Obstetric and perinatal complications in placentas with fetal thrombotic vasculopathy

Association of coexisting morphological umbilical cord abnormality and clinical cord compromise with hypoxic and thrombotic placental histology

To assess the usefulness and limitations of placental histology when morphological umbilical cord (UC) abnormality coexists with clinical UC compromise, 5634 consecutive placentas were divided into four groups and statistically compared: group 1-182 placentas from pregnancies with clinical features of UC compromise (variable decelerations, UC entanglement, prolapse, or true knot at delivery); group 2-1355 placentas with abnormal UC morphology or insertion; group 3-152 placentas with at least one phenotype from group 1 and one from group 2; group 4-3945 placentas with no clinical or morphological UC-related phenotypes (control group).Differences were analyzed by ANOVA or χ (2). Of 68 phenotypes studied, 13 clinical and 18 placental phenotypes were statistically significant. In group 1, 2 phenotypes were most common (oligohydramnios and abnormal fetal heart rate tracing). In group 2, 6 phenotypes were most common, including 4 clinical (abnormal umbilical artery Dopplers, nonmacerated stillbirth, multiple pregnancy, and fetal growth restriction) and 2 placental. In group 3, 23 phenotypes were most common, including 7 clinical (gestational hypertension, polyhydramnios, induction of labor, cesarean section, macerated stillbirth, congenital malformations, and abnormal 3rd stage of labor) and 16 placental. The existence of clinical signs of UC compromise alone was associated with the absence of pathomorphological placental abnormalities. However, the coexistence of clinical and abnormal morphological UC phenotypes was statistically significantly associated with placental histological signs of decreased fetal blood flow, hypoxia (acute and chronic post uterine), shallow placental implantation, and/or amnion nodosum. Thus, confirmation of clinical UC compromise should not be expected on placental examination if no morphological UC abnormality or abnormal UC insertion has been found.

MRI reveals hemodynamic changes with acute maternal hyperoxygenation in human fetuses with and without congenital heart disease

OBJECTIVE

We investigated the physiologic impact of acute maternal hyperoxygenation (MH) in human fetuses with and without congenital heart disease (CHD) using fetal cardiac magnetic resonance (CMR) in order to explore the potential therapeutic benefits of chronic MH.

METHODS

We examined 17 normal and 20 late gestation human fetuses with CHD on a 1.5 T CMR system. Flows were measured in major fetal vessels using phase contrast MRI. The T2 of umbilical venous blood was measured using T2 mapping. The measurements were repeated during acute MH. The results were compared using a Student's t-test, with p-value ≤0.05 considered statistically significant.

RESULTS

At baseline, the umbilical venous T2 (oxygen saturation) was lower in CHD fetuses than in normals, with significant increase with MH (p = 0.01). Both groups showed significant increase in pulmonary blood flow during MH, which was more dramatic in CHD (p = 0.005). There was a reduction in ductus arteriosus flow in CHD during MH (p = 0.04). There was no significant difference in blood flow in any of the other major vessels.

CONCLUSION

This study suggests that fetal MR identifies the expected hemodynamic changes associated with acute MH. MRI could be useful as a method for monitoring the impact of chronic MH in fetuses with CHD.

Fetal Thrombotic Vasculopathy: Perinatal Stroke, Growth Restriction, and Other Sequelae

Clots in the fetal circulation of the placenta may occlude or narrow the lumens of fetal vessels sufficiently to diminish the placental oxygen and nutritional exchange, causing significant reduction in placental function. When extensive, growth restriction, neonatal encephalopathy, and stillbirth may occur. Propagation of clots in other organs, such as brain, kidney, and liver, may affect the function of these organs, resulting in infarcts and neonatal stroke. This article presents an account of the placental pathology and clinical sequelae of this condition, called fetal thrombotic vasculopathy.

Correlation of preterm infant illness severity with placental histology

INTRODUCTION

A major goal of neonatal medicine is to identify neonates at highest risk for morbidity and mortality. Previously, we developed PhysiScore (Saria et al., 2010), a novel tool for preterm morbidity risk prediction. We now further define links between overall individual morbidity risk, specific neonatal morbidities, and placental pathologies.

METHODS

102 placentas, including 38 from multiple gestations, were available from the previously defined PhysiScore cohort (gestational age ≤ 34 weeks and birth weight ≤ 2000 g). Placentas were analyzed for gross and histologic variables including maternal malperfusion, amniotic fluid infection sequence, chronic inflammation, and fetal vascular obstruction. Risk as determined by PhysiScore and recorded neonatal morbidities were tested for statistical association with placental findings.

RESULTS

In pair-wise correlations, respiratory distress syndrome, bronchopulmonary dysplasia, acute hemodynamic instability, post-hemorrhagic hydrocephalus, culture-positive sepsis, and necrotizing enterocolitis each significantly correlated with at least one placenta histology variable. Amniotic fluid infection sequence (p = 0.039), specifically the fetal inflammatory response (p = 0.017), correlated with higher PhysiScores (greater morbidity) but was not independent of gestational age and birth weight. In multivariate analyses correlating variables with all nine morbidities, gestational age (p < 0.001), placental size <10th percentile (p = 0.031), full thickness perivillous fibrin deposition (p = 0.001), and amniotic fluid infection sequence (umbilical arteritis, p = 0.031; ≥2 chorionic plate vessels with vasculitis, p = 0.0125), each were significant associations.

DISCUSSION

Amniotic fluid infection sequence plays a significant role in neonatal morbidity. Less neonatal morbidity was observed in older and heavier infants and those with small placental size and full thickness perivillous fibrin deposition. The combined assessment of placental gross and histologic findings together with physiologic risk evaluation may allow more precise prediction of neonatal morbidity risk soon after delivery.

The association between umbilical cord abnormalities and the development of non-reassuring fetal heart rate leading to emergent cesarean deliveries

OBJECTIVE

To study the contribution of umbilical cord (UC) abnormalities in emergent cesarean deliveries (ECDs) for non-reassuring fetal heart rate (NRFHR) and to explore their association with placental histopathology and neonatal outcome.

STUDY DESIGN

Data from 530 ECDs for NRFHR were reviewed for the occurrence of UC abnormalities. Those included the presence of UC entanglements, the number and location of loops, true knots and short cord (<50 cm). Multiple UC entanglements were defined as ⩾ 2 UC loops. Results were compared with 530 vaginal deliveries (VD group) matched for maternal age, parity and gestational age. Additionally, we compared neonatal outcome and placental histopathology in cases of ECDs with a single vs multiple UC entanglements. Neonatal outcome consisted of low Apgar score (⩽ 7 at 5 min), cord blood pH ⩽ 7.1 and composite neonatal outcome that was defined as one or more of respiratory distress, necrotizing enterocolitis, sepsis, transfusion, ventilation, seizure, hypoxic-ischemic encephalopathy, phototherapy or death. Placental lesions were classified as: lesions related to maternal vascular supply, lesions related to fetal vascular supply (consistent with fetal thrombo-occlusive disease), and maternal and fetal inflammatory responses.

RESULTS

UC entanglements, true knots and short cords were all more common in the ECD group compared with the VD group, P<0.001, P=0.002, P=0.004, respectively. The rate of one loop entanglement did not differ between the groups. The rate of multiple UC entanglements was higher in the ECD group compared with the VD group, 20.6% vs 6.4%, respectively, P<0.001. ECDs with multiple compared with single UC entanglement had higher rate of adverse neonatal outcome, P=0.031, and more placental fetal vascular lesions 19.3% vs 8.1%, P=0.027, respectively.

CONCLUSION

Multiple UC entanglements, true knots and short cords were more common in ECDs for NRFHR, suggesting their role in the development of fetal placental vascular lesions and adverse neonatal outcome.

3-D volumetric MRI evaluation of the placenta in fetuses with complex congenital heart disease

INTRODUCTION

Placental insufficiency remains a common cause of perinatal mortality and neurodevelopmental morbidity. Congenital heart disease (CHD) in the fetus and its relationship to placental function is unknown. This study explores placental health and its relationship to neonatal outcomes by comparing placental volumes in healthy pregnancies and pregnancies complicated by CHD using in vivo three-dimensional MRI studies.

METHODS

In a prospective observational study, pregnant women greater than 18 weeks gestation with normal pregnancies or pregnancies complicated by CHD were recruited and underwent fetal MR imaging. The placenta was manually outlined and the volume was calculated in cm(3). Brain volume was also calculated and clinical data were also collected. Relationships, including interactive effects, between placental and fetal growth, including brain growth, were evaluated using longitudinal multiple linear regression analysis.

RESULTS

135 women underwent fetal MRI between 18 and 39 weeks gestation (mean 31.6 ± 4.4). Placental volume increased exponentially with gestational age (p = 0.041). Placental volume was positively associated with birth weight (p < 0.001) and increased more steeply with birth weight in CHD-affected fetuses (p = 0.046). Total brain and cerebral volumes were smaller in the CHD group (p < 0.001), but brainstem volume (p < 0.001) was larger. Placental volumes were not associated with brain volumes.

DISCUSSION

Impaired placental growth in CHD is associated with gestational age and birth weight at delivery. Abnormalities in placental development may contribute to the significant morbidity in this high-risk population. Assessment of placental volume by MRI allows for in vivo assessments of placental development.

Stillbirth: Genome-wide copy number variation profiling in archived placental umbilical cord samples with pathologic and clinical correlation

INTRODUCTION

Stillbirth remains a devastating health issue with 26,000 stillbirths occurring annually in the United States. Formalin-fixed, paraffin-embedded (FFPE) umbilical cord samples are available for many stillbirths. Our aim was to validate the use of these samples in identifying genetic variations in stillbirth through microarray analysis.

METHODS

This is a retrospective case-control study from a single institution of stillbirths ≥ 23 weeks gestational age and control liveborn infants. Fetal genomic DNA was extracted from FFPE umbilical cord samples of stillborn and control placentas, and genotyping was performed using the Illumina HumanOmniExpresss-12v1 Beadchip. Array results were verified with qPCR.

RESULTS

31 case-specific CNVs (17 deletions and 14 amplifications) with an average size of 294 kb for amplifications and 74 kb for deletions were identified among 94 FFPE samples (86 cases; 8 controls). In total 38 (44%) of the stillbirth samples had a CNV detected. Validation of a subset of microarray findings with qPCR confirmed deletions on 1p (2 cases), 11q (4 cases) and amplifications on 18 (1 case). Placental underperfusion changes were seen in stillborns with deletions on 1p, a region containing complement regulatory genes which have been shown to play a role in preeclampsia.

DISCUSSION

This study validated the use of archived FFPE umbilical cord samples for genome-wide copy number profiling in stillbirths, and demonstrates specific CNV deletions and amplifications. Microarray analysis in an expanded cohort of stillbirth FFPE samples has the potential to identify biomarkers involved in stillbirth pathogenesis.

IFPA Gábor Than Award Lecture: Recognition of placental failure is key to saving babies' lives

In high-income countries, placental failure is implicated in up to 65% of cases of stillbirth. Placental failure describes the situation where the placenta cannot meet the fetus' needs and may be the end-result of a variety of underlying pathological processes evident in the placental disc, membranes and umbilical cord. These include lesions with genetic, environmental, infectious, inflammatory, mechanical, metabolic, traumatic or vascular origin. Investigation of placental tissue from stillbirths and from pregnancies at an increased risk of stillbirth has demonstrated changes in macroscopic and microscopic structure which are themselves related to abnormal placental function. A better understanding and identification of placental failure may improve the management of pregnancy complications and of pregnancies after stillbirth (which have a 5-fold increased risk of stillbirth). The majority of current antenatal tests focus on the fetus and its response to the intrauterine environment; few of these investigations reduce stillbirths in low-risk pregnancies. However, some currently used investigations reflect placental development, structure and vascular function, while other investigations employed in clinical research settings such as the evaluation of placental structure and shape have a good predictive value for adverse fetal outcome. In addition, recent studies suggest that biomarkers of placental inflammation and deteriorating placental function can be detected in maternal blood suggesting that holistic evaluation of placental structure and function is possible. We anticipate that development of reliable tests of placental structure and function, coupled to assessment of fetal wellbeing offer a new opportunity to identify pregnancies at risk of stillbirth and to direct novel therapeutic strategies to prevent it.

Placental lesions associated with oligohydramnios in fetal growth restricted (FGR) pregnancies

INTRODUCTION

Aim of the study was to investigate the association between placental pathology and oligohydramnios in pregnancies complicated by fetal growth restriction (FGR).

METHODS

Placentas from 221 consecutive FGR pregnancies and 63 healthy controls were studied. Pathological lesions were described according to consensus nomenclature and standardized criteria; both elementary lesions and constellations of lesions (patterns) were considered. Statistics included analysis of linear trends and multinomial logistic regression.

RESULTS

Amniotic fluid index (AFI) was normal in 56 (25.3%) FGR pregnancies, whereas mild, moderate and severe oligohydramnios were diagnosed in 32 (14.5%), 44 (19.9%) and 89 (40.3%) subjects, respectively. In FGR pregnancies, after adjustment for potential confounders, membrane meconium staining (chi-square = 28.6, p < 0.001), chronic villous hypoxia pattern (chi-square = 18.8, p < 0.001) and fetal thrombotic vasculopathy pattern (chi-square = 9.2, p = 0.002) were positively and linearly correlated to AFI decrease. Odds ratios of meconium and chronic villous hypoxia were 9.2 (95% CI = 2.6-32.9) and 4.2 (95% CI = 1.3-13.6) in FGR pregnancies with normal AFI and 25.2 (95% CI = 6.9-91.8) and 9.7 (95% CI = 3-31.5) in those with severe oligohydramnios (p = 0.005 and p = 0.023 compared to normal AFI, respectively).

DISCUSSION

In FGR pregnancies, reduction of amniotic fluid volume is directly correlated to histological features of placental under-perfusion, meconium staining of membranes and fetal vascular damage. These findings support the clinical notion that in FGR pregnancies oligohydramnios is a risk factor of fetal hypoxia and possibly of increased adverse neonatal outcomes.

The clinical implications of placental diagnoses

The clinical utility of placental pathology is both overestimated and underestimated, and the overall quality of placental pathology reporting, even at major medical centers, is highly variable. Clear benefits of examining placentas include the immediate diagnosis of treatable conditions in both the mother and the infant, clarification of the underlying etiology of adverse pregnancy outcomes, estimation of recurrence risk, and guidance for the management of future pregnancies. In order to realize these benefits and get the most out of their pathology departments, it is critical for clinicians to understand the range and implications of placental lesions. This article will review the nomenclature, diagnostic criteria and pitfalls, and clinical significance of seven common placental disease processes and a handful of other lesions.

Placental lesions associated with acute atherosis

OBJECTIVE

Acute atherosis is a lesion of the spiral arteries characterized by fibrinoid necrosis of the vessel wall, an accumulation of fat-containing macrophages, and a mononuclear perivascular infiltrate, which can be found in patients with preeclampsia, fetal death, small-for-gestational age, spontaneous preterm labor/premature prelabor rupture of membrane, and spontaneous mid-trimester abortion. This lesion is thought to decrease blood flow to the intervillous space which may lead to other vascular lesions of the placenta. The objective of this study was to test whether there is an association between acute atherosis and placental lesions that are consistent with maternal vascular underperfusion (MVU), amniotic fluid infection (AFI), fetal vascular thrombo-occlusive disease (FVTOD) or chronic inflammation.

MATERIAL AND METHODS

A retrospective cohort study of pregnant women who delivered between July 1998 and July 2014 at Hutzel Women's Hospital/Detroit Medical Center was conducted examine 16 457 placentas. The frequency of placenta lesions (diagnosed using the criteria of the Perinatal Section of the Society for Pediatric Pathology) was compared between pregnancies with and without acute atherosis.

RESULTS

Among 16 457 women who were enrolled, 10.2% (1671/16 457) were excluded, leaving 14 786 women who contributed data for analysis. Among them, the prevalence of acute atherosis was 2.2% (326/14 786). Women with acute atherosis were more than six times as likely as those without to have placental lesions consistent with maternal underperfusion (adjusted odds ratio - aOR: 6.7; 95% CI 5.2-8.6). To a lesser degree, acute atherosis was also associated with greater risks of having either lesions consistent with FVTOD (aOR 1.7; 95% CI 1.2-2.3) or chronic chorioamnionitis (aOR 1.9; 95% CI 1.3-3), but not with other chronic inflammatory lesions, after adjusting for gestational age at delivery. In contrast, women with acute atherosis were 60% less likely to have lesions consistent with AFI, adjusting for gestational age at delivery (aOR 0.4; 95% CI 0.3-0.5).

CONCLUSIONS

Acute atherosis is associated with increased risks of having placental lesions consistent with MVU, and to a lesser extent, chronic chorioamnionitis and those consistent with FVTOD.

Fetal thrombotic vasculopathy is associated with thromboembolic events and adverse perinatal outcome but not with neurologic complications: a retrospective cohort study of 54 cases with a 3-year follow-up of children

OBJECTIVE

to test the hypothesis that placental fetal thrombotic vasculopathy (FTV) is associated with obstetric complications and predisposes the child to unfavorable outcomes.

METHODS

54 placentas with FTV lesions and 100 placentas without FTV lesions were collected over a 5-year period at the Croix-Rousse Pathology Department. Clinical findings including maternal, fetal, neonatal condition and pediatric outcome up to three years were collected for each case and control observation. The statistical analyses were assessed with Wald's chi-square derived from conditional logistic regression modeling.

RESULTS

FTV was associated with a significantly higher frequency of obstetric complications: (pregnancy-induced hypertension (OR 3.620, CI 1.563-8.385), preeclampsia (OR 3.674, CI 1.500-8.998), emergency delivery procedures (OR 3.727, CI 1.477-9.403), cesarean sections (OR 2.684, CI 1.016-7.088)), poor fetal condition (intrauterine growth restriction (IUGR) (OR 5.440, CI 2.007-14.748), nonreassuring fetal heart tracing (OR 6.062, CI 2.280-16.115), difficulties in immediate ex utero adaptation (OR 3.416, CI 1.087-10.732)) and perinatal or early childhood demise (OR 3.043, CI 1.327-6.978). On pathological examination, FTV was associated with marginal cord insertion (OR 3.492, CI 1.350-9.035), cord stricture and hypercoiled cord (OR 3.936, CI 1.209-12.813). Thromboembolic events were significantly more frequent in cases with FTV (OR 2.154, CI 1.032-5.622). Neurological complications within the first 3 years of life were also more frequent in the FTV group compared to the control group, but this association was not statistically significant.

CONCLUSIONS

FTV is associated with maternal complications, pathological findings in the placenta, especially gross cord abnormalities, IUGR, and poor perinatal or early childhood outcome. It may also predispose children to somatic thromboembolic events.

Placental pathology, perinatal death, neonatal outcome, and neurological development: a systematic review

BACKGROUND

The placenta plays a crucial role during pregnancy for growth and development of the fetus. Less than optimal placental performance may result in morbidity or even mortality of both mother and fetus. Awareness among pediatricians, however, of the benefit of placental findings for neonatal care, is limited.

OBJECTIVES

To provide a systematic overview of the relation between placental lesions and neonatal outcome.

DATA SOURCES

Pubmed database, reference lists of selected publications and important research groups in the field.

STUDY APPRAISAL AND SYNTHESIS METHODS

We systematically searched the Pubmed database for literature on the relation between placental lesions and fetal and neonatal mortality, neonatal morbidity and neurological outcome. We conducted three separate searches starting with a search for placental pathology and fetal and neonatal mortality, followed by placental pathology and neonatal morbidity, and finally placental pathology and neurological development. We limited our search to full-text articles published in English from January 1995 to October 2013. We refined our search results by selecting the appropriate articles from the ones found during the initial searches. The first selection was based on the title, the second on the abstract, and the third on the full article. The quality of the selected articles was determined by using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Placental lesions are one of the main causes of fetal death, where placental lesions consistent with maternal vascular underperfusion are most important. Several neonatal problems are also associated with placental lesions, whereby ascending intrauterine infection (with a fetal component) and fetal thrombotic vasculopathy constitute the greatest problem.

CONCLUSIONS

The placenta plays a key role in fetal and neonatal mortality, morbidity, and outcome. Pediatricians should make an effort to obtain the results of placental examinations.

Placental pathology and neurological morbidity in preterm infants during the first two weeks after birth

BACKGROUND

The placenta plays a crucial role during pregnancy and dysfunction causes long-term neurological problems. Identifying placenta-related risks for neurological problems shortly after birth may provide clues for early interventions aiming to improve neurological outcome.

OBJECTIVE

To determine the association between placental pathology and neurological morbidity in preterm infants during the first two weeks after birth.

STUDY DESIGN

Placentas of 52 singleton, preterm infants (GA: 25-31weeks, BW: 560-2250 grammes) were examined for histopathology. The infants' neurological condition shortly after birth was determined by assessing the quality of their general movements (GMs): normal, abnormal, or hypokinetic, on days 5, 8, and 15. A motor optimality score (MOS) was also assigned.

RESULTS

Examination of the placentas revealed maternal vascular underperfusion (n=29), ascending intrauterine infection (AIUI) (n=19), villitis of unknown aetiology (n=6), chronic deciduitis (n=11), foetal thrombotic vasculopathy (FTV) (n=9), and elevated nucleated red blood cells (NRBCs) as a marker for foetal hypoxia (n=7). None of the placental lesions were significantly associated with the quality of GMs or MOS.

CONCLUSIONS

This study indicated that placental lesions were not associated with infants' neurological condition as measured by the quality of their general movements during the first two weeks after birth.

Placental pathology in full-term infants with hypoxic-ischemic neonatal encephalopathy and association with magnetic resonance imaging pattern of brain injury

OBJECTIVE

To investigate the relationship between placental pathology and pattern of brain injury in full-term infants with neonatal encephalopathy after a presumed hypoxic-ischemic insult.

STUDY DESIGN

The study group comprised full-term infants with neonatal encephalopathy subsequent to presumed hypoxia-ischemia with available placenta for analysis who underwent cerebral magnetic resonance imaging (MRI) within the first 15 days after birth. Macroscopic and microscopic characteristics of the placenta were assessed. The infants were classified according to the predominant pattern of brain injury detected on MRI: no injury, predominant white matter/watershed injury, predominant basal ganglia and thalami (BGT) injury, or white matter/watershed injury with BGT involvement. Maternal and perinatal clinical factors were recorded.

RESULTS

Placental tissue was available for analysis in 95 of 171 infants evaluated (56%). Among these 95 infants, 34 had no cerebral abnormalities on MRI, 27 had white matter/watershed injury, 18 had BGT injury, and 16 had white matter/watershed injury with BGT involvement. Chorioamnionitis was a common placental finding in both the infants without injury (59%) and those with white matter/BGT injury (56%). On multinomial logistic regression analysis, white matter/watershed injury with and without BGT involvement was associated with decreased placental maturation. Hypoglycemia was associated with an increased risk of the white matter/BGT injury pattern (OR,5.4; 95% CI, 1.4-21.4). The BGT injury pattern was associated with chronic villitis (OR, 12.7; 95% CI, 2.4-68.7). A placental weight <10th percentile appeared to be protective against brain injury, especially for the BGT pattern (OR, 0.1; 95% CI, 0.01-0.7).

CONCLUSION

Placental weight <10th percentile was mainly associated with normal cerebral MRI findings. Decreased placental maturation and hypoglycemia <2.0 mmol/L were associated with increased risk of white matter/watershed injury with or without BGT involvement. Chronic villitis was associated with BGT injury irrespective of white matter injury.

Intrauterine growth restriction associated with excessively long umbilical cord

We present a 37-week female baby, known with intrauterine growth restriction since 25 weeks of pregnancy, born with a placenta with an excessive long umbilical cord (ELUC), without any other abnormalities. ELUC is mostly an incidental finding after delivery, but represents a potentially detectable intrauterine cause of growth restriction. A system that allows ultrasound measurement of the length of the umbilical cord could highly increase antenatal diagnosis of ELUC.

Placental histologic criteria for diagnosis of cord accident: sensitivity and specificity

"Cord accident" (compromised umbilical blood flow) as a cause of stillbirth is underreported, mainly due to a lack of diagnostic criteria. Based on fetal vascular pathology in the placenta, we have previously established histologic criteria for the diagnosis of cord accident. In the current study, we set out to test the sensitivity and specificity of these criteria by reviewing an independent set of stillbirth cases. Placental slides from 26 cases (in which cord accident was deemed the cause of death) and 62 controls (in which the cause of death was anything other than cord accident) were reviewed. The following histologic changes were noted: (1) dilated fetal vessels, (2) thrombosis in fetal vessels, and (3) avascular or near-avascular chorionic villi. "Minimal" criteria were defined as the presence of dilated and thrombosed fetal vessels, while the additional presence of focal or regional avascular or near-avascular villi satisfied the complete criteria. Of the 62 stillbirth controls with cause of death other than cord accident, 13 (21%) met the minimal criteria (specificity 79%) and only 4 (6%) met the complete criteria for cord accident (specificity 94%). In contrast, of the 26 cases with a cause of death related to cord accident, 16 met the minimal criteria (sensitivity 62%) and 12 met the complete criteria (sensitivity 46%). These histologic criteria identify cases of cord accident as a cause of stillbirth with very high specificity. This study confirms the utility of these criteria for diagnosis of cord accident and further stresses placental examination in evaluation of stillbirths.

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

OBJECTIVE

To identify by an inductive statistical analysis mutually similar and clinically relevant clinicoplacental clusters.

STUDY DESIGN

Twenty-nine maternofetal and 49 placental variables have been retrospectively analyzed in a 3382 case clinicoplacental database using a hierarchical agglomerative Ward dendrogram and multidimensional scaling.

RESULTS

The exploratory cluster analysis identified 9 clinicoplacental (macerated stillbirth, fetal growth restriction, placenta creta, acute fetal distress, uterine hypoxia, severe ascending infection, placental abruption, and mixed etiology [2 clusters]), 5 purely placental (regressive placental changes, excessive extravillous trophoblasts, placental hydrops, fetal thrombotic vasculopathy, stem obliterative endarteritis), and 1 purely clinical (fetal congenital malformations) statistically significant clusters/subclusters. The clusters of such variables like clinical umbilical cord compromise, preuterine and postuterine hypoxia, gross umbilical cord or gross chorionic disk abnormalities did not reveal statistically significant stability.

CONCLUSION

Although clinical usefulness of several well-established placental lesions has been confirmed, claims about high predictability of others have not.

Antenatal antecedents of cognitive impairment at 24 months in extremely low gestational age newborns

BACKGROUND AND OBJECTIVES

Extremely low gestational age neonates are more likely than term infants to develop cognitive impairment. Few studies have addressed antenatal risk factors of this condition. We identified antenatal antecedents of cognitive impairment determined by the Mental Development Index (MDI) portion of the Bayley Scales of Infant Development, Second Edition (BSID-II), at 24 months corrected age.

METHODS

We studied a multicenter cohort of 921 infants born before 28 weeks of gestation during 2002 to 2004 and assessed their placentas for histologic characteristics and microorganisms. The mother was interviewed and her medical record was reviewed. At 24 months adjusted age, children were assessed with BSID-II. Multinomial logistic models were used to estimate odds ratios.

RESULTS

A total of 103 infants (11%) had an MDI <55, and 99 infants (11%) had an MDI between 55 and 69. No associations were identified between organisms recovered from the placenta and developmental delay. Factors most strongly associated with MDI <55 were thrombosis of fetal vessels (OR 3.1; 95% confidence interval [CI] 1.2, 7.7), maternal BMI >30 (OR 2.0; 95% CI 1.1, 3.5), maternal education ≤12 years (OR 3.4; 95% CI 1.9, 6.2), nonwhite race (OR 2.2; 95% CI 1.3, 3.8), birth weight z score < -2 (OR 2.8; 95% CI 1.1, 6.9), and male gender (OR 2.7; 95% CI 1.6, 4.5).

CONCLUSIONS

Antenatal factors, including thrombosis of fetal vessels in the placenta, severe fetal growth restriction, and maternal obesity, convey information about the risk of cognitive impairment among extremely premature newborns.

Placental pathology is associated with illness severity in preterm infants in the first twenty-four hours after birth

BACKGROUND

Placental pathology is associated with long-term neurological morbidity. Little is known about the association of placental pathology and illness severity directly after birth in preterm infants.

OBJECTIVE

To determine the association between placental pathology and illness severity in preterm infants during the first 24 h after birth.

STUDY DESIGN

Placentas of 40 preterm infants, born after singleton pregnancies (gestational age 25.4-31.7 weeks, birth weight 560-2250 g) were assessed for histopathology. Illness severity was measured using the Score of Neonatal Acute Physiology Perinatal Extension (SNAPPE). A high SNAPPE reflects high illness severity.

RESULTS

Examination of the 40 placentas revealed: pathology consistent with maternal vascular underperfusion (MVU) (n=24), ascending intrauterine infection (AIUI) (n=17), villitis of unknown aetiology (VUE) (n=6), foetal thrombotic vasculopathy (FTV) (n=6), elevated nucleated red blood cells (NRBCs) (n=6), and chronic deciduitis (n=10). SNAPPE ranged from 1 to 53 (median 10). Infants with elevated NRBCs had a higher SNAPPE than infants without elevated NRBCs (median 30 vs. 10, p=0.014). The same was found for the presence of FTV (median 30 vs. 10, p=0.019). No relation existed between SNAPPE and the other placental pathologies.

CONCLUSIONS

Elevated NRBCs and FTV were associated with higher illness severity during the first 24 h after birth in preterm infants. Ascending intrauterine infection was not associated with high illness severity.