Fetal growth at term and placental oxidative stress in a tissue micro-array model: a histological and immunohistochemistry study

This study examines 8-hydroxyguanine (8-oxo-Gua) staining in placental tissue samples based on fetal size at birth as well as its relationships with placental histology and other pregnancy variables. This prospective cohort study included women > 18 years with a singleton pregnancy, a live fetus, fluency in Italian, and delivery at term. A total of 165 pregnancies were included in the study. The nuclear syncytiotrophoblast 8-oxo-Gua staining score in LGA was substantially greater than in late FGR (p < 0.05), although the cytoplasm score was lower in SGA and LGA than in AGA (p < 0.05). Furthermore, a sex-specific pattern of 8-oxo-Gua staining was discovered in single-term placentas, with more oxidative damage found in the nuclei of syncytiotrophoblast cells and stromal and endothelial cells in AGA males compared to AGA females (p < 0.05). Second, the histological pattern of late FGR placentae differed by gender. Finally, a significant correlation (p < 0.05) was found between high-intensity 8-oxo-Gua staining in the cytoplasm of syncytiotrophoblast cells and thrombi in the chorionic plate or villi in males. On the other hand, female fetuses demonstrated a significant connection (p < 0.05) between high-intensity 8-oxo-Gua staining in endothelial and stromal cells and high birthweight MoM values. Our findings indicated a significant variation in the oxidative stress pattern between male and female placentae, implying that fetal growth is regulated differently in the two sexes.

Spontaneous preterm birth with placental maternal vascular malperfusion is associated with cardiovascular risk in the fifth decade of life

Women with a history of spontaneous preterm birth (SPTB) have a mildly elevated cardiovascular risk (CVR) later in life and women with a history of preeclampsia have a highly elevated CVR. In placentas of women with preeclampsia pathological signs of maternal vascular malperfusion (MVM) are often seen. These signs of MVM are also seen in a substantial part of the placentas of women with SPTB. We therefore hypothesize that in women with a history of SPTB, the subgroup with placental MVM has an elevated CVR. This study is a secondary analysis of a cohort study including women 9-16 years after a SPTB. Women with pregnancy complications known to be associated with CVR were excluded. The primary outcome was hypertension defined as blood pressure ≥ 130/80 mmHg and/or treatment with antihypertensive medication. Secondary outcomes were mean blood pressure, anthropometrics, blood measurements including cholesterol and HbA1c, and creatinine in urine. Placental histology was available in 210 (60.0%) women. MVM was found in 91 (43.3%) of the placentas, most often diagnosed by the presence of accelerated villous maturation. Hypertension was diagnosed in 44 (48.4%) women with MVM and in 42 (35.3%) women without MVM (aOR 1.76, 95% CI 0.98 - 3.16). Women with a SPTB and placental MVM showed significantly higher mean diastolic blood pressure, mean arterial pressure and HbA1c approximately 13 years after delivery, compared to women with a SPTB without placental MVM. We therefore conclude that placental malperfusion in women with a SPTB might differentiate in CVR later in life.

Association of Placental Histology with the Pulsatility Index of Fetal and Uteroplacental Vessels during Pregnancy and with Birthweight Z-Score

Aims

To compare macro- and microscopic features of the placenta with the pulsatility index (PI) of the uterine (UtA), umbilical (UA) and middle cerebral arteries at 20-24- and 34-38-weeks' gestation, and with birthweight z-scores (BWZS).

Methods

Recruitment for the Safe Passage Study, which investigated the association of alcohol and tobacco use with stillbirth and sudden infant death syndrome, occurred from August 2007 to January 2015 at community clinics in Cape Town, South Africa. The population represents a predominantly homogenous population of pregnant women from a low socioeconomic residential area. This study is a further analysis of the data of the Safe Passage Study. It consists of 1205 singleton pregnancies for which placental histology was available, of whom 1035 had a known BWZS and 1022 and 979 had fetoplacental Doppler examinations performed at Tygerberg Academic Hospital at 20-24 and 34-38 weeks respectively. Features of the placenta were assessed according to international norms.

Results

Significantly higher ORs for the presence of individual and combined features of maternal vascular malperfusion (MVM) were found with lower BWZS and higher UtA PI values, more consistently than with higher UA PI values. Strongest associations were for a small placenta for gestational age (UtA OR 4.86 at 20-24 and 5.92 at 34-38 weeks; UA OR 5.33 at 20-24 and 27.01 at 34-38 weeks; low BWZS OR 0.31), for accelerated maturation (UtA OR 11.68 at 20-24 weeks and 18.46 at 34-38 weeks; low BWZS 0.61), for macroscopic infarction (UtA OR 6.08 at 20-24 weeks; UA OR 17.02 at 34-38 weeks; low BWZS OR 0.62) and for microscopic infarction (UtA OR 6.84 at 20-24 and 10.9 at 34-38 weeks; low BWZS OR 0.62).

Conclusion

There is considerable variability in the associations between individual features of MVM and increased UtA or UA PI and low BWZS. Although all MVM features currently carry equal weight in defining the condition of MVM, our data suggest that some should carry more weight than others. Macroscopic examination of the placenta may be helpful in identifying placental insufficiency as a small placenta for gestational age and macroscopic infarction were the features most strongly associated with outcomes.

Histopathologic evaluation of dichorionic twin placentas in unassisted and in vitro fertilized pregnancies affected by preeclampsia

OBJECTIVE

Pregnancies achieved with assisted reproductive technology have an increased risk of multiple gestations, preeclampsia, and placental morphologic abnormalities. Inflammatory processes affect dichorionic twin pregnancies disproportionately more than singleton gestations and have been associated with adverse pregnancy outcomes, such as fetal growth restriction and preeclampsia. Our objective is to investigate the placental morphology of dichorionic twin pregnancies complicated by preeclampsia conceived with in vitro fertilization (IVF) versus unassisted.

METHODS

This is a retrospective analysis of placentas from dichorionic twin pregnancies affected by preeclampsia conceived with IVF versus without assistance from 2010 to 2016 at a tertiary care university hospital. Placental pathology findings were analyzed both independently and in aggregate stratified into composite outcome scores using a modified placental synoptic framework. Individual placental abnormalities were grouped into composite categories based on the site of origin: anatomic placental abnormalities; maternal vascular malperfusion; placental villous maldevelopment; fetal vascular malperfusion; chronic utero-placental separation; maternal-fetal interface disturbance; inflammation of infectious etiology; and inflammation of idiopathic etiology. Placental histopathological statistical analysis was performed using Fisher's exact test. Demographic variables and pregnancy outcomes were compared between groups using the Student's t test or Mann-Whitney U test, where appropriate. p < .05 defined statistical significance.

RESULTS

Of 117 dichorionic twin pregnancies, 60 resulted from IVF (Group A) and 57 were conceived without assistance (Group B). Patients in Group A were older (36 [29-37] vs. 33 [32-38] respectively; p = .042) and less parous (18.3% vs. 38.6% percent parous in Group A and Group B, respectively p = .009) than Group B, respectively. No differences were found between groups regarding mode of delivery, gestational age at delivery, placental weight/birthweight, fetal growth restriction, and discordance of fetal growth. There were significantly more inflammatory changes of unknown etiology and composite inflammatory abnormalities in Group A versus Group B (26.7% vs. 10.5%, p = .02). The cumulative number of inflammatory abnormalities per patient had a significantly different distribution among groups (p = .005), and Composite Chronic Inflammation and Infection were found to be significantly more abundant in Group A versus Group B (p = .02). The distribution of placental composite anatomic placental abnormalities, maternal vascular malperfusion, placental villous maldevelopment, fetal vascular malperfusion, chronic utero-placental separation, or maternal-fetal interface disturbance was not statistically different between groups. The distribution of placental abnormalities was not different between groups for any individually analyzed pathological condition. Due to the relatively small sample size, adjustment for potential confounders was not performed.

CONCLUSION

Dichorionic twin pregnancies affected by preeclampsia are associated with more placental inflammatory abnormalities if conceived with IVF versus unassisted. Further research is needed to ascertain the underlying mechanisms of these observed differences.

The key role of examining the placenta in establishing a probable cause for stillbirth

INTRODUCTION

Autopsy is regarded as the "gold standard" to determine probable causes of stillbirths. However, autopsy is expensive and not readily available in low- and middle-income countries. Therefore, we assessed how the clinical cause of death is modified by adding placental histology and autopsy findings.

METHOD

Data from the Safe Passage Study was used where 7060 pregnant women were followed prospectively. Following a stillbirth, each case was discussed and classified at weekly perinatal mortality meetings. This classification was later adapted to the WHO ICD PM system. Clinical information was presented first, and a possible cause of death decided upon and noted. The placental histology was then presented and, again, a possible cause of death, using the placental and clinical information, was decided upon and noted, followed by autopsy information. Diagnoses were then compared to determine how often the additional information changed the initial clinical findings.

RESULTS

Clinical information, placental histology, and autopsy results were available in 47 stillbirths. There were major amendments from the clinical only diagnoses when placental histology was added. Forty cases were classified as due to M1: complications of placenta, cord, and membranes, when placental histology was added compared to 7 cases with clinical classification only, and M5: No maternal condition identified decreased from 30 cases to 3 cases. Autopsy findings confirmed the clinical and placental histology findings.

DISCUSSION

Clinical information together with examination of the placenta revealed sufficient information to diagnose the most probable cause of death in 40 of 47 cases of stillbirth (85%).

Association of late second trimester miscarriages with placental histology and autopsy findings

OBJECTIVES

To describe the placental histology and autopsy findings in pregnancies where fetal demise occurred before a gestational age of 22 weeks.

STUDY DESIGN

This study was a subset of a larger study where the effect of alcohol exposure during pregnancy on stillbirths was studied. In a prospective cohort, 7,010 singleton pregnancies were followed from the first antenatal visit until infant one year of age visit. Gestational age was assessed by ultrasound, preferably at the first antenatal visit. All pregnancy losses were identified and when the fetuses delivered at or after a gestation of 20 weeks, the mother or parents were approached for consent for autopsy. This study describes the placental pathology and findings at autopsy in losses before 22 weeks gestation (late second trimester miscarriages).

RESULTS

Fourteen cases were identified in which 13 had an autopsy and 12 had a histological examination of the placenta. The most prevalent histological abnormality was placental abruption which was seen in 6 miscarriages, occasionally on its own, or in combination with maternal vascular malperfusion or acute chorioamnionitis. The second most frequent finding was maternal vascular malperfusion, as found in five placentas, alone or in combination with other pathology. The third most frequent pathology was acute chorioamnionitis, found in four placentas, in combination or alone. Other causes were diffuse chronic villitis due to cytomegalovirus infection and early amnion rupture with anhydramnios and cord obstruction.

CONCLUSIONS

Causes of fetal demise at the end of the second trimester differ little from causes of stillbirth. There is value in using placental histology in late second trimester miscarriages to try to identify the cause of demise.

Perinatal death investigations: What is current practice?

Perinatal death (PD) is a devastating obstetric complication. Determination of cause of death helps in understanding why and how it occurs, and it is an indispensable aid to parents wanting to understand why their baby died and to determine the recurrence risk and management in subsequent pregnancy. Consequently, a perinatal death requires adequate diagnostic investigation. An important first step in the analysis of PD is to identify the case circumstances, including relevant details regarding maternal history, obstetric history and current pregnancy (complications are evaluated and recorded). In the next step, placental examination is suggested in all cases, together with molecular cytogenetic evaluation and fetal autopsy. Investigation for fetal-maternal hemorrhage by Kleihauer is also recommended as standard. In cases where parents do not consent to autopsy, alternative approaches such as minimally invasive postmortem examination, postmortem magnetic resonance imaging, and fetal photographs are good alternatives. After all investigations have been performed it is important to combine findings from the clinical review and investigations together, to identify the most probable cause of death and counsel the parents regarding their loss.

Placental inflammation and its relationship to cervicovaginal fetal fibronectin in preterm birth

OBJECTIVE

Late miscarriage and preterm birth are frequently thought to be associated with inflammation and infection, although in most cases the underlying cause of early delivery remains unknown. The placenta is the organ that links mother and fetus during pregnancy, and postnatal examination may provide useful information about pathophysiology. The relationship between placental pathological lesions and predictive markers of early delivery has not been explored. We sought to characterize preterm deliveries according to placental pathology and relate these to the performance of reliable predictive markers, fetal fibronectin and cervical length.

STUDY DESIGN

This is a retrospective subanalysis from a larger prospective cohort study on sonographic cervical length, quantitative fetal fibronectin and risk of spontaneous preterm birth. Our cohort was comprised of high-risk asymptomatic women attending the Prematurity Surveillance Clinic at St Thomas' Hospital between 2002 and 2015, who went on to have a late miscarriage or preterm delivery (16-36⁺⁶ weeks') and who had available placental histology. The placental pathology of these preterm deliveries was characterized according to the lesions identified, and categorized (according to the Redman classification) into inflammatory (e.g. chorioamnionitis) or non-inflammatory (histologically normal or vascular lesions indicating e.g. malperfusion). We sought to relate placental findings to the performance of reliable predictive markers, in women who delivered early. Standard clinical cut offs for cervical length (<25mm) and fetal fibronectin (>50ng/mL) were used to identify the proportion of preterm births that were accurately predicted by the tests or who showed a false negative result, in relation to their placental histology findings. Binomial logistic regression was carried out to evaluate the relationship between placental inflammation, quantitative fFN and cervical length as continuous variables.

RESULTS

105 women who had a late miscarriage or preterm delivery (16-36⁺⁶ weeks') and available placenta pathology were identified. 66% (42/64) of those with inflammatory placental pathology had a positive fetal fibronectin swab result compared to 15% (6/41) of those with non-inflammatory placental pathology (chi-squared 25.9, 95% CI 31.5 to 65.6, p<0.0001). A logistic regression model subanalysis of women in whom both CL and quantitative fFN results were available (n=66) revealed a highly statistically significant relationship with inflammatory placental lesions (p=0.003 and p=0.001 respectively). Placental inflammation was found to be associated with both increasing levels of fFN and a shortening cervix.

CONCLUSION

There is a significant association between a positive fetal fibronectin result and underlying inflammatory pathology of the placenta, even more so than the recognized relationship with short cervical length. Infective morbidity may be increased in women and neonates with positive fetal fibronectin who deliver preterm.