The role of placental histopathological lesions in predicting recurrence of preeclampsia

Pregnancy outcomes in correlation with placental histopathology in pregnancies complicated by fetal growth restriction with vs. without reduced fetal movements

PURPOSE

Fetal movements are crucial indicators of fetal well-being, with reduced fetal movements (RFM) suggesting potential fetal compromise. Fetal growth restriction (FGR), often linked to placental insufficiency, is a major cause of perinatal morbidity and mortality. This study aimed to investigate the neonatal, labor, and placental outcomes of FGR pregnancies with and without RFM at term.

METHODS

In this retrospective study, data from all term, singleton deliveries with FGR and concomitant RFM were obtained and compared to an equal control group of FGR without RFM. Maternal characteristics, pregnancy and neonatal outcomes, and placental histology were compared. The primary outcome was a composite of adverse neonatal outcomes. A multivariable regression analysis was performed to identify independent associations with adverse neonatal outcomes.

RESULTS

During the study period, 250 FGR neonates with concomitant RFM and an equal control group were identified. The groups did not differ in maternal demographics aside from significantly higher rates of maternal smoking in the RFM group (p < 0.001). Polyhydramnios and oligohydramnios (p = 0.032 and p = 0.007, respectively) and meconium-stained amniotic fluid (p < 0.001) were more prevalent in the FGR+RFM group. Additionally, the RFM group showed higher rates of adverse neonatal outcomes despite having larger neonates (p = 0.047 and p < 0.001, respectively). No significant differences were observed in placental findings. Logistic regression identified RFM as an independent predictor of adverse neonatal outcomes (aOR 2.45, 95% CI 1.27-4.73, p = 0.008).

CONCLUSION

Reduced fetal movements are significant and independent predictors of worse neonatal outcomes in FGR pregnancies, suggesting an additional acute insult on top of underlying placental insufficiency.

Pregnancy and placental outcomes according to maternal BMI in women with preeclampsia: a retrospective cohort study

PURPOSE

Obesity and preeclampsia share similar patho-mechanisms and can both affect placental pathology. We aimed to investigate pregnancy outcomes in correlation with placental pathology among pregnancies complicated by preeclampsia in three different maternal body mass index (BMI, kg/m2) groups.

METHODS

In this retrospective cohort study, medical and pathological records of patients with preeclampsia and a singleton pregnancy delivered between 2008 and 2021 at a single tertiary medical center were reviewed. Study population was divided into three BMI groups: BMI < 22.6 kg/m2 (low BMI group), 22.7 ≤ BMI ≤ 28.0 kg/m2 (middle-range BMI group), and BMI > 28.0 kg/m2 (high BMI group). Data regarding maternal characteristics, neonatal outcomes, and placental histopathological lesions were compared.

RESULTS

The study groups included a total of 295 patients diagnosed with preeclampsia-98, 99, and 98 in the low, middle-range, and high BMI groups respectively. Neonatal birth weight was significantly decreased in the low maternal BMI group compared to both middle and high BMI groups (p = 0.04) with a similar trend seen in placental weight (p = 0.03). Villous changes related to maternal malperfusion were more prevalent in the low and high BMI groups compared to middle-range BMI group (p < 0.01) and composite maternal vascular malperfusion lesions were also more prevalent in the groups of BMI extremities compared to the middle-range BMI group (p < 0.01).

CONCLUSION

Maternal BMI might influence neonatal outcomes and placental pathology in pregnancies complicated by preeclampsia. Both extremes of BMI were associated with higher rates of placental maternal vascular malperfusion. Balanced BMI in women at risk for preeclampsia may reduce the incidence of placental lesions.

Outcome-Based Risk Stratification Model for the Diagnosis of Placental Maternal Vascular Malperfusion

The Amsterdam Consensus Statement introduced the term maternal vascular malperfusion (MVM) to group a constellation of findings associated with impaired maternal-placental circulation. In isolation, these findings are relatively common in placentas from normal gestations, and there is uncertainty on how many, and which, are required. We aimed to determine the criteria essential for MVM diagnosis in correlation with obstetrical outcomes. A total of 200 placentas (100 with a reported diagnosis of MVM and 100 controls matched by maternal age and gravida-para-abortus status) were reviewed to document MVM features. Obstetrical outcomes in the current pregnancy were recorded including hypertension, pre-eclampsia with or without severe features, gestational diabetes, prematurity, fetal growth restriction, and intrauterine fetal demise. On univariate logistic regression analysis, adverse outcome was associated with low placental weight (LPW, <10% percentile for gestational age), accelerated villous maturation (AVM), decidual arteriopathy (DA), infarcts (presence and volume), distal villous hypoplasia, and excess multinucleated trophoblast in basal plate ≥2 mm (all P < .01) but not with retroplacental hemorrhage. In a multivariable model DA, infarcts and AVM were significantly associated with adverse outcomes, whereas LPW showed a trend toward significance. A receiver-operating characteristic curve including these 4 parameters showed good predictive ability (area under the curve [AUC], 0.8256). Based on the probability of an adverse outcome, we recommend consistent reporting of DA, AVM, infarcts, and LPW, summarizing them as "diagnostic of MVM" (DA or AVM plus any other feature, yielding a probability of 65%-97% for adverse obstetrical outcomes) or "suggestive of MVM" (if only 1 feature is present, or only 2 features are infarcts plus LPW, yielding a probability of up to 52%). Other features such as distal villous hypoplasia, excess (≥2 mm) multinucleated trophoblast, and retroplacental hemorrhage can also be reported, and their role in MVM diagnosis should be further studied.

Placental lesions attributed to shallow implantation, excess extravillous trophoblast and decidual hypoxia: Correlation with maternal vascular malperfusion and related obstetric conditions

INTRODUCTION

Maternal vascular malperfusion (MVM) is one of four main patterns of placental injury defined by the Amsterdam consensus statement and is associated with adverse fetal and maternal outcomes. Laminar decidual necrosis (DLN), extravillous trophoblast islands (ETIs), placental septa (PS), and basal plate multinucleate implantation-type trophoblasts (MNTs) are lesions attributed to decidual hypoxia, excess trophoblast, and shallow implantation, but are not included in the current MVM diagnostic criteria. We aimed to investigate the relationship between these lesions and MVM.

METHODS

A case-control model was used to evaluate for DLN, ETIs, PS, and MNTs. Placentas with MVM on pathologic examination (defined as ≥2 related lesions) constituted the case group, and maternal age- and GPA-status-matched placentas with less than 2 lesions constituted the control group. MVM-related obstetric morbidities were recorded, including hypertension, preeclampsia, and diabetes. These were correlated with the lesions of interest.

RESULTS

200 placentas were reviewed: 100 MVM cases and 100 controls. MNTs and PS showed significant enrichment in the MVM group (p < .05). Furthermore, larger foci of MNTs (>2 mm linear extent) were significantly associated with chronic or gestational hypertension (OR = 4.10; p < .05) and preeclampsia (OR = 8.14; p < .05). DLN extent correlated with placental infarction, but DLN and ETIs (including size and number) lacked association with MVM-related clinical conditions.

DISCUSSION

As a marker of abnormally shallow placentation and related maternal morbidities, MNT merits inclusion within the MVM pathologic spectrum. Consistent reporting of MNTs >2 mm in size is recommended, as these lesions correlate with other MVM lesions and MVM-predisposing morbidities. Other lesions, particularly DLN and ETI, lacked such association questioning their diagnostic utility.

Placental pathology reports: A qualitative study in a US university hospital setting on perceived clinical utility and areas for improvement

OBJECTIVE

To explore how placental pathology is currently used by clinicians and what placental information would be most useful in the immediate hours after delivery.

STUDY DESIGN

We used a qualitative study design to conduct in-depth, semi-structured interviews with obstetric and neonatal clinicians who provide delivery or postpartum care at an academic medical center in the US (n = 19). Interviews were transcribed and analyzed using descriptive content analysis.

RESULTS

Clinicians valued placental pathology information yet cited multiple barriers that prevent the consistent use of pathology. Four main themes were identified. First, the placenta is sent to pathology for consistent reasons, however, the pathology report is accessed by clinicians inconsistently due to key barriers: difficult to find in the electronic medical record, understand, and get quickly. Second, clinicians value placental pathology for explanatory capability as well as for contributions to current and future care, particularly when there is fetal growth restriction, stillbirth, or antibiotic use. Third, a rapid placental exam (specifically including placental weight, infection, infarction, and overall assessment) would be helpful in providing clinical care. Fourth, placental pathology reports that connect clinically relevant findings (similar to radiology) and that are written with plain, standardized language and that non-pathologists can more readily understand are preferred.

CONCLUSION

Placental pathology is important to clinicians that care for mothers and newborns (particularly those that are critically ill) after birth, yet many problems stand in the way of its usefulness. Hospital administrators, perinatal pathologists, and clinicians should work together to improve access to and contents of reports. Support for new methods to provide quick placenta information is warranted.

Placental pathology of preeclampsia from a clinical point of view: Correlation between placental histopathology, clinical signs of preeclampsia and neonatal outcome

AIM

To evaluate the associations between placental histopathology (signs of maternal and fetal vascular malperfusion, delayed villous maturation, villitis of unknown etiology) and subtypes of preeclampsia by onset, clinical aspects of the disease and neonatal outcome.

METHODS

Placental slides from preeclamptic pregnancies were retrospectively reviewed according to a uniform scheme. Information regarding obstetrical anamnesis, clinical data and perinatal outcome was collected from charts, and statistical analysis was performed in order to demonstrate associations between microscopic placental alterations and different aspects of preeclampsia.

RESULTS

A total of 49 cases were studied. Diffuse signs of maternal vascular malperfusion and avascular villi were more common in early-onset-preeclampsia associated with worse prognosis. Preeclampsia with fetal growth restriction had more often diffuse signs of maternal and fetal vascular malperfusion and villitis of unknown etiology. Recurring preeclampsia was associated with more common perivasculitis. Umbilical and uterine artery Doppler indices were associated with medial hypertrophy and/or acute atherosis of maternal decidual vessels. Large foci of avascular villi correlated with extent of maternal 24-h-proteinuria which itself correlated with outcome of preeclampsia. Rate of capillarisation of villi was significantly lower in case of hypertension requiring a three-drug combination of antihypertensive medications versus hypertension treated with one or two drugs, preeclampsia with growth restriction, and stillbirth versus live birth.

CONCLUSIONS

Early- versus late-onset-preeclampsia showed a markedly different profile of histopathological features and perinatal outcome, reflecting their distinguished pathogenesis and prognosis; preeclampsia complicated with fetal growth restriction also had distinctive features. Qualitative and quantitative changes define placental pathology of preeclampsia.

Practice variations for fetal and neonatal congenital heart disease within the Children's Hospitals Neonatal Consortium

BACKGROUND

Many aspects of care for fetuses and neonates with congenital heart disease (CHD) fall outside standard practice guidelines, leading to the potential for significant variation in clinical care for this vulnerable population.

METHODS

We conducted a cross-sectional survey of site sponsors of the Children's Hospitals Neonatal Consortium, a multicenter collaborative of 41 Level IV neonatal intensive care units to assess key areas of clinical practice variability for patients with fetal and neonatal CHD.

RESULTS

We received responses from 31 centers. Fetal consult services are shared by neonatology and pediatric cardiology at 70% of centers. Three centers (10%) routinely perform fetal magnetic resonance imaging (MRI) for women with pregnancies complicated by fetal CHD. Genetic testing for CHD patients is routine at 76% of centers. Preoperative brain MRI is standard practice at 5 centers (17%), while cerebral NIRS monitoring is regularly used at 14 centers (48%). Use of electroencephalogram (EEG) after major cardiac surgery is routine in 5 centers (17%). Neurodevelopmental follow-up programs are offered at 30 centers (97%).

CONCLUSIONS

Many aspects of fetal and neonatal CHD care are highly variable with evolving shared multidisciplinary models.

IMPACT

Many aspects of fetal and neonatal CHD care are highly variable. Genetic testing, placental examination, preoperative neuroimaging, and postoperative EEG monitoring carry a high yield of finding abnormalities in patients with CHD and these tests may contribute to more precise prognostication and improve care. Evidence-based standards for prenatal and postnatal CHD care may decrease inter-center variability.

Pregnancy complications and placental histology following embryo transfer with a thinner endometrium

STUDY QUESTION

Are deliveries following IVF with a thinner endometrium associated with adverse perinatal outcomes and placental findings?

SUMMARY ANSWER

Live births following IVF with a thinner endometrium are associated with an increased rate of placental-mediated obstetric complications and lower birthweight, while the placentas are notable for gross anatomical and histological malperfusion lesions.

WHAT IS KNOWN ALREADY

Past studies have noted a higher rate of adverse outcomes on deliveries following IVF with a thinner endometrium, mainly placental-associated complications. However, no study to date has investigated placental histopathology in such cases.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study of 1057 deliveries following IVF, between 2009 and 2017. All placentas were sent to pathology irrelevant of pregnancy complication status, per protocol at our institution.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Live singleton births from a tertiary university hospital after IVF were compared between patients for whom embryo transfer was performed with an endometrium <9 mm (thinner endometrium group) and patients with an endometrium ≥9 mm (control group). Placental pathologic findings were categorized according to the Amsterdam Placental Workshop Group Consensus. Outcomes were placental findings, including anatomic, inflammatory, vascular malperfusion and villous maturation lesions, as well as obstetric and perinatal outcomes. Continuous and categorical variables were compared as appropriate, and multivariate regression and linear analyses were employed to control for confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

A total 292 cases in the thinner endometrium group, and 765 in the control group were compared. Maternal demographics were non-significant between the groups, except for main fertility indication was more commonly diminished reserve in patients with a thinner endometrium and less commonly male factor, P = 0.003. Higher rates of fresh transfers were noted in the control group, while the thinner endometrium group was notable for higher rates of blastocyte transfers. After adjustment for confounders, deliveries in the thinner endometrium group were associated with an overall higher rate of main placental-mediated complications, 22.9% versus 15.2%, P = 0.003, and significantly lower birthweight, β -100.76 g (-184.4-(-17.0)). Placentas in the thinner endometrium group were notable for reduced thickness and a higher rate of bilobated placentas. Placental histology in the thinner endometrium group demonstrated a higher rate of maternal malperfusion lesions.

LIMITATIONS, REASONS FOR CAUTION

The study was limited by its retrospective design and lack of data regarding prior uterine surgery. In addition, sample size was limited for detection of differences in outcomes of rarer occurrence and for analysis as per a stricter definition of thin endometrium.

WIDER IMPLICATIONS OF THE FINDINGS

Excess obstetric risks should be taken into consideration while planning an embryo transfer with a thinner endometrium. Further studies are needed to assess the yield of cycle cancellation and the effect of potential preventive measures such as Micropirin treatment.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was used and the authors report no conflicting interests.

TRIAL REGISTRATION NUMBER

N/A.

Placental histology following assisted hatching in fresh transfer cycles

PURPOSE

To assess placental histological findings following assisted hatching in fresh transfer in vitro fertilization cycles.

METHODS

Evaluation of a historic cohort of live singleton deliveries after fresh embryo transfer (ET) at a single university medical center between 2009 and 2017. We compared perinatal outcomes and placental histology in cases where assisted hatching was performed prior to ET (AH group) and cases with no AH (no AH group).

RESULTS

Overall, 166 deliveries following AH were compared to 494 deliveries with no AH. Patients' demographics were similar between the groups. Median antral follicle count was significantly lower in the AH group, median 11 (range 1-50) vs. 16 (range 1-80), p < 0.001, and the primary indication for infertility treatment significantly more often diminished ovarian reserve (p < 0.001). Cycle characteristics in the AH group included a higher gonadotropin dose employed, and a lower rate of single and blastocyte transfer. Pregnancies following AH were associated with less low-lying placentas, 0.6% vs. 6.2%, p = 0.001, and comparable for other perinatal outcomes. After adjusting for confounders, the rate of bilobated placentas was higher following AH, aOR 7.10, 95% CI 1.50-33.51. The rate of perivillous depositions was higher with AH, aOR, 95% CI 3.18, 1.46-6.93, and the rate of chorangiosis lower in this group, aOR, 95% CI 0.32, 0.11-0.93. The overall rate of vascular lesions was similar between the groups.

CONCLUSION

Pregnancies following AH are notable for a lower rate of placenta previa, yet a higher rate of bilobated placentas and perivillous depositions and less chorangiosis, warranting further investigation.

Angiogenic factors and prediction for ischemic placental disease in future pregnancies

OBJECTIVES

Ischemic placental disease (IPD), including preeclampsia, abruption, and fetal growth restriction, often recurs in subsequent pregnancies. Angiogenic factors of placental origin have been implicated in the pathogenesis of preeclampsia, but have not been studied as predictors of IPD in subsequent pregnancies. We hypothesized that elevated angiogenic factors in an index pregnancy would be associated with recurrence of IPD.

STUDY DESIGN

We conducted a retrospective cohort study of patients undergoing evaluation for preeclampsia who had angiogenic factors measured in an index pregnancy and experienced a subsequent pregnancy at the same institution. Patients with IPD in the index pregnancy were included. A high ratio of soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF) was defined as greater than or equal to 85.

MAIN OUTCOME MEASURES

The primary outcome was IPD in a subsequent pregnancy.

RESULTS

We included 109 patients in the analysis. The sFlt1/PlGF ratio was elevated in 30% of participants. Those with an elevated ratio were more likely to be nulliparous in the index pregnancy, and less likely to have chronic hypertension. The recurrence of IPD in the study was 27%, with a non-significant difference in risk based on a high sFlt-1/P1GF ratio RR 0.58 (95% CI 0.21 - 1.6) compared to a low ratio.

CONCLUSIONS

A high sFlt1/P1GF ratio in an index pregnancy is not associated with a higher risk of IPD in a subsequent pregnancy. These data suggest placental angiogenic biomarkers are specific to the pregnancy and not a reflection of maternal predisposition to IPD.

Maternal use of selective serotonin reuptake inhibitors (SSRI) during pregnancy-neonatal outcomes in correlation with placental histopathology

OBJECTIVE

We investigated the association between prenatal selective serotonin reuptake inhibitors (SSRI) exposure and pregnancy-outcomes with correlation to placental-histopathology.

STUDY DESIGN

Included were pregnancies with maternal SSRI use throughout pregnancy (SSRI-group) and the control group was matched with pregnancies unexposed to SSRI. Placental lesions were classified according to the "Amsterdam" criteria. Adverse neonatal outcome was defined as ≥1 early neonatal-complications.

RESULTS

SSRI group had lower birthweights (p < 0.001), higher rates of meconium (p = 0.009), NICU admissions (p < 0.001), and adverse neonatal-outcome (p < 0.001). SSRI placentas had lower birthweight-to-placental-weight ratio (p = 0.02) and higher rates of fetal vascular malperfusion (FVM) lesions (p = 0.03). Using multivariable analyses: GA < 37 weeks (aOR = 2.1, 95%CI 1.7-4.6) and SSRI (aOR = 1.7, 95%CI 1.3-3.9) were independently associated with adverse neonatal outcome while GA < 37 weeks (aOR = 1.6, 95%CI 1.2-3.4), SSRI (aOR = 1.3, 95%CI 1.1-2.6), and smoking (aOR = 1.2, 95%CI 1.1-4.0) were independently associated with FVM lesions.

CONCLUSION

SSRI use during pregnancy was independently associated with adverse neonatal outcome and placental FVM.

Placental pathology in pregnancies complicated by fetal growth restriction: recurrence vs. new onset

OBJECTIVE

In an attempt to shed new light on the pathogenesis of fetal growth restriction (FGR), we aimed to study pregnancy characteristics, neonatal outcomes, and placental histopathological lesions of FGR pregnancies in two different subgroups: when developed after appropriate for gestational age (AGA) pregnancy and when developed after previous pregnancy with FGR.

STUDY DESIGN

Pregnancy and placental reports of all singleton pregnancies complicated by FGR (defined as actual birthweight below the 10th percentile according to local birthweight nomograms) between 2008 and 2018 were reviewed. Included were only cases with previous delivery. Maternal background, neonatal outcomes, and placental histopathology were compared between FGR that occurred after FGR (recurrent FGR group) and FGR that occurred after an AGA pregnancy (FGR after AGA group). Placental lesions were classified according to the current "Amsterdam" criteria. Continuous variables were compared using the Student's t test or the Mann-Whitney test as appropriate. Categorical variables were compared using Chi-square or Fisher's exact test as appropriate.

RESULTS

A total of 334 FGR cases with a previous delivery were included in the study. Of them, 111 cases constituted the recurrent FGR group and 223 constituted the FGR after AGA group. The recurrent FGR group was characterized by higher rates of maternal diabetes during pregnancy and hypertensive diseases (9% versus 2.7%, p = 0.01 and 19.8% versus 11.6%, p = 0.04). The FGR after AGA group was characterized by a higher rate of fetal vascular malperfusion (FVM) lesions (29.6% versus 18.0%, p = 0.02), and by lower mean birthweight (1842 ± 424.9 versus 1977.4 ± 412.2, p = 0.005), as compared to the recurrent FGR group.

CONCLUSION

Recurrent FGR was associated with maternal background morbidities during pregnancy which represents a chronic repeated insult, while "new" FGR cases (those followed an AGA pregnancy) were characterized by a higher rate of FVM lesions and lower birthweight which probably represent an "accident" in placentation. These findings may suggest that different mechanisms of placental dysfunction exist in the two subgroups of FGR.

Placental histopathology in IVF pregnancies resulting from the transfer of frozen-thawed embryos compared with fresh embryos

PURPOSE

To study whether placentas of singleton pregnancies conceived after fresh embryo transfer (ET) contain more histopathological lesions compared with placentas of singleton pregnancies conceived after frozen-thawed embryo transfer (FET).

METHODS

A prospective cohort study of placental histopathology in 131 women with singleton IVF pregnancies who delivered at a single medical center, between December 2017 and May 2019. The prevalence of different placental histopathology lesions was compared between women who conceived after fresh ET and FET.

RESULTS

Women who conceived after fresh ET (n = 74) did not differ from women who conceived after FET (n = 57) with regard to maternal age, BMI, nulliparity, or infertility diagnosis. Gestational week at delivery was lower in pregnancies conceived after fresh ET (38.5 vs. 39.2 weeks, respectively, p = 0.04), and a trend for a lower birthweight following fresh ET was noted (3040 vs. 3216 g, respectively, p = 0.053). However, placental histopathology analysis from pregnancies conceived after fresh ET was comparable to pregnancies conceived after FET, with regard to the prevalence of maternal vascular malperfusion lesions (45.9% vs. 50.9%, respectively, p = 0.57), fetal vascular malperfusion lesions (17.6% vs. 21.1, p = 0.61), acute inflammatory response lesions (28.4% vs. 28.1%, respectively, p = 0.96), and chronic inflammatory response lesions (13.5% vs. 8.8%, respectively, p = 0.48).

CONCLUSION

Placental histopathology did not differ between IVF pregnancies conceived after fresh and frozen ET. These results are reassuring for clinicians and patients who wish to pursue with transferring fresh embryos.

The impact of placental pathology discordance in multiple gestation pregnancies on bronchopulmonary dysplasia-associated pulmonary hypertension

Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) may either be concordant or discordant between multiple gestation births. Abnormal placental development, particularly maternal vascular malperfusion, may account for discordance in BPD-PH through fetal programming mechanisms. Maternal vascular malperfusion is a placental histologic lesion associated with intrauterine growth restriction and BPD-PH. We conducted a retrospective longitudinal cohort study of infants born <29 weeks gestation with available placental histology at Prentice Women's Hospital in Chicago from 2005-2012. The primary outcome was discordant BPD-PH associated with placental maternal vascular malperfusion. We secondarily assessed whether the risk of BPD-PH and placental lesions was different among infants of multiple (compared to singleton) gestations. The cohort consisted of 135 multiple gestation infants and 355 singletons. In a separate cohort of 39 singletons and 35 multiples, associations between 12 cytokines and angiogenic growth factors in cord blood plasma for biomarker discordance, maternal vascular malperfusion, and bronchopulmonary dysplasia were explored. Among multiples, discordant maternal vascular malperfusion was not associated with BPD-PH (OR = 1.9 (0.52, 6.9); p = 0.33) in infants exposed to placental maternal vascular malperfusion. However, singleton infants were more likely to develop BPD-PH (compared to multiples) after adjusting for mode of delivery, chorioamnionitis, chronic hypertension, placental abruption, small-for-gestational age birth weight, and gestational age (aOR = 2.7 (1.2, 5.8); p = 0.038). Singletons were more likely to be small-for-gestational age (11% vs 4%, p = 0.025) and have placental lesions compared to their multiple-gestation counterparts (96% vs 81%, p < 0.001), principally severe maternal vascular malperfusion (17% vs 4%, p < 0.001) and chronic inflammation (32% vs 11%, p < 0.001). Increased risk of BPD-PH in singleton pregnancies <29 weeks gestation compared to multiples may be related to increased frequency of these histologic lesions. Placental pathology in singleton and multiple gestation pregnancies may serve as an early biomarker to predict BPD-PH.

Placental abnormalities differ in small for gestational age neonates in relation to their prenatal sonographic abdominal circumference measurements

Background: Antenatal detection of abdominal circumference (AC) <10th percentile, among small for gestational age (SGA) neonates, probably reflects the severity of their growth restriction. We aimed to study neonatal outcome and placental pathology among SGA neonates in correlation to their AC measurements.Methods: Maternal and neonatal computerized medical records and placental histopathology reports of all SGA neonates, (neonatal birth-weight ≤10th percentile), born between 24 and 42 weeks, during 2015-2018 were reviewed. Included cases with fetal biometric measurements conducted up to 7 days prior labor. Results were compared between cases with sonographic antenatal AC <10th percentile and neonates with sonographic antenatal AC ≥10th percentile. Placental lesions were classified according to "Amsterdam" Placental workshop criteria.Results: The AC <10th percentile group (n = 148) was characterized by higher rate of nulliparity (p = .003), and induction of labor (p = .009), as compared to the AC ≥10th percentile group (n = 41). There were no between groups differences in the rate of maternal BMI (kg/m²), hypertensive disorders, diabetes or smoking. Neonatal hypoglycemia was more common in the AC <10th percentile group as compared to the AC ≥10th percentile group (p = .04). Placentas from the AC <10th percentile group were smaller (p < .001), with more MVM lesions (p = .02) and chronic villitis (p = .04). By multivariate regression analysis, AC <10th percentile and maternal hypertensive disorders, were found to be independently associated with placental MVM lesions, aOR = 2.43 (95% CI 1.04, 5.88) and aOR = 3.15 (95% CI 1.06, 9.31), respectively.Conclusions: Higher rate of placental maternal malperfusion lesions, chronic villitis, and more neonatal hypoglycemia characterize SGA neonates with AC <10th percentile, pointing to the importance of AC measurement as an indicator for placental insufficiency.

Reduced fetal movements at term in singleton low risk pregnancies-Is there an association with placental histopathological findings?

INTRODUCTION

Maternal perception of fetal movements has long been considered an indicator of fetal well-being. A sudden decrease in the number of fetal movements is suggestive of fetal compromise. We aimed to determine whether the maternal perception of reduced fetal movements (RFM) is associated with placental pathological lesions in a low-risk term population.

MATERIAL AND METHODS

Our study was a case-control study that was performed in a single university center. Placental histopathology, maternal demographics, labor characteristics, and neonatal outcomes of term, singleton pregnancies with maternal perception of RFM during the 2 weeks prior to delivery were collected. To isolate the effect of RFM on placental pathology, we excluded cases complicated by preterm birth, hypertensive disorders, diabetes mellitus, small-for-gestational-age and congenital/genetic anomalies. We compared pregnancy outcomes and placental pathology between the RFM group and a control group matched for gestational age and mode of delivery. Placental lesions were classified according to the "Amsterdam" criteria. Composite adverse neonatal outcome was defined as one or more of the following: sepsis, transfusion, hypoglycemia, phototherapy, respiratory morbidity, cerebral morbidity, necrotizing enterocolitis and fetal/neonatal death. Multivariable regression analysis was performed to identify independent associations with adverse neonatal outcome.

RESULTS

We included patients who gave birth from January 2008 until May 2019. The study group included 203 term pregnancies with RFM during the 2 weeks prior to delivery, which was matched with 203 controls. The RFM group was characterized by a higher rate of placental weight <10th percentile (22.6% vs. 3.9%, P < .001), a higher rate of maternal vascular malperfusion lesions (30.5% vs. 18.7%, P = .007) and lesions of maternal inflammatory response (43.3% vs. 29.5%, P = .005). At delivery, the RFM group had higher rates of cesarean delivery due to non-reassuring fetal heart rate monitoring (P = .01), 5-minute Apgar score ≤7 (P = .03), neonatal intensive care unit admissions (P < .001) and composite adverse neonatal outcomes (P = .007). Using multivariable analysis, RFM (adjusted odds ratio [aOR] 1.7, 95% confidence interval [CI] 1.1-4.8), and placental maternal vascular malperfusion lesions (aOR 1.2, 95% CI 1.0-2.9) were independently associated with adverse neonatal outcome.

CONCLUSIONS

After excluding important placental-related morbidities, RFM was associated with a higher rate of placental weight <10th percentile and placental maternal vascular malperfusion lesions vs. controls. This study suggests a placental involvement in the association between RFM at term and adverse pregnancy outcomes.

Pregnancy complications recur independently of maternal vascular malperfusion lesions

BACKGROUND

Spontaneous abortions, intrauterine growth restriction, and preeclampsia are thought to be caused by defective placentation and are associated with increased risk of adverse outcomes in subsequent pregnancies. However, it is not known whether the recurrence of adverse outcomes is associated with the recurrence of placental pathology. We hypothesized that recurrent maternal vascular malperfusion (MVM) underlies the recurrence of adverse outcomes.

METHODS

Using data from the National Collaborative Perinatal Project, we assessed the recurrence of pregnancy complications and MVM lesions (N = 3865), associations between a history of spontaneous abortions and MVM lesions or adverse outcomes in subsequent pregnancies (N = 8312), and whether the recurrence of pregnancy complications occurred independently of the presence of MVM lesions.

RESULTS

The odds of an MVM lesion were higher for a woman who had had an MVM lesion in a previous pregnancy (aOR = 1.6; 95% CI 1.3-1.9), although this was marginally non-significant after adjusting for covariates such as gestational age, race and BMI. The odds of preeclampsia, a small-for-gestational-age infant, premature delivery and early pregnancy loss were 2.7-5.0 times higher if there had been that same adverse outcome in a previous pregnancy. A history of spontaneous abortions was associated with higher risk of a small-for-gestational-age baby (aOR = 2.4; 95% CI 1.7-3.4) and prematurity (aOR = 5.1; 95% CI 2.3-11.5 for extremely preterm), but not preeclampsia. The recurrence of adverse outcomes was significant when restricting analyses to women without MVM lesions. Similarly, associations between adverse outcomes and previous spontaneous abortions were significant when statistically controlling for the presence of MVM lesions, or excluding pregnancies with MVM lesions.

CONCLUSIONS

Women with adverse outcomes in one pregnancy are at higher risk of complications in subsequent pregnancies. However, there is significant recurrence of adverse outcomes even in the absence of MVM.

Uncertainty over implications of placental histopathological findings: A survey of Australian and New Zealand neonatologists

AIM

Placental examination is known to provide useful information following an adverse pregnancy outcome. Despite existing literature and guidelines for placental examination; current workplace practices, attitudes towards the value of placental examination and the knowledge of perinatal clinicians regarding placental lesions of significance are unknown. The aim of the study is to explore the current knowledge of neonatologists and maternal fetal medicine specialists on placental histopathological findings and clinical management based on placental pathology.

METHODS

A total of 280 specialists working in perinatal centres across Australia and New Zealand were invited to complete a 20-question online multiple-choice-based survey addressing work-place placental examination practices, and participant beliefs regarding the utility of histopathological findings and follow-up practices.

RESULTS

A total of 74 neonatologists participated in the survey (28.2% response rate). Maternal fetal medicine specialists were excluded due to low response rate (2%). A total of 100% of respondents believed placental examination provided useful information regarding recent pregnancy and neonatal outcomes. They reported being aware of the presence of protocols for macroscopic examination of, and indications for histopathological examination of the placenta (55.4 and 54.1%, respectively). Nine neonatologists reported a system for actioning abnormal placental reports. There was no consensus amongst neonatologists as to which specific placental lesions held implications for future pregnancy or neonatal outcomes, and how these findings should be followed.

CONCLUSIONS

Our findings show placental examination is valued amongst neonatologists in Australia and New Zealand, but highlights the need for better education regarding the significance and utility of the results and what would be best practice for following up reports.

None, One, or Both Placentas Involved with Malperfusion Lesions in Twin Pregnancies Complicated by Preeclampsia-Does It Matter?

We aimed to study the association between the number of placentas with vascular malperfusion lesions in dichorionic twin pregnancies complicated by preeclampsia and the severity of the disease and pregnancy outcomes. Dichorionic twin pregnancies with preeclampsia (n = 125), from January 2007-June 2018, were reviewed. Affected placenta was defined as the presence of maternal/fetal vascular malperfusion lesions. Maternal demographics, pregnancy characteristics, and neonatal outcomes were compared between three groups: no pathological placentas, one pathological placenta, and two pathological placentas. Composite adverse neonatal outcome was defined as ≥ 1 early neonatal complication. Regression analysis models were used to recognize independent associations with the number of involved placentas. The two pathological placenta group (n = 57 pregnancies), the one pathological placenta group (n = 40 pregnancies), and the no pathological placenta group (n = 28 pregnancies) differed in terms of gestational age (GA) at delivery (p < 0.001, p = 0.008) and the rates of severe features (p = 0.028, p = 0.047). Neonates born to the two pathological placenta group (n = 114), the one pathological placenta group (n = 80), and the no pathological placenta group (n = 56) were characterized by lower birth weights (p < 0.001, p = 0.031), higher rates of small for gestational age (SGA) (p = 0.017, p = 0.748), neonatal intensive care unit admission (p = 0.004, p = 0.013), and composite adverse neonatal outcome (p < 0.001, p = 0.025). By regression analyses, the presence of two pathological placentas was found to be independently associated with severe features (aOR = 5.1), GA at delivery < 32 weeks (aOR = 2.0), SGA (aOR = 2.5), and composite adverse neonatal outcome (aOR = 2.7). In dichorionic twin pregnancies, there is an association between the presences of placental vascular malperfusion lesions in none, one, or both placentas and the development of early and severe preeclampsia, as well as with SGA and adverse neonatal outcome.

Low antithrombin activity before delivery predicts subsequent hypertensive disorders in pregnancy

OBJECTIVE

To examine whether laboratory parameters can predict the onset of recurrent hypertensive disorders of pregnancy (HDP).

METHODS

A retrospective study of 257 women with consecutive deliveries at a hospital in Sapporo, Japan, between 2009 and 2017. Women were divided into four groups according to whether or not they had HDP in the first and second peripartum periods (HDP-HPD, HDP-Non, Non-HDP, Non-Non). HDP was defined as gestational hypertension and/or proteinuria. Laboratory parameters measured on the day of or 1 day before delivery were compared between peripartum-1 and peripartum-2.

RESULTS

Frequency of HDP in peripartum-2 was higher among the 24 (9.3%) women with HPD in peripartum-1 (6/24, 25.0%) than among the 233 (90.7%) women without (3/233, 1.3%) (P<0.001). In peripartum-1, women with HDP had lower median antithrombin activity than those without (74% vs 89%, P=0.021). Antithrombin activity in peripartum-1 was also lower in the HDP-HDP (67%) than in the HDP-Non (79%) group (P=0.021). Antithrombin activities of 77% or less at the first delivery predicted HDP in peripartum-1 (P<0.001) and 70% or less predicted HDP in peripartum-2 (P=0.018).

CONCLUSION

Women with HDP in peripartum-1 had a higher incidence of HDP recurrence. Low antithrombin before a first delivery might predict recurrent HDP in a second pregnancy.

Is there a role for placental histopathology in predicting the recurrence of preterm birth?

PURPOSE

Spontaneous preterm birth (sPTB) is a major cause of neonatal morbidity and mortality with a relatively high rate to recurrence. Our aim was to study the role of placental histopathology in predicting recurrence of sPTB.

METHODS

We conducted a retrospective cohort study. The medical records and placental pathologic reports of all women with sPTB (gestational age 23^0/7-36^6/7 weeks), during 2008-2015, were reviewed. Only women who had a subsequent delivery were included. Multiple pregnancies and women with known uterine anomalies were excluded. Placental histopathology lesions were classified into maternal and fetal vascular malperfusion lesions, acute maternal and fetal inflammatory responses lesions, and chronic inflammatory lesions. Placental lesions were compared between patients with and without recurrent sPTB on their subsequent pregnancies.

RESULTS

Maternal characteristics, gestational age, birthweight, and the rate of preterm rupture of membrane at index delivery were similar between the recurrent sPTB (n = 72) and the non-recurrent sPTB (n = 167) groups. The incidence of placental vascular malperfusion lesions, or inflammatory lesions did not differ between the study groups. However, on multivariate logistic regression analysis, the presence of only acute inflammatory response lesions was associated with recurrence of early sPTB ( < 34 weeks) (adjusted OR 3.16; 95% CI 1.22-8.18).

CONCLUSION

The presence of isolated placental acute maternal or fetal inflammatory response in index sPTB may be associated with recurrence of early sPTB.

Pregnancy outcomes in correlation with placental histopathology in subsequent pregnancies complicated by fetal growth restriction

OBJECTIVE

In attempt to shed new light on the etiopathogenesis of fetal growth restriction (FGR) we aimed to compare pregnancy outcomes and placental histopathology in cases of first vs. subsequent FGR occurrence.

STUDY DESIGN

Pregnancy and placental reports of FGR pregnancies (defined by birth weight <10th percentile), born between 2008 and 2018 were reviewed. Included only cases with recurrent FGR, in two consecutive pregnancies, thus each subject served as her own control in two FGRs consecutive pregnancies. Neonatal outcome and placental histopathology were compared between the first FGR delivery (first FGR group) and the subsequent FGR delivery (subsequent FGR group). Composite adverse neonatal outcome was defined as one or more early neonatal complications.

RESULTS

Included in the study a total of 96 cases with recurrence of FGR pregnancies. Placentas from the first FGR group were characterized by higher rate of maternal vascular malperfusion (MVM) lesions as compared with the subsequent FGR group (71.8% versus 55.2%, respectively, p = 0 .02). Adverse neonatal outcome was more prevalent in the first FGR group as compared to the recurrent FGR group (41.6% versus 25%, respectively, p = 0.02). After controlling for confounders, using multivariate regression analysis, placental MVM lesions (aOR = 1.36, 95% CI = 1.12-1.45) and composite adverse neonatal outcome (aOR = 1.18 95% CI = 1.09-1.55) were found to be independently associated with the first FGR group.

CONCLUSION

First event of FGR is associated with a higher rate of placental MVM lesions and adverse neonatal outcome as compared to FGR in subsequent pregnancies.

Cesarean delivery due to nonreassuring fetal heart rate: the effect of phase of labor on subsequent vaginal delivery success

Introduction: To assess trial of labor and vaginal delivery rates in pregnancies following cesarean delivery (CD) due to nonreassuring fetal heart rate (NRFHR) according to phase of labor at cesarean.Materials and methods: This was a retrospective cohort of deliveries at a university hospital between 2009 and 2016. We compared primary CDs performed due to NRFHR during nonactive labor (cervical dilatation < 5 cm) and active labor (cervical dilatation ≥ 5 cm). Subsequent deliveries were reviewed for trial of labor and vaginal delivery rates, and maternal and obstetric outcomes compared.Results: Two hundred thirty-six patients underwent a CD during the nonactive phase of labor (nonactive phase group) and 126 patients during the active phase of labor (active phase group). Patients with a past active phase CD were more likely to attempt a trial of labor but equally likely to achieve a vaginal delivery. There was a trend for more CDs due to nonprogressive labor in this group. After adjustment, only past vaginal delivery was independently associated with a successful vaginal delivery, but not the phase of labor during which the past CD was performed.Conclusion: Our study points to a similar prognosis for patients with a past CD due to NRFHR, regardless of previous labor course.

Bloody amniotic fluid during labor - Prevalence, and association with placental abruption, neonatal morbidity, and adverse pregnancy outcomes

OBJECTIVE

To study the association between bloody amniotic fluid (BAF) during labor and adverse pregnancy outcomes.

STUDY DESIGN

In the last 10 years we have implemented an institutional protocol that mandates obstetricians/midwives to report their subjective impression of the color of amniotic fluid (clear, meconium stained, bloody) during labor. The medical records, and neonatal charts of all singleton deliveries ≥ 37^0/7 weeks between 2008-2018 were reviewed. The cohort was divided into two groups: clear AF (Clear group) and BAF (BAF group). Cases with meconium stained AF were excluded. The primary outcome was a composite of the following complications: umbilical Ph ≤ 7.1, seizures, hypoxic-ischemic encephalopathy, intra-ventricular hemorrhage, periventricular leukomalacia, hypoglycemia, hypothermia, mechanical ventilation, meconium aspiration syndrome, RDS, NEC, phototherapy, sepsis, or transfusion.

RESULTS

Overall, 21,300 deliveries were reviewed, 20,983 (98.5%) in the Clear group and 317 (1.5%) in the BAF group. The rate of the primary outcome did not differ between the BAF (2.2%) and the Clear (2.1%) groups. The rate of placental abruption (both clinically and hystopathologically) did not differ between the groups (3.2% vs. 1.9% and 1.6% vs. 0.6%, respectively). BAF was associated with higher rates of labor induction (p = 0.002), assisted vaginal deliveries (p = 0.04), cesarean deliveries (p = 0.03), and lower birth weights (p = 0.03).

CONCLUSION

BAF observed in labor was not associated with composite adverse neonatal outcome, nor with placental abruption. BAF was associated with higher rates of labor induction, assisted vaginal deliveries, cesarean deliveries, and lower birth weights. These findings may assist obstetricians and neonatologists in the interpretation of BAF observed in labor.

Placental findings in non-hypertensive term pregnancies and association with future adverse pregnancy outcomes: a cohort study

INTRODUCTION

Women with adverse pregnancy outcomes (APOs) have excess risk of later life cardiovascular disease (CVD) perhaps related to an underlying high-risk vascular phenotype. We sought to determine if placental evidence of maternal malperfusion in uncomplicated pregnancies is associated with an increased risk of APOs in subsequent pregnancies.

METHODS

536 women with more than one delivery and an initial uncomplicated pregnancy with placental pathology examination between 2008 and 2012 were included. APOs (small for gestational age, preterm delivery, or preeclampsia) were identified for each delivery. Multivariable log-binomial regression was used to estimate the risk of an APO in a subsequent pregnancy associated with MVM lesions in index pregnancy with adjustment for covariates.

RESULTS

Placental pathology from the initial pregnancy was compared between women with no APO in any pregnancy (-APO/-APO; n = 403) and women with an initial uncomplicated pregnancy and a subsequent adverse outcome (-APO/+APO; n = 133). Women with MVM lesions had an increased risk of an APO in a subsequent pregnancy relative to women with no MVM lesions after adjusting for covariates (aOR = 1.61; 95%CI = 1.06-2.46). Decidual vasculopathy was found in 13/133 (9.8%) of -APO/+APO women compared with 16/403 (4.0%) of -APO/-APO women, with an adjusted odds ratio of 2.51 (95% CI = 1.31-4.80).

DISCUSSION

MVM lesions found in placentas in uncomplicated pregnancies are associated with an increased risk of an adverse outcome in a subsequent pregnancy. Placental evidence of vascular malperfusion could offer a novel approach to risk stratification for subsequent pregnancy complications and perhaps future CVD.

Placental Peripartum Pathologies in Women with Preeclampsia and Eclampsia

Objective

To determine the pattern of pathological changes in placentas of preeclamptic/eclamptic parturients and its correlation with the clinical severity as well as the perinatal outcome.

Methods

A cross-sectional analytical study of placental pathologies in preeclamptic/eclamptic patients was performed in a blinded pattern and compared with matched normal controls. Data were analyzed using Epi-Info 2008 version 3.5.1.

Results

Placental pathologies were evaluated in 61 preeclamptic/eclamptic patients and in 122 controls. Of the 61 placentas, 53 (4.7%) were of preeclampsia while 8 (0.71%) were of eclampsia. Of the preeclamptic group, 14 (23%) had mild preeclampsia while 39 (63.9%) had severe preeclampsia. Infarction, haematoma, and some histological changes increased with the severity of preeclampsia (p < 0.001). When comparing placentas in eclampsia, severe preeclampsia, mild preeclampsia, and normal controls, there was respective increase in the presence of any infarction (75%, 66.7%, 35.7% vs. 12.3%) or any haematoma (100%, 100%, 71.4% vs. 35.2%), decidual arteriopathy (87.5%, 76.9%, 64.3% vs. 35.2%), cytotrophoblastic proliferation (75%, 71.8%, 42.9% vs. 25.4%), and accelerated villous maturation (75%, 69.2%, 57.1% vs. 31.1%). There was no statistically significant difference in placental calcifications, stromal oedema, stromal fibrosis, and syncytial knots. Degree of placental infarction was correlated with the fetal birth weight. The fetal birth weight with placental involvement of >10% was significant (p=0.01).

Conclusion

In mild or severe preeclampsia/eclampsia, placentas had significant histological signs of ischaemia and degree of placental involvement by infarction is inversely proportional to fetal birth weight. While feto-placental ratio was higher with increased severity of the disease, the mean weight was less. This trial is registered with researchregistry3503.

The frequency and type of placental histologic lesions in term pregnancies with normal outcome

Objective To determine the frequency and type of histopathologic lesions in placentas delivered by women with a normal pregnancy outcome. Methods This retrospective cohort study included placental samples from 944 women with a singleton gestation who delivered at term without obstetrical complications. Placental lesions were classified into the following four categories as defined by the Society for Pediatric Pathology and by our unit: (1) acute placental inflammation, (2) chronic placental inflammation, (3) maternal vascular malperfusion and (4) fetal vascular malperfusion. Results (1) Seventy-eight percent of the placentas had lesions consistent with inflammatory or vascular lesions; (2) acute inflammatory lesions were the most prevalent, observed in 42.3% of the placentas, but only 1.0% of the lesions were severe; (3) acute inflammatory lesions were more common in the placentas of women with labor than in those without labor; (4) chronic inflammatory lesions of the placenta were present in 29.9%; and (5) maternal and fetal vascular lesions of malperfusion were detected in 35.7% and 19.7%, respectively. Two or more lesions with maternal or fetal vascular features consistent with malperfusion (high-burden lesions) were present in 7.4% and 0.7%, respectively. Conclusion Most placentas had lesions consistent with inflammatory or vascular lesions, but severe and/or high-burden lesions were infrequent. Mild placental lesions may be interpreted either as acute changes associated with parturition or as representative of a subclinical pathological process (intra-amniotic infection or sterile intra-amniotic inflammation) that did not affect the clinical course of pregnancy.

Placental histopathological lesions in correlation with neonatal outcome in preeclampsia with and without severe features

OBJECTIVE

We aimed to compare pregnancy outcome and placental histopathology in women with preeclampsia (PE) with and without severe features.

METHODS

The medical records and placental pathology reports of all pregnancies complicated by PE during 2008-2016, were reviewed. Results were compared between those with and without severe features (severe PE vs. mild PE groups), according to current ACOG guidelines. Placental lesions were classified to maternal/fetal vascular supply lesions, and maternal/fetal inflammatory responses. Small for gestational age (SGA) was defined as neonatal birth-weight ≤10th%. Composite adverse neonatal outcome was defined as one or more of the following: sepsis, transfusion, phototherapy, respiratory morbidity, cerebral morbidity, NEC, or death.

RESULTS

The severe PE group (n = 284) was characterized by lower gestational age at delivery (p < 0.001), and higher rates of antenatal corticosteroid use (p = 0.003), and cesarean deliveries (p < 0.001) as compared to the mild PE group (n = 151). More placentas <10th% and more composite maternal vascular malperfusion (MVM) lesions were observed in the severe PE group as compared to the mild PE group (p < 0.001 for both). In multivariate analysis, composite placental MVM lesions were independently associated with severe PE (aOR = 1.75, 95%CI 1.4-4.9). Higher rates of SGA (p = 0.016), and composite adverse neonatal outcome (p = 0.002) characterized the severe PE group. In multivariate analysis, adverse neonatal outcome was independently associated with gestational age (aOR = 0.54, 95%CI 0.49-0.68), SGA (aOR = 1.75, 95%CI = 1.15-3.59), severe PE (aOR = 1.8, 95%CI = 1.13-3.54) and placental MVM lesions (aOR = 2.13, 95%CI = 1.05-4.39).

CONCLUSION

More pronounced placental pathology and higher rate of adverse neonatal outcome characterize preeclampsia with severe features as compared with the milder form of the disease.