Clustering of maternal-fetal clinical conditions and outcomes and placental lesions

Using latent variable modelling to identify etiological heterogeneity in preterm delivery

AIMS

To identify a subgroup of mothers at high risk of preterm delivery, defined by empirical classes of multimorbidity and recurrence across three consecutive births.

METHODS

The data were extracted from the perinatal data collection (PDC) of all inpatient live births (n = 435 912) occurring in the Australian state of Queensland between January 2009 and December 2015. Within this data, a total of 7714 primiparous mothers delivered three consecutive singleton live births (total births = 23 142), and comprise the sample for all analyses.

RESULTS

The LCA indicated a four-class solution fit the data best at each time point, including (i) a 'normative' or healthy class with little morbidity (including >80% of the sample at each birth); (ii) a preterm, high morbidity class (<2% of the sample); (ii) a delivery morbidity class (4-8% of the sample); and (iii) preterm, low morbidity class (5-6% of the sample). Each group exhibited unique and consistent associations with maternal and pregnancy-related factors across births. After accounting for these factors, the high morbidity class and preterm, low morbidity class strongly predicted these same classes across consecutive births, and from birth 1 to birth 3 (second-order transition).

CONCLUSIONS

A small but highly morbid class of neonatal deliveries emerged, exhibiting strong continuity across consecutive births (odds ratios >10), independent of a range of maternal and pregnancy-related factors. This group of women, if subject to further investigation, could provide valuable insight into the aetiology of prematurity and associated morbidity, perhaps providing information to improve birth outcomes among all women.

Shallow Placentation: A Distinct Category of Placental Lesions

OBJECTIVE

Shallow placental implantation (SPI) features placental maldistribution of extravillous trophoblasts and includes excessive amount of extravillous trophoblasts, chorionic microcysts in the membranes and chorionic disc, and decidual clusters of multinucleate trophoblasts. The histological lesions were previously and individually reported in association with various clinical and placental abnormalities. This retrospective statistical analysis of a large placental database from high-risk pregnancy statistically compares placentas with and without a composite group of features of SPI.

STUDY DESIGN

Twenty-four independent abnormal clinical and 44 other than SPI placental phenotypes were compared between 4,930 placentas without (group 1) and 1,283 placentas with one or more histological features of SPI (composite SPI group; group 2). Placentas were received for pathology examination at a discretion of obstetricians. Placental lesion terminology was consistent with the Amsterdam criteria, with addition of other lesions described more recently.

RESULTS

Cases of group 2 featured statistically and significantly (p < 0.001after Bonferroni's correction) more common than group 1 on the following measures: gestational hypertension, preeclampsia, oligohydramnios, polyhydramnios, abnormal Dopplers, induction of labor, cesarean section, perinatal mortality, fetal growth restriction, stay in neonatal intensive care unit (NICU), congenital malformation, deep meconium penetration, intravillous hemorrhage, villous infarction, membrane laminar necrosis, fetal blood erythroblastosis, decidual arteriopathy (hypertrophic and atherosis), chronic hypoxic injury (uterine and postuterine), intervillous thrombus, segmental and global fetal vascular malperfusion, various umbilical cord abnormalities, and basal plate myometrial fibers.

CONCLUSION

SPI placentas were statistically and significantly associated with 48% abnormal independent clinical and 51% independent abnormal placental phenotypes such as acute and chronic hypoxic lesions, fetal vascular malperfusion, umbilical cord abnormalities, and basal plate myometrial fibers among others. Therefore, SPI should be regarded as a category of placental lesions related to maternal vascular malperfusion and the "Great Obstetrical Syndromes."

KEY POINTS

· SPI reflects abnormal distribution of extravillous trophoblasts.. · SPI features abnormal clinical and placental phenotypes.. · SPI portends increased risk of complicated perinatal outcome..

Machine learning-based placental clusters and their associations with adverse pregnancy outcomes

BACKGROUND

Placental abnormalities have been described in clinical convenience samples, with predominately adverse outcomes. Few studies have described placental patterns in unselected samples.

OBJECTIVE

We aimed to investigate associations between co-occurring placental features and adverse pregnancy outcomes in a prospective cohort of singletons.

METHODS

Data were from the Safe Passage study (U.S. and South Africa, 2007-2015). Before 24 weeks' gestation, participants were randomly invited to donate placental tissue at delivery for blinded, standardised pathological examination. We used hierarchical clustering to construct statistically derived groups using 60 placental features. We estimated associations between the placental clusters and select adverse pregnancy outcomes, expressed as unadjusted and adjusted risk ratios (RRs) and robust 95% confidence intervals (CI).

RESULTS

We selected a 7-cluster model. After collapsing 2 clusters to form the reference group, we labelled the resulting 6 analytic clusters according to the overarching category of their most predominant feature(s): severe maternal vascular malperfusion (n = 117), fetal vascular malperfusion (n = 222), other vascular malperfusion (n = 516), inflammation 1 (n = 269), inflammation 2 (n = 175), and normal (n = 706). Risks for all outcomes were elevated in the severe maternal vascular malperfusion cluster. For instance, in unadjusted analyses, this cluster had 12 times the risk of stillbirth (RR 12.07, 95% CI 4.20, 34.68) and an almost doubling in the risk of preterm delivery (RR 1.93, 95% CI 1.27, 2.93) compared with the normal cluster. Small infant size was more common among the abnormal clusters, with the highest unadjusted RRs observed in the fetal vascular malperfusion cluster (small for gestational age birth RR 2.99, 95% CI 2.24, 3.98, head circumference <10th percentile RR 2.86, 95% CI 1.60, 5.12). Upon adjustment for known risk factors, most RRs attenuated but remained >1.

CONCLUSION

Our study adds to the growing body of epidemiologic research, finding adverse pregnancy outcomes may occur through etiologic mechanisms involving co-occurring placental abnormalities.

CD34 immunostain increases sensitivity of the diagnosis of fetal vascular malperfusion in placentas from ex-utero intrapartum treatment

OBJECTIVES

EXIT (ex-utero intrapartum treatment) procedure is a fetal survival-increasing modification of cesarean section. Previously we found an increase incidence of fetal vascular malperfusion (FVM) in placentas from EXIT procedures which indicates the underlying stasis of fetal blood flow in such cases. This retrospective analysis analyzes the impact of the recently introduced CD34 immunostain for the FVM diagnosis in placentas from EXIT procedures.

METHODS

A total of 105 placentas from EXIT procedures (48 to airway, 43 to ECMO and 14 to resection) were studied. In 73 older cases, the placental histological diagnosis of segmental FVM was made on H&E stained placental sections only (segmental villous avascularity) (Group 1), while in 32 most recent cases, the CD34 component of a double E-cadherin/CD34 immunostain slides was also routinely used to detect the early FVM (endothelial fragmentation, villous hypovascularity) (Group 2). Twenty-three clinical and 47 independent placental phenotypes were compared by χ² or ANOVA, where appropriate.

RESULTS

There was no statistical significance between the groups in rates of segmental villous avascularity (29 vs. 34%), but performing CD34 immunostain resulted in adding and/or upgrading 12 more cases of segmental FVM in Group 2, thus increasing the sensitivity of placental examination for FVM by 37%. There were no other statistically significantly differences in clinical (except for congenital diaphragmatic hernias statistically significantly more common in Group 2, 34 vs. 56%, p=0.03) and placental phenotypes, proving the otherwise comparability of the groups.

CONCLUSIONS

The use of CD34 immunostain increases the sensitivity of placental examination for FVM by 1/3, which may improve the neonatal management by revealing the increased likelihood of the potentially life-threatening neonatal complications.

Clinical Characteristics of Mother-Infant Dyad and Placental Pathology in COVID-19 Cases in Predominantly African American Population

Objective  In this currently evolving coronavirus disease 2019 (COVID-19) pandemic, the evidence is scarce about the impact of COVID-19 infection on women in labor and neonates in an inner city African-Americans (AA) population. The objective of this study was to evaluate the clinical outcomes and placental pathology in mother-infant dyads in COVID-19 cases. Study Design  Retrospective chart review was conducted on 34 COVID-19 positive mother-infant dyads to study their baseline characteristics and outcomes. Placental pathology was reviewed by two perinatal pathologists. Results  COVID-19 was noted in 3% of pregnant women who delivered in our institution. The majority (82%) of them were asymptomatic. Out of the four mothers who were symptomatic, only three (9%) required supplemental oxygen. None of them required invasive ventilation. All the neonates tested negative for COVID-19 at 24 hours of age. There were no gross or microscopic pathological abnormalities detected that could be definitely associated with any COVID-19 related complications during pregnancy in any of the 34 placentas. Conclusion  COVID-19 does not appear to increase morbidity and mortality among pregnant women and their neonates in a predominantly AA population. Our study did not find any evidence of vertical transmission of COVID-19 infection nor any specific findings on placental pathology. Key Points Majority of women infected by coronavirus disease 2019 (COVID-19) during labor were asymptomatic.None of the newborns tested positive for COVID-19 at 24 hours of age.Placental pathology findings were nonspecific in COVID-19 mothers.

Placenta Creta: A Spectrum of Lesions Associated with Shallow Placental Implantation

Background

On placental histology, placenta creta (PC) ranges from clinical placenta percreta through placenta increta and accreta (clinical and occult) to myometrial fibers with intervening decidua. This retrospective study aimed to investigate the clinicopathologic correlations of these lesions.

Methods

A total of 169 recent consecutive cases with PC (group 1) were compared with 1661 cases without PC examined during the same period (group 2). The frequencies of 25 independent clinical and 40 placental phenotypes were statistically compared between the groups using chi-square test or analysis of variance where appropriate.

Results

Group 1 placentas, as compared with group 2 placentas, were statistically significantly (p < 0.05) associated with caesarean sections (11.2% vs. 7.5%), antepartum hemorrhage (17.7% vs 11.6.%), gestational hypertension (11.2% vs 4.3%), preeclampsia (11.8% vs 2.6%), complicated third stage of labor (18.9% vs 6.4%), villous infarction (14.2% vs 8.9%), chronic hypoxic patterns of placental injury, particularly the uterine pattern (14.8%, vs 9.6%), massive perivillous fibrin deposition (9.5% vs 5.3%), chorionic disc chorionic microcysts (21.9% vs 15.9%), clusters of maternal floor multinucleate trophoblasts (27.8% vs 21.2%), excessive trophoblasts of chorionic disc (24.3% vs 17.3%), segmental fetal vascular malperfusion (27.8% vs 19.9%), and fetal vascular ectasia (26.2% vs 15.2%).

Conclusion

Because of the association of PC with gestational hypertensive diseases, acute and chronic placental hypoxic lesions, increased extravillous trophoblasts in the chorionic disc, chorionic microcysts, and maternal floor trophoblastic giant cells, PC should be regarded as a lesion of abnormal placental implantation and abnormal trophoblast invasion rather than decidual deficiency only.

Placental Compartmentalization of Lipid Metabolism: Implications for Singleton and Twin Pregnancies

The study of placental lipid metabolism in uncomplicated pregnancies has not been developed in the literature to date. Its importance lies in expanding the knowledge of placental function to enable comparison with pathological pregnancies in future research. The aim of the present study was to compare the lipid metabolic activity and storage of the maternal and fetal sides of the placenta in healthy pregnancies. Moreover, we compare singleton vs. twin pregnancies to determine if placental metabolic needs differ. We analyzed placental explants from uncomplicated pregnancies, 20 from singleton and 8 from bichorial-biamniotic twin pregnancies (n = 28). Six cotyledon fragments were collected from each placenta at different distances from the umbilical cord, three close to the chorionic plate (hereinafter, we will refer to them as "fetal side") and another three close to the anchoring villi into the decidua basalis (referred to as "maternal side"). The samples were analyzed for quantitative assay placental fatty acid oxidation (FAO) and esterification (FAE) activities and triglyceride levels. The location of lipid storage in the chorionic villi was assessed by Oil red-O staining. Placental fatty acid oxidation did not show differences when comparing the maternal and fetal sides of the placenta or between single and twin pregnancies. When comparing placental sides, FAE was increased twofold in the maternal side compared to the fetal side of the placenta (P = 0.013). The tendency for lipogenesis in the placenta was exemplified by the FAE/FAO ratio, which was a 37.1% higher on the maternal side (P = 0.019). Despite this, triglyceride levels were five times higher in the fetal side than in the maternal one (P = 0.024). When analyzing singleton vs. twins, FAE was superior in the fetal side in multiple pregnancies (× 2.6, P = 0.007) and the FAE/FAO ratio was significantly higher in twins than in singleton pregnancies, on both sides of the placenta. Despite this finding, triglyceride levels were similar in twin and singleton pregnancies. Comparing the placentas of twins in the same pregnancy, there were no differences in lipid metabolism (FAO or FAE) or placental triglyceride levels between the two co-twins. Using Oil red-O staining, lipid storage in chorionic villi was found to be located on the syncytiotrophoblast cells and not in the connecting axis. The maternal side of the placenta is more active in the esterification of fatty acids, while the storage of neutral lipids concentrates on the fetal side. Moreover, multiple gestations have increased esterification without changes in the concentration of placental triglycerides, probably due to a higher transfer to the fetal circulation in response to the greater energy demand from twin fetuses.

Temporal heterogeneity of placental segmental fetal vascular malperfusion: timing but not etiopathogenesis

Clinicopathologic correlations of segmental villous avascularity and other histological lesions of segmental fetal vascular malperfusion (SFVM) were analyzed retrospectively to determine whether lesions of various durations reflect different etiopathogeneses. The frequencies of 25 independent clinical and 43 placental phenotypes were statistically compared by ANOVA or Chi-square among 3 groups containing a total of 378 placentas with SFVM: group 1 contained 44 cases of recent SFVM (endothelial fragmentation, villous hypovascularity by CD34 immunostain, and/or stromal vascular karyorrhexis); group 2 contained 264 cases of established SFVM (clusters of avascular villi); and group 3 contained 70 cases of remote SFVM (villous mineralization). Statistically significant differences among the three study groups (p Bonferroni < 0.002) were found in four clinical variables (gestational age, frequencies of macerated stillbirth, induction of labor, and cesarean section) and in five placental variables (frequencies of fetal vascular ectasia, stem vessel luminal vascular abnormalities, diffusely increased extracellular matrix in chorionic villi, chorionic disk extravillous trophoblast microcysts, and excessive extravillous trophoblasts in the chorionic disc). In summary, the absence of statistically significant differences between the study groups regarding the most common causes of SFVM (hypertensive conditions of pregnancy, diabetes mellitus, fetal anomalies, and clinical and pathological features of umbilical cord compromise) is evidence that the three types of SFVM reflect temporal heterogeneity rather than etiopathogenesis. This evidence can be used to date the onset of fetal vascular malperfusion before delivery or stillbirth. The coexistence of different SVFM lesions of various durations indicates ongoing or repeat occurrences of FVM rather than single episodes.

Patterns of Placental Injury in Congenital Anomalies in Second Half of Pregnancy

BACKGROUND

Placental pathology in fetal congenital anomalies in second half of pregnancy is largely unknown.

METHODS

Twenty-six clinical and 45 independent placental phenotypes from pregnancies ≥20 weeks of gestation with congenital anomalies divided into 4 groups were retrospectively compared with analysis of variance or χ ² with 3 degrees of freedom and with Bonferroni correction for multiple comparisons: group 1 : 112 cases with heart malformations (with or without chromosomal anomalies), group 2 : 41 cases with abnormal karyotypes and anomalies other than heart malformations, group 3 : 87 cases with intrathoracic or intraabdominal mass-forming anomalies (mostly congenital diaphragmatic hernias and adenomatoid airway malformation), and group 4 : 291 miscellaneous cases with mostly skeletal, renal, and central nervous system anomalies not fulfilling the criteria of inclusion into groups 1 to 3.

RESULTS

Eight of 26 clinical (30.8%) and 16 of 45 (35.5%) placental phenotypes varied statistically significantly among the 4 groups (P <  .05), of those, 7 (26.9%) and 4 (8.9%), respectively, remained statistically significant after Bonferroni correction (P Bonferroni ≤  .002). Those placental phenotypes were placental weight, chorionic disc chorionic microcysts, fetal vascular ectasia, and luminal vascular abnormalities of chorionic villi.

CONCLUSIONS

Fetal anomalies in second half of pregnancy feature abnormal clinical phenotypes much more frequently than abnormal placental phenotypes. Chromosomal abnormalities with or without heart malformations tend to feature villous edema, and erythroblastosis of fetal blood, likely due to fetal heart failure. Mass-forming fetal anomalies feature placental histological lesions of shallow placental implantation, diffuse chronic hypoxic patterns of placental injury, and lesions of fetal vascular malperfusion, likely stasis-induced.

Segmental villous mineralization: A placental feature of fetal vascular malperfusion

INTRODUCTION

This retrospective analysis was performed to find out if clusters of mineralized chorionic villi can be regarded as an independent feature of fetal vascular malperfusion (FVM).

METHODS

Of all 1698 placentas reviewed by the author during the last 10 years, 39 (2.3%) showed clusters of mineralized chorionic villi (Group 1), 100 cases (5.9%) showed randomly scattered mineralized chorionic villi with without clustering (Group 2), and the remaining 1559 placentas showed no villous mineralization (comparative Group 3). In doubtful cases, histochemistry stains were performed to determine the pattern of villous mineralization. Twenty three independent clinical and 43 placental variables were statistically compared among the groups: descriptive statistics (Chi-square, Fisher test or signed rank test), and logistics regression model.

RESULTS

Clinically, Group 1 featured shorter gestational age than Group 2, and in addition to shorter gestational age, more common oligohydramnios, polyhydramnios, induction of labor, macerated stillbirth and fetal growth restriction than Group 3. Of placental variables, fetal vascular ectasia, and clusters of avascular chorionic villi were more common in Group 1 than in Group 2, and in addition, segmental villous stromal vascular karyorrhexis was more common than in Group 3. By the logistics regression mode, segmental villous mineralization was independently associated with other histological features of FVM as a group and particularly with clusters of sclerotic chorionic villi.

DISCUSSION

FVM is characterized by temporal heterogeneity, i.e. coexistence of lesions of various duration, and strongly and independently correlates with clusters of mineralized chorionic villi. Therefore, segmental villous mineralization should be included into the category of segmental FVM. It can be seen even in totally fibrotic placentas of prolonged stillbirth when other histological features of segmental vascular malperfusion can be obscured by global villous sclerosis.

Histological Features of Shallow Placental Implantation Unify Early-Onset and Late-Onset Preeclampsia

Preeclampsia is distinguishable from other hypertensive conditions of pregnancy by its high rates of decidual arteriopathy, the uterine type of chronic hypoxic placental injury, the occurrence of villous infarctions, and clusters of multinucleate trophoblasts in the maternal floor. To retrospectively study the clinical and placental phenotypes of 230 women with early-onset preeclampsia, 261 women with late-onset preeclampsia, and 5059 women without hypertension in pregnancy (comparative group), 24 clinical and 46 placental phenotypes were statistically compared (analysis of variance, χ² with Bonferroni correction). The frequency of decidual arteriopathy (both hypertrophic and atherosis), patterns of chronic hypoxic placental injury, villous infarction, membrane laminar necrosis, membrane microscopic chorionic pseudocysts, clusters of maternal floor multinucleated trophoblasts, excessive number of extravillous trophoblasts, and intervillous thrombi was strikingly higher in both late-onset preeclampsia and early-onset preeclampsia than in the comparative group without hypertension in pregnancy. All 3 patterns of chronic hypoxic placental injury were 2- to 3-fold more common in preeclampsia. Although the preuterine pattern was as common in early-onset preeclampsia as it was in late-onset preeclampsia, the postuterine pattern was 2-fold more common in early-onset preeclampsia, and chronic villitis of unknown etiology was more common in late-onset preeclampsia than in the other 2 groups. Features of shallow placental implantation occurred at the same frequency in early-onset preeclampsia as in late-onset preeclampsia, which reflects an underlying common pathological mechanism in both subgroups of preeclampsia, while hypoxic lesions and patterns of placental injury were more common in early-onset preeclampsia than in late-onset preeclampsia, which correlates with more severe clinical outcomes of the former.

Placental examination in nonmacerated stillbirth versus neonatal mortality

AIM

To retrospectively statistically compare clinical and placental phenotypes of nonmacerated fetuses and live-born perinatal deaths in 3rd trimester pregnancies.

METHODS

Twenty-five clinical and 47 placental phenotypes were statistically compared among 93 cases of nonmacerated (intrapartum, or recent antepartum death) 3rd trimester fetal deaths (Group 1), 118 3rd trimester neonatal deaths (Group 2) and 4285 cases without perinatal mortality (Group 3).

RESULTS

Sixteen clinical and placental phenotypes were statistically significantly different between Group 3 and the two groups of perinatal deaths, which included eight placental phenotypes of fetal vascular malperfusion and eight other placental phenotypes of various etiology (amnion nodosum, 2-vessel umbilical cord, villous edema, increased extracellular matrix of chorionic villi, erythroblasts in fetal blood and trophoblastic lesions of shallow placentation). Statistically significant differences between Groups 1 and 2 were scant (oligohydramnios, fetal malformations, cesarean sections, hypercoiled umbilical cord and amnion nodosum being more common in the latter, and retroplacental hematoma more common in the former).

CONCLUSION

Placental examination in neonatal mortality shows thrombotic pathology related to umbilical cord compromise and features of shallow placental implantation that are similar to those in nonmacerated stillbirth; however, the features of placental abruption were more common in recent antepartum death, as were the features related to neonatal congenital malformations in neonatal deaths.

Decidual arteriolopathy with or without associated hypertension modifies the underlying histomorphology in placentas from diabetic mothers

AIM

The aim of this study was to retrospectively document the impact of hypertensive conditions in pregnancy and decidual arteriolopathy on the patterns of placental injury in maternal diabetes mellitus (MDM).

METHODS

Among all 5248 > 20 weeks' placentas, the frequencies of 19 selected clinical and 24 placental phenotypes were compared between 287 MDM placentas and 4961 remaining placentas (control group [CG]) before and after further exclusion of 85 and 611 patients with hypertensive conditions (gestational hypertension, pre-eclampsia, chronic hypertension).

RESULTS

Cesarean section rate, heavy placentas, decidual arteriolopathy, microscopic chorionic pseudocysts, and chorangiosis were more common in MDM than in the CG both before and after exclusion of hypertensive conditions. The frequencies of preuterine patterns of chronic hypoxic placental injury and plasma cell deciduitis became statistically significant only after exclusion of hypertensive conditions.

CONCLUSION

Hypertensive conditions of pregnancy may obscure the underlying preuterine placental hypoxic pattern in MDM placentas. Even in normotensive patients, decidual arteriolopathy, and shallow placental implantation significantly impact placental histomorphology in MDM.

Altered Biomarkers in Trophoblast Cells Obtained Noninvasively Prior to Clinical Manifestation of Perinatal Disease

A contributing factor to poor placental perfusion, leading to intrauterine growth restriction and preeclampsia, is the failure of invading extravillous trophoblast (EVT) cells to remodel the maternal uterine arteries during the first and second trimesters of pregnancy. Noninvasive assessment of EVT cells in ongoing pregnancies is possible beginning three weeks after conception, using trophoblast retrieval and isolation from the cervix (TRIC). Seven proteins were semi-quantified by immunofluorescence microscopy in EVT cells obtained between gestational weeks 6 and 20 from pregnancies with normal outcomes (N = 29) and those with intrauterine growth restriction or preeclampsia (N = 12). Significant differences were measured in expression of PAPPA, FLT1, ENG, AFP, PGF, and LGALS14, but not LGALS13 or the lineage marker KRT7. These findings provide for the first time direct evidence of pathology-associated protein dysregulation in EVT cells during early placentation. The TRIC platform provides a novel approach to acquire molecular signatures of EVT cells that can be correlated with pregnancy outcome.

Chorangiosis of Chorionic Villi: What Does It Really Mean?

Chorangiosis has been regarded as a result of low-grade placental hypoxia associated with pregnancy risk factors and abnormal outcomes. It is unknown whether these are a consequence of chorangiosis itself or of associated other placental pathology.Context.—

To prove that chorangiosis itself does not portend an increased risk for pregnancy unless associated with other placental pathology.Objective.—

This retrospective statistical study analyzes 1231 consecutive placentas with diffuse or focal hypervascularity of chorionic villi: 328 with preuterine pattern of chronic hypoxic placental injury (group 1), 297 with uterine type of chronic hypoxic placental injury (group 2), and 606 cases with chorangiosis (group 3) not fulfilling the inclusion criteria for groups 1 or 2.Design.—

Group 2, with 33 cases of chorangiosis (11.1%), featured 10 and 11 statistically significant highest percentages of abnormal clinical and placental variables, respectively; group 3 featured the highest percentages of multiple pregnancy, the heaviest placentas, and the most common acute chorioamnionitis, fetal inflammatory response; and group 1 had the highest proportion of mild erythroblastosis of fetal blood. When comparing groups 1 and 3, 21 of 29 clinical risk factors/outcomes (72.4%) and 30 of 41 placental variables (73.2%) were more common in group 1.Results.—

Presence of diffuse hypoxic patterns of placental injury adds prognostically negative significance to increased vascularity of chorionic villi. Chorangiosis without those patterns portends minimal risk for the pregnancy, and is associated with significantly fewer pregnancy risk factors, abnormal outcomes, and other placental abnormalities.Conclusions.—

Clustering and classical analysis of clinical and placental phenotypes in fetal growth restriction and constitutional fetal smallness

This study aims to determine whether placental examination can be used to distinguish between pathologic fetal growth restriction (FGR) and constitutional fetal smallness. Data were extracted from a clinicoplacental database of high risk pregnancies during the period 1994-2013. These data were used to compare the 590 consecutive cases having birth weights below the 10th percentile with the 5201 remaining cases having gestational ages ≥20 weeks. The authors analyzed 20 clinical and 46 placental phenotypes using classical statistics, clustering analysis, and multidimensional scaling. Of the low-birth-weight babies, the following types of cases were compared: Four categories of placental phenotypes (those with features of poor uteroplacental perfusion, postuterine placental pathology, chronic inflammation, and a mixed category) better defined the presumably true FGR than did the clinical phenotypes. Maternal smoking and oligohydramnios were associated with fewer abnormal placental phenotypes than were maternal hypertensive diseases and abnormal Dopplers. Early-onset cases of fetal smallness clustered with placental features of poor uteroplacental perfusion, whereas late onset cases did not. Placental examination helps to retrospectively distinguish constitutionally small fetuses from those that are pathologically growth restricted. The latter correlate best with the clinical risk for FGR and with early-onset FGR. This correlation may have prognostic significance for the child and for future pregnancies, since hypoxic placental lesions can occur without clinical risk factors but with a tendency to recur in future pregnancies.

Hypoplastic left heart syndrome is associated with structural and vascular placental abnormalities and leptin dysregulation

INTRODUCTION

Hypoplastic left heart syndrome (HLHS) is a severe cardiovascular malformation (CVM) associated with fetal growth abnormalities. Genetic and environmental factors have been identified that contribute to pathogenesis, but the role of the placenta is unknown. The purpose of this study was to systematically examine the placenta in HLHS with and without growth abnormalities.

METHODS

HLHS term singleton births were identified from a larger cohort when placenta tissue was available. Clinical data were collected from maternal and neonatal medical records, including anthropometrics and placental pathology reports. Placental tissues from cases and controls were analyzed to assess parenchymal morphology, vascular architecture and leptin signaling.

RESULTS

HLHS cases (n = 16) and gestational age-matched controls (n = 18) were analyzed. Among cases, the average birth weight was 2993 g, including 31% that were small for gestational age. When compared with controls, gross pathology of HLHS cases demonstrated significantly reduced placental weight and increased fibrin deposition, while micropathology showed increased syncytial nuclear aggregates, decreased terminal villi, reduced vasculature and increased leptin expression in syncytiotrophoblast and endothelial cells.

DISCUSSION

Placentas from pregnancies complicated by fetal HLHS are characterized by abnormal parenchymal morphology, suggesting immature structure may be due to vascular abnormalities. Increased leptin expression may indicate an attempt to compensate for these vascular abnormalities. Further investigation into the regulation of angiogenesis in the fetus and placenta may elucidate the causes of HLHS and associated growth abnormalities in some cases.

Do Placental Histopathologic Characteristics Differ with Gestational Ages in Preterm and Term Deliveries?

The study aim is to evaluate the placental histopathological characteristics and maternal risk factors in preterm and term births according to their weeks of gestation. We designed a prospective study involving a patient population (n = 355) composed of pregnant women who delivered preterm (n = 216) and term neonates (n = 139). The preterm births were divided into three groups as extremely (n = 22), moderate (n = 96) and late preterm (n = 98) births. The statistical analyses were performed using SPSS version 15 software. There was significant difference regarding maternal vascular underperfusion and inflammation in the extremely preterm group compared with the other groups (P = 0.001), but fetal vascular obstruction and villitis of unknown etiology were not found significantly different. According to our study results, the careful examination of the placenta of premature babies, particularly those of extremely preterm births, should be part of routine obstetrical management to determine the causes of preterm birth.

Comparison of placental pathology in preterm, late-preterm, near-term, and term births

OBJECTIVE

The purpose of this study was to determine whether placental pathologic condition supports the recent suggestion of subcategorizing preterm and term births into smaller gestational age subgroups with different perinatal mortality and morbidity rates.

STUDY DESIGN

Twenty-seven clinical and 43 placental phenotypes were retrospectively compared in 4617 third-trimester births: 1332 preterm pregnancies (28-33 weeks' gestation), 1066 late preterm pregnancies (34-36 weeks' gestation), 940 near-term pregnancies (37-38 weeks' gestation), and 1279 term pregnancies (≥39 weeks' gestation).

RESULTS

Acute inflammatory pattern of placental injury was seen mostly at both gestational sides of the third trimester; the clinical conditions linked to in utero hypoxia (preeclampsia, diabetes mellitus, fetal growth restriction) and their placental associations (atherosis, membrane chorionic microcysts, chorangiosis, intervillous thrombi) were associated statistically significantly with mid third trimester. Acute fetal distress (abnormal fetal heart tracing and clinical and histologic meconium) were increasing with gestational age and were statistically significantly most common in full-term pregnancies.

CONCLUSION

Differences in placental pathologic condition among the 4 subgroups of third-trimester pregnancy not only challenge the use of an arbitrary cutoff point of 37 weeks' gestation that separates the preterm birth and term birth but also further support separation of late preterm births from preterm births and term births from near-term births. Based on placental pathologic condition, chronic uteroplacental malperfusion is the dominating etiopathogenetic factor in the mid third trimester (late preterm and near-term births), and acute fetal distress is the factor in full-term births. This obscures relative frequencies of perinatal death and management modalities in the third trimester.

Hypoxic patterns of placental injury: a review

CONTEXT

In utero hypoxia is an important cause of perinatal morbidity and mortality and can be evaluated retrospectively to explain perinatal outcomes, to assess recurrence risk in subsequent pregnancies, and to investigate for medicolegal purposes by identification of many hypoxic placental lesions. Definitions of some placental hypoxic lesions have been applied relatively liberally, and many of them are frequently underreported. Objectives To present a comprehensive assessment of the criteria for diagnosing acute and chronic histologic features, patterns, and lesions of placental and fetal hypoxia and to discuss clinicopathologic associations and limitations of the use thereof. The significance of lesions that have been described relatively recently and are not yet widely used, such as laminar necrosis; excessive, extravillous trophoblasts; decidual multinucleate extravillous trophoblasts; and, most important, the patterns of diffuse chronic hypoxic preuterine, uterine, and postuterine placental injury and placental maturation defect, will be discussed.

DATA SOURCES

Literature review.

CONCLUSIONS

The placenta does not respond in a single way to hypoxia, and various placental hypoxic features should be explained within a clinical context. Because the placenta has a large reserve capacity, hypoxic lesions may not result in poor fetal condition or outcome. On the other hand, very acute, in utero, hypoxic events, followed by prompt delivery, may not be associated with placental pathology, and many poor perinatal outcomes can be explained by an etiology other than hypoxia. Nevertheless, assessment of placental hypoxic lesions is helpful for retrospective explanations of complications in pregnancy and in medicolegal investigation.