Angiogenic proteins, placental weight and perinatal outcomes among pregnant women in Tanzania

Feto-placental Unit: From Development to Function

The placenta is an intriguing organ that allows us to survive intrauterine life. This essential organ connects both mother and fetus and plays a crucial role in maternal and fetal well-being. This chapter presents an overview of the morphological and functional aspects of human placental development. First, we describe early human placental development and the characterization of the cell types found in the human placenta. Second, the human placenta from the second trimester to the term of gestation is reviewed, focusing on the morphology and specific pathologies that affect the placenta. Finally, we focus on the placenta's primary functions, such as oxygen and nutrient transport, and their importance for placental development.

Placental findings in singleton stillbirths: a case-control study from a tertiary-care center in India

OBJECTIVES

Placental examination in a case of stillbirth can provide insight into causative/associated factors with fetal demise. The aim of this study was to compare placental and umbilical cord pathologies in singleton stillbirth and livebirth placentas, and to find prevalence of various associated maternal and fetal clinical factors.

METHODS

This case-control study was conducted at a tertiary-care center in India over a period of 20 months. About 250 women who delivered stillborn fetus ≥28 weeks' gestation and 250 maternal-age-matched controls were recruited. Sociodemographic and clinical details were noted and placental gross and microscopic examination was done. Placental findings were compared between stillbirth and livebirth (overall), preterm stillbirth and preterm livebirth as well as term stillbirth and term livebirth in six categories - placenta gross, cord gross, membranes gross, maternal vascular malperfusion, fetal vascular malperfusion and inflammatory response. Prevalence of 11 maternal and fetal factors were studied in all categories of placental findings in both livebirth and stillbirth.

RESULTS

Placental findings in all six categories were significantly associated with stillbirths (p<0.05). The placental findings associated with stillbirth with highest odds included placental hypoplasia (OR 9.77, 95% CI 5.46-17.46), necrotizing chorioamnionitis (OR 9.30, 95% CI 1.17-73.96) and avascular villi (OR 8.45, 95% CI 3.53-20.25). More than half of the women with stillbirths had medical disorders (n=130, 52.0%) and the most prevalent was hypertensive disorder (n=45, 18.0%).

CONCLUSIONS

Changes in placenta are associated with development of stillbirth. Therefore, antenatal investigations to identify placental dysfunction should be investigated to determine whether these reduce stillbirth. Also, placental examination in a case of stillbirth can detect/diagnose many maternal/fetal conditions and thereby can help in preventing future stillbirths.

Malaria in Pregnancy: From Placental Infection to Its Abnormal Development and Damage

Malaria remains a global health burden with Plasmodium falciparum accounting for the highest mortality and morbidity. Malaria in pregnancy can lead to the development of placental malaria, where P. falciparum-infected erythrocytes adhere to placental receptors, triggering placental inflammation and subsequent damage, causing harm to both mother and her infant. Histopathological studies of P. falciparum-infected placentas revealed various placental abnormalities such as excessive perivillous fibrinoid deposits, breakdown of syncytiotrophoblast integrity, trophoblast basal lamina thickening, increased syncytial knotting, and accumulation of mononuclear immune cells within intervillous spaces. These events in turn, are likely to impair placental development and function, ultimately causing placental insufficiency, intrauterine growth restriction, preterm delivery and low birth weight. Hence, a better understanding of the mechanisms behind placental alterations and damage during placental malaria is needed for the design of effective interventions. In this review, using evidence from human studies and murine models, an integrated view on the potential mechanisms underlying placental pathologies in malaria in pregnancy is provided. The molecular, immunological and metabolic changes in infected placentas that reflect their responses to the parasitic infection and injury are discussed. Finally, potential models that can be used by researchers to improve our understanding on the pathogenesis of malaria in pregnancy and placental pathologies are presented.

Effect of gestational weight gain on placental weight: A single tertiary referral center study of Japanese women

AIM

The effect of gestational weight gain on placental weight has not been elucidated. We aimed to examine the effect of body weight gain during pregnancy on the Japanese standardized z-score of placental weight, based on the pre-pregnancy body mass index.

METHODS

This retrospective cohort study included Japanese women with singleton pregnancies who gave birth during 2013-2019 at Ohta Nishinouchi Hospital. Participants (n = 3610) were categorized by their pre-pregnancy body mass index: G1 (<18.5 kg/m² ), G2 (18.5 to <20.0 kg/m² ), G3 (20.0 to <23.0 kg/m² ), G4 (23.0 to <25.0 kg/m² ), and G5 (≥25.0 kg/m² ). Multiple linear regression analysis was used to identify associations between insufficient or excessive gestational weight gain in each body mass index category and z-score of placental weight, with adjustments for maternal age, assisted reproductive technology, and maternal pre-pregnancy conditions, such as hypertension, diabetes mellitus, myoma uteri, and uterine anomalies.

RESULTS

Among the 3610 women assessed, 479, 692, 1292, 435, and 711 were in G1-G5, respectively. In G1, G3, and G4, excessive weight gain increased the placental weight z-score ([B: 0.50, 95% confidence interval [CI]: 0.23-0.76], [B: 0.19, 95% CI: 0.19-0.33], and [B: 0.18, 95% CI: 0.10-0.26]). Insufficient weight gain decreased the placental weight z-score in G3 (B: -0.19, 95% CI: -0.33 to -0.06) and G4 (B: -0.21, 95% CI: -0.29 to -0.13) women.

CONCLUSION

The effect of weight gain during pregnancy on placental size varies by pre-pregnancy body mass index. This result may guide personalized pre-conception counseling to improve the outcomes of offspring.

Placental hypoxia: What have we learnt from small animal models?

Intrauterine hypoxia is a feature of pregnancy complications, both at high altitude and sea level. To understand the placental response to reduced oxygen availability, small animal models of maternal inhalation hypoxia (MIH) or reduced uterine perfusion pressure (RUPP) may be utilised. The aim of this review was to compare the findings of those studies to identify the role of oxygen availability in adapting placental structural and functional phenotypes in relation to fetal outcome. It also sought to explore the evidence for the involvement of particular genes and protein signalling pathways in the placenta in mediating hypoxia driven alterations. The data available demonstrate that both MIH and RUPP can induce placental hypoxia, which affects placental structure and vascularity, as well as glucose, amino acid, calcium and possibly lipid transport capacity. In addition, changes have been observed in HIF, VEGF, insulin/IGF2, AMPK, mTOR, PI3K and PPARγ signalling, which may be key in linking together observed phenotypes under conditions of placental hypoxia. Many different manipulations have been examined, with varied outcomes depending on the intensity, timing and duration of the insult. Some manipulations have detrimental effects on placental phenotype, viability and fetal growth, whereas in others, the placenta appears to adapt to uphold fetal growth despite the challenge of low oxygen. Together these data suggest a complex response of the placenta to reduced oxygen availability, which links to changes in fetal outcomes. However, further work is required to explore the role of fetal sex, altered maternal physiology and placental molecular mechanisms to fully understand placental responses to hypoxia and their relevance for pregnancy outcome.

Relationship between inflammatory markers, glycated hemoglobin and placental weight on fetal outcomes in women with gestational diabetes

OBJECTIVE

The aim of this study was to evaluate the relationship between inflammatory cytokines, placental weight, glycated hemoglobin and adverse perinatal outcomes (APOs) in women with gestational diabetes mellitus (GDM).

SUBJECTS AND METHODS

This was a prospective, longitudinal and observational study conducted from April 2004 to November 2005 in Bauru, Brazil. Included patients had singleton pregnancies and performed a 100 g OGTT and had the levels of C-reactive protein (CRP), interleukin (IL)-6, TNF alfa and glycated hemoglobin (HbA1c) determined at 24-28th gestation weeks.

RESULTS

A total of 176 patients were included, of whom 78 had the diagnosis of GDM (44.3%). Multivariate analysis demonstrated that HbA1c, age, body mass index (BMI) and previous history of GDM were independent predictors for GDM diagnosis. ROC curve indicated that HbA1C levels ≥ 5.1% at 24-28 weeks gestation were associated with GDM. No difference was found in IL-6, tumor necrosis factor alpha (TNF-alpha) and CRP serum levels in women with and without GDM. Multivariate analysis showed that placental weight was significantly associated with APOs (p < 0.005), with a cut-off value of 610 grams as demonstrated by the ROC curve.

CONCLUSION

Placental weight ≥ 610 grams and HbA1C ≥ 5.1% were found to be associated with APOs and GDM, respectively, and their evaluation should be part of prenatal care routine.

Placental Neuropeptide Y ( NPY) and NPY receptors expressions and serum NPY levels in preeclampsia

IMPACT STATEMENT

Neuropeptide Y (NPY) has been reported as a vasoconstrictive substance which might be associated with preeclampsia. The novel findings of this study were that Y1R, Y2R, and Y5R expressions were significantly lower in the PE than the NP group. Moreover, the NPY receptor expression ratio between the PE/NP groups was lowest for Y2R (0.27) compared to Y1R (0.42) and Y5R (0.40) suggestive of a reduction of this receptor in the preeclampsia group. Our results suggested that decreased Y2R mRNA in the PE group might be associated with abnormalities of placental angiogenesis which probably contributes to the pathophysiology of preeclampsia.

Parâmetros utilizados na avaliação de bem-estar do bebê no nascimento

Objectivo: identificar parâmetros que se utilizan para evaluar el bienestar del recién nacido.Síntesis del contenido: revisión integrativa de la literatura, realizada en las bases PubMed y Biblioteca Virtual de Salud (bvs), que utilizó los descriptores “apgar score”, “neonatal outcomes”, “fetal vitality” y “health services evaluation”. El recorte temporal fue de enero del 2011 a diciembre del 2016. Se importaron los resúmenes para el software Endnote Web®, para la remoción de duplicados y los remanentes exportados para el software Covidence®, lo que permitió la selección de la muestra final por dos investigadoras, de forma independiente. La muestra final incluyó 17 estudios. Los parámetros más utilizados fueron admisión del neonato en Unidad de Cuidados Intensivos en las primeras 24 a 48 horas de vida y el índice de Apgar, pero hubo variaciones en la mensuración de esos parámetros entre los estudios. Otros parámetros fueron: peso al nacer, temperatura corporal, natimortalidad y mortalidad neonatal. El Apgar, a pesar de utilizado mundialmente, posibilita subjetividad en la evaluación de algunas variables; este puede evaluar la respuesta del bebé a las maniobras empleadas en el atendimiento en sala de parto, pero no debe ser un parámetro decisorio para instituir o no maniobras de reanimación.Conclusión: algunos parámetros fueron comunes entre los estudios, sin embargo pueden agregarse otros parâmetros al abordar patologías específicas. Se considera importante entrenar enfermeiros en la medición del Apgar, pues son professionales responsables por el cuidado de la madre y el bebé 24 horas del día y, en muchos servicios, por la primera atención del recién nacido.