Conclusions

This study demonstrates an association between maternal diabetes and increased terminal villous volume. Additionally capillary volume and length is increased in the placentae of normally grown infants of T1DM diabetic mothers compared to non-diabetic controls. Maternal glycaemia appears to influence capillary, but not stromal, development. This suggests that factors other than glycaemia have a role in placental development in pre-gestational diabetes.     

Alteration of vascularization in preeclamptic placentas measured by three-dimensional power Doppler ultrasound

Abstract

Objective: To evaluate the alteration of vascularization in preeclamptic placentas measured by three-dimensional (3D) power Doppler ultrasound.

Methods: We performed a prospective study of placental vascularization and placental volume in 27 singleton pregnancies complicated by preeclampsia and 41 normal pregnancies from 27 to 39 weeks of gestation. The placental volume was analyzed using the VOCAL imaging analysis program and 3D power histogram was used to calculate the placental vascular indices including vascularization index (VI), flow index (FI) and vascularization flow index (VFI).

Results: Of the 27 preeclamptic pregnancies, 9 were complicated by intrauterine growth restriction and 15 were severe preeclampsia. Furthermore, nine of the preeclamptic pregnancies had abnormal end diastolic flow in the umbilical artery. No significant correlation was noted between the placental vascular indices and gestational age in normal pregnancies. The placental vascular indices including VI, FI and VFI were significantly lower in preeclamptic placentas compared with controls (VI, p?<?0.001; FI, p?=?0.022; VFI, p?<?0.001). Preeclamptic placental volume was also decreased compared with that of the controls (p?=?0.002). After adjustment for confounding factors, significant differences were observed in VI and placental volume. However, no correlation was found between 3D power Doppler vascular indices and umbilical artery flow velocities, and neither intrauterine growth restriction nor the severity of preeclampsia could be predicted by the vascular indices.

Conclusion: VI and placental volume are reduced in preeclamptic placenta. Placental vascular indices using 3D power Doppler ultrasound provide insights of placental vascularization in preeclampsia.     

Three-dimensional power Doppler indices of preeclamptic placentas correlated to umbilical artery Doppler and albuminuria

Purpose: To obtain three-dimensional power Doppler (3DPD) indices of placenta in pregnancies complicated with preeclampsia compared to normal pregnancies and correlated to umbilical artery Doppler and albuminuria.

Methods: A case-control study was conducted at Ain Shams University Maternity Hospital. Evaluation of placental vascular indices, vascularization index (VI), flow index (FI) and vascularization flow index (VFI), was done using 3DPD in 80 preeclampsia pregnancies compared to 80 normal controls.

Results: 3DPD indices (VI, FI and VFI) of preeclampsia cases revealed lower values than controls (p?p?Conclusion: 3DPD indices of placental vasculature revealed lower values in preeclamptic pregnancies than normal pregnancies. Further studies are needed to discuss the possible role of 3DPD in predicting preeclampsia.     

Evaluation of the utero-placental circulation by three-dimensional Doppler ultrasound in the second trimester of normal pregnancy.

OBJECTIVE: To define normative data with three-dimensional (3D) Doppler ultrasound in the second trimester spiral arteries and placental volume blood flow. METHODS: An entry criterion was a documented singleton pregnancy at 14-25 weeks with normal outcome. Each patient had a 3D power Doppler exam. Automatic volume acquisition of the placental and spiral arteries blood flow was obtained. We calculated vascularization index (VI), flow index (FI) and vascularization flow index (VFI). The patients were further divided into subgroups based on two gestational week intervals. The outcome measure was normal pregnancy outcome. RESULTS: One hundred ninety-nine patients were included in this study. Placental and spiral arteries vascular indices slowly increased indicating progressive development of vascular network and increase in the volume blood flow. The range for placental VI was 11.43-14.63, FI was 37.44-40 and VFI was 4.77-6.06. The range for spiral arteries VI was 19-20.91, FI was 39.66-41.1 and VFI was 8.49-8.92. The mean gestational age at delivery was 38.18 weeks. CONCLUSION: We defined normal 3D power Doppler vascular indices in pregnancies between 14 and 25 weeks of singleton gestation. The study indicated that placental and spiral arteries volume blood flow increased with the advancement of gestational age.     

Placental perfusion in normal pregnancy and early and late preeclampsia: A magnetic resonance imaging study

Objective

Our primary aim was to investigate if women with early or late preeclampsia have different placental perfusion compared with normal pregnancies. A secondary aim was to investigate if placental perfusion changes with increasing gestational age in normal pregnancy.

Methods

The study population included thirteen women with preeclampsia (five with early and eight with late preeclampsia) and nineteen women with normal pregnancy (ten with early and nine with late pregnancy). Early was defined as <34 weeks and late as ≥34 weeks gestation. All women underwent a magnetic resonance imaging (MRI) examination including a diffusion weighted sequence at 1.5 T. The perfusion fraction was calculated.

Results

Women with early preeclampsia had a smaller placental perfusion fraction (p = 0.001) and women with late preeclampsia had a larger placental perfusion fraction (p = 0.011), compared to women with normal pregnancies at the corresponding gestational age. The placental perfusion fraction decreased with increasing gestational age in normal pregnancies (p = 0.001).

Conclusion

Both early and late preeclampsia differ in placental perfusion from normal pregnant women. Observed differences are however in the opposite direction, suggesting differences in pathophysiology. Placental perfusion decreases with increasing gestational age in normal pregnancy.     

Comparison of placental three-dimensional power Doppler indices and volume in the first and the second trimesters of pregnancy complicated by gestational diabetes mellitus

Objective: To compare the changes of placental three-dimensional power Doppler indices and volume in the first and the second trimesters of pregnancy with gestational diabetes mellitus (GDM).

Methods: This was a prospective case-control study of singleton pregnancies with risk factors for GDM. Data on placental vascular indices including vascularization index (VI), flow index (FI), and vascularization flow index (VFI), as well as placental volume were obtained and analyzed during the first and the second trimesters between pregnant women with and without GDM.

Results: Of the 155 pregnant women enrolled, 31 developed GDM and 124 did not. VI and VFI were significantly lower in the GDM group during the first and second trimesters (VI: p?=?.023, and VFI: p?=?.014 in the first trimester; VI: p?=?.049, and VFI: p?=?.031 in the second trimester). However, the placental volume was similar in both the groups during the first trimester, while it was significantly increased in the GDM group during the second trimester (p?=?.022). There were no significant differences in FI and uterine artery pulsatility index between the two groups. After adjustments in multivariate logistic regression analysis, significant differences were observed in the first trimester VFI (adjusted odds ratio (OR) 0.76, 95% confidence interval (CI) 0.61–0.93), second trimester VFI (adjusted or 0.83, 95%CI 0.71–0.96), and second trimester placental volume (adjusted or 1.03, 95%CI 1.01–1.05).

Conclusions: Placental vascular indices can provide an insight into placental vascularization in GDM during early pregnancy. VFI rather than placental volume may be a sensitive sonographic marker in the first trimester of GDM placentas.     

Increased expression levels of E-cadherin,cytokeratin 18 and 19 observed in preeclampsia were not correlated with disease severity

Introduction

Preeclampsia is a pregnancy-specific disorder and placental factor(s) contribute to the pathogenesis of preeclampsia. Turnover of villous trophoblast is affected by impaired placental perfusion in preeclampsia. Expression and localisation of cadherins and cytokeratins are involved in the pathogenesis of preeclampsia. However, studies describing the associations between cadherins and cytokeratins in preeclampsia are limited. The aim of this study was to investigate the expression of E-cadherin, N-cadherin, cytokeratin 18 and cytokeratin 19 in placentae from women with preeclampsia in order to determine whether their expression differs with disease severity.

Methods

29 preeclamptic placentae and 25 normotensive placentae were included in this study. The expression of E-cadherin, cytokeratin 18, cytokeratin 19 andN-cadherin was quantified by immunohistochemistry and western blotting.

Results

E-cadherin, cytokeratin 18 and cytokeratin 19 were expressed predominantly in the syncytiotrophoblast of the placenta and the expression of E-cadherin, cytokeratin 18 and cytokeratin 19 was significantly increased in preeclampsia compared to normotensive pregnancies. However, there was no significant difference in expression between severe preeclampsia and mild preeclampsia. In addition, there was no difference in the expression of N-cadherin between preeclampsic and normotensive pregnancies.

Discussion

Our data demonstrated increased expression of E-cadherin, cytokeratin 18 and cytokeratin 19 in the syncytiotrophoblast of preeclamptic placentae, but this increase was not correlated with disease severity.

Conclusion

Our data suggests that E-cadherin and cytokeratins are involved in the pathogenesis of preeclampsia.     

Macrosomia has its roots in early placental development

Introduction

We sought to determine if early placental size, as measured by 3-dimensional ultrasonography, is associated with an increased risk of delivering a macrosomic or large-for-gestational age (LGA) infant.

Methods

We prospectively collected 3-dimensional ultrasound volume sets of singleton pregnancies at 11–14 weeks and 18–24 weeks. Birth weights were collected from the medical records. After delivery, the ultrasound volume set were used to measure the placental volume (PV) and placental quotient (PQ = PV/gestational age), as well as the mean placental and chorionic diameters (MPD and MCD, respectively). Placental measures were analyzed as predictors of macrosomia (birth weight ≥4000 g) and LGA (birth weight ≥90th percentile).

Results

The 578 pregnancies with first trimester volumes included 44 (7.6%) macrosomic and 43 (7.4%) LGA infants. 373 subjects also had second trimester volumes available. A higher PV and PQ were both significantly associated with macrosomia and LGA in both the first and second trimesters. Second trimester MPD was significantly associated with both outcomes as well, while second trimester MCD was only associated with LGA. The above associations remained significant after adjusting for maternal demographic variables such as race, ethnicity, age and diabetes. Adjusted models yielded moderate prediction of macrosomia and LGA (AUC: 0.71–0.77).

Conclusions

Sonographic measurement of the early placenta can identify pregnancies at greater risk of macrosomia and LGA. Macrosomia and LGA are already determined in part by early placental growth and development.     

Reproducibility of the study of placental vascularization by three-dimensional power Doppler

AIMS: To assess the reproducibility of 3D power Doppler study of placental vascularization in order to establish its methodological bases for its further application in normal and pathological pregnancies. METHODS: A prospective study was carried on 30 normal singleton pregnancies from 14 to 40 weeks. To evaluate placental vascularization 3D power Doppler was applied to obtain a "placental biopsy". The spherical volume acquired was analyzed using the VOCAL imaging program. Two consecutive measurements were taken from each patient by a single observer, obtaining a total of 60 datasets. Placental volume (PV), Mean Gray (MG), Vascularization Index (VI), Flow Index (FI) and Vascularization Flow Index (VFI) were calculated. Intra-class correlation coefficient (ICC) and intra-observer agreement was evaluated. RESULTS: PV and MG presented an ICC of 0.98 and 0.94 respectively, with differences approaching zero. All 3D power Doppler vascular indices (VI, FI and VFI) showed a correlation greater than 0.85, with a better intra-observer agreement for the flow indices (FI and VFI). CONCLUSIONS: Placental vascular biopsy through 3D power Doppler is a new and simple tool to routinely study placental vascularization in human pregnancy. Our results provide the validation of the technique demonstrating a good reproducibility of the 3D power Doppler parameters when applied to the study of the placental vascular tree in normal pregnancies.     

Fetoplacental vascular alterations associated with fetal growth restriction

Introduction

Placental functional impairment in pregnancies with fetal growth restriction (FGR) can arise from fetoplacental vascular abnormalities. We aimed to compare the micro and macrovasculature of placentas from normal pregnancies with those showing late onset FGR.

Methods

Placental arterial casts (n = 12 normal, 6 FGR) were prepared. Chorionic arterial number and inter-branch length were examined. Microvascular features were quantified in CD34-stained tissue sections obtained by systematic (n = 12 normal, 12 FGR) and targeted (n = 6 normal, 6 FGR) sampling from the placental periphery and centre.

Results

Adjusted for the weight of the placenta or the surface area of the chorionic plate, the number of chorionic arteries was similar in normal and FGR arterial casts. Inter-branch length per unit placental weight was greater in the first generation of arterial branches in FGR (p < 0.05). Villi in FGR placentas were more poorly vascularised, particularly at the periphery and in grossly visible hypovascular regions. Intermediate and terminal FGR villi in these areas exhibited reduced vessel lumens, loss of CD34, and infilling with CD34-negative cells of what appeared to be previously existing vascular spaces.

Conclusion

Differences in chorionic arterial branching patterns between normal and FGR placentas arise from differences in placental size. FGR placentas show microvascular regression and extreme hypovascularity in peripheral areas. These features may well limit the ability of the placenta to meet fetal nutrient requirements late in gestation. Targeted sampling is more effective than systematic random sampling in revealing vascular defects.     

JunB/Cyclin-D1 imbalance in placental mesenchymal stromal cells derived from preeclamptic pregnancies with fetal-placental compromise

Introduction

In the present study, we characterized the expression of Activating Protein 1 (AP-1) factors, key cell cycle regulators, in primary placental mesenchymal stromal cells (PDMSCs) derived from normal and preeclamptic (PE) pregnancies with fetal-placental compromise.

Methods

PDMSCs were isolated from control (n = 20) and preeclamptic (n = 24) placentae. AP-1 expression was determined by semi-quantitative RT-PCR (sqRT-PCR), Real Time PCR and Western Blot assay. PDMSCs were plated and JunB siRNA was performed. JunB and Cyclin-D1 expression were assessed by Real Time and Western Blot analyses.

Results

JunB expression was significantly increased while Cyclin-D1 expression was significantly down-regulated in PE relative to control PDMSCs. JunB siRNA was accompanied by JunB down-regulation and increased Cyclin-D1 in normal PDMSCs.

Conclusions

We described, for the first time, AP-1 expression in PDMSCs derived from physiological and PE placentae. Importantly, we demonstrated that JunB over-expression in PE-PDMSCs affects Cyclin-D1 regulation. Our data suggest a possible contribution of these pathological placental cells to the altered cell cycle regulation typical of preeclamptic placentae.     

Quantitative Analysis of Placental Vasculature by Three-Dimensional Power Doppler Ultrasonography in Normal Pregnancies From 12 to 40 Weeks of Gestation

Evaluate the distribution and variation of placental vascular indices according to gestational age and placental volume. From March to November 2007, three-dimensional (3D)-power Doppler ultrasound was performed in 295 normal pregnancies from 12 to 40 weeks of gestation. Using the same preestablished settings for all patients, power Doppler was applied to the placenta and placental volume was obtained by the rotational technique (VOCAL?). The 3D-power histogram was used to determine the placental vascular indices: vascularization index (VI), flow index (FI) and vascularization-flow index (VFI). The placental vascular indices were then plotted against gestational age and placental volume. All placental vascular indices showed constant distribution throughout gestation. A tendency for a reduction in placental vascular indices with increased placental volume was observed, but was only statistically significant when placental FI was considered (p < 0.05). All placental vascular indices estimated by 3D-power Doppler ultrasonography presented constant distribution throughout gestation, despite the increase in placental volume according to gestational age.     

Decreased expression of phosphorylated placental heat shock protein 27 in human and ovine intrauterine growth restriction (IUGR)

Introduction

Intrauterine growth restriction (IUGR) has been documented to increase placental apoptosis at term. HSP27 has been shown to be involved in the control of apoptosis. Our objective is to determine the expression of phosphorylated HSP27 (p-HSP27) in human IUGR, and to determine the role of HSP27 during gestation in an ovine hyperthermia induced model of IUGR.

Methods

Human placenta tissue samples were collected at term to quantify p-HSP27. Pregnant sheep were placed in hyperthermic (HT) conditions to induce IUGR. Placental tissues were collected at 55 (early), 95 (mid-gestation) and 130 (near-term) days gestational age (dGA) to determined phosphorylated and total HSP27 across the development of IUGR.

Results

Phosphorylated HSP27 was significantly reduced in human placenta IUGR compared to controls at term. HSP27 was increased throughout gestation during the development of IUGR in the sheep. P-HSP27 was increased in early gestation (55 dGA), and decreased near term (130 dGA). The near term decrease was localized to the trophoblast cells of the placenta.

Discussion and conclusion

We conclude that decreased p-HSP27 at term is present when placental apoptosis is increased during IUGR. This could be a factor leading to the decreased placental weight observed during IUGR.     

Placental volume and other first-trimester outcomes: are there differences between fresh embryo transfer,frozen-thawed embryo transfer and natural conception?

Research question

Does mode of conception influence placental volume and other first-trimester outcomes?

Doppler evaluation of the effects of propofol,etomidate and alphaxalone on fetoplacental circulation hemodynamics in the pregnant ewe

Introduction

Umbilical artery (UA) hemodynamics reflect blood flow and vascular resistance in the placental circulation. We examined non-invasively the hemodynamic effects of propofol, etomidate, and alphaxalone on the placental circulation of a sheep model by means of UA Doppler ultrasonography.

Methods

Eleven sheep fetuses were examined at 90–109 days of gestation. UA Doppler ultrasound was performed before and after administration of a single intravenous bolus of propofol, etomidate, or alphaxalone. UA Doppler velocities (peak systolic velocity, end diastolic velocity, and mean velocity), vascular indices (pulsatility index, resistance index, and S/D ratio), blood flow, and fetal heart rate were recorded during the experimental period and UA Doppler waveforms were characterized.

Results

A laminar, parabolic, low resistance flow was observed in the UA of the sheep fetuses. No statistically significant changes were observed in the UA Doppler waveforms or in the UA Doppler hemodynamics after anesthesia induction.

Discussion

Changes in placental vascular resistance may alter the corresponding UA Doppler waveforms. When resistance in the fetal placenta increases, blood flow in the UA becomes more pulsatile. In the present study, umbilical arteries showed a parabolic flow with low resistance in all cases, as it occurs in normal human pregnancy. The administration of these anesthetics did not cause abnormalities in the normal UA Doppler pattern, inducing no changes in the resistance of the placenta in any case.

Conclusion

These results suggest that intravenous anesthetic induction with propofol, etomidate, or alphaxalone does not cause significant detrimental effects on the placental circulation of the pregnant ewe.