Maternal and fetal factors associated with stillbirth in singleton pregnancies in 13 hospitals across six states in India: A prospective cohort study.

OBJECTIVE: This study aimed to investigate the incidence of and risk factors for stillbirth in an Indian population. METHODS: We conducted a secondary data analysis of a hospital-based cohort from the Maternal and Perinatal Health Research collaboration, India (MaatHRI), including pregnant women who gave birth between October 2018-September 2023. Data from 9823 singleton pregnancies recruited from 13 hospitals across six Indian states were included. Univariable and multivariable Poisson regression analysis were performed to examine the relationship between stillbirth and potential risk factors. Model prediction was assessed using the area under the receiver-operating characteristic (AUROC) curve. RESULTS: There were 216 stillbirths (48 antepartum and 168 intrapartum) in the study population, representing an overall stillbirth rate of 22.0 per 1000 total births (95% confidence interval [CI]: 19.2-25.1). Modifiable risk factors for stillbirth were: receiving less than four antenatal check-ups (adjusted relative risk [aRR]: 1.75, 95% CI: 1.25-2.47), not taking any iron and folic acid supplementation during pregnancy (aRR: 7.23, 95% CI: 2.12-45.33) and having severe anemia in the third trimester (aRR: 3.37, 95% CI: 1.97-6.11). Having pregnancy/fetal complications such as hypertensive disorders of pregnancy (aRR: 1.59, 95% CI: 1.03-2.36), preterm birth (aRR: 4.41, 95% CI: 3.21-6.08) and birth weight below the 10th percentile for gestational age (aRR: 1.35, 95% CI: 1.02-1.79) were also associated with an increased risk of stillbirth. Identified risk factors explained 78.2% (95% CI: 75.0%-81.4%) of the risk of stillbirth in the population. CONCLUSION: Addressing potentially modifiable antenatal factors could reduce the risk of stillbirths in India.

Clinical and immunobiochemical characterization of airborne Peltophorum pterocarpum (yellow gulmohar tree) pollen: a dominant avenue tree of India.

BACKGROUND: Peltophorum pterocarpum (yellow gulmohar, PP) pollen is an important aeroallergen for type I hypersensitivity in the tropics. OBJECTIVE: To isolate and characterize the IgE-binding proteins of PP pollen for the first time. METHODS: Pollen extract was fractionated by a combination of Sephacryl S-200 column and diethylaminoethyl-Sephadex column. Allergen characterization was done by sodium dodecyl sulphate polyacrylamide gel electrophoresis, periodic acid-Schiff staining, enzyme-linked immunosorbent assay, and western blotting. Allergenic activities were determined by in vivo (skin prick test) and in vitro (enzyme-linked immunosorbent assay and histamine release) analyses. To determine whether the carbohydrate chains are involved in immunoreactivity, deglycosylation of PP pollen proteins was performed. RESULTS: SPT results on the respiratory allergic patients of Calcutta showed that 32.77% showed positivity with PP pollen. Eight IgE-reactive protein components were found in crude extract. Optimum IgE-reactive fraction 1 was resolved into five subfractions. The subfraction 1a showed maximum IgE reactivity containing the 28 kDa IgE-reactive component. Periodate oxidation showed that protein component was involved in its IgE binding. Twenty-eight kilodalton IgE reactive protein component was recognized by 75% of PP-sensitive patients in Western blotting. It also induced significant histamine release in sensitive patient sera. CONCLUSIONS: The purified 28 kDa protein is a clinically relevant allergen with a potential for diagnosis and therapy of patients susceptible to PP pollen.

Clinical and immunobiochemical characterization of airborne Delonix regia (Gulmohar tree) pollen and cross-reactivity studies with Peltophorum pterocarpum pollen: 2 dominant avenue trees from eastern India.

BACKGROUND: Delonix regia and Peltophorum pterocarpum pollen are important aeroallergens for type 1 hypersensitivity in the tropics. The IgE-binding proteins of D regia and their cross-allergenity with P pterocarpum pollen have not been evaluated. OBJECTIVES: To isolate and characterize the IgE-binding proteins of D regia pollen for the first time and to investigate the cross-allergenity with P pterocarpum pollen belonging to the same family (Leguminosae). METHODS: Allergenic activities were determined by in vivo and in vitro analyses. Pollen extract was fractionated by a combination of 2 columns (diethyl amino ethyl Sephadex and Sephacryl S-200). Protein components were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, periodic acid-Schiff staining, and immunoblotting. In vitro inhibition tests were performed to evaluate the cross-reactivity. RESULTS: The skin prick test results of the patients with respiratory allergies in Calcutta, India, showed 31.1% positivity with D regia pollen. Nine IgE-reactive protein components were found in the crude extract. An optimum IgE-reactive fraction was resolved into 4 subfractions. Subfraction A, which showed maximum IgE reactivity, contained 2 (96- and 66-kDa) IgE-reactive protein components. The 66-kDa component was found to be glycoprotein. Remarkable cross-reactivity between D regia and P pterocarpum pollen was found on IgE enzyme-linked immunosorbent assay inhibition and dot blotting. Shared IgE-binding components (66, 56, 32, 28, 25, and 23 kDa) were observed between D regia and P pterocarpum pollen extracts, whereas the 96- and 43-kDa components were specific to D regia. CONCLUSION: The purification of the IgE-binding proteins and the identification of the shared/cross-reactive proteins in these taxonomically related pollen members should be helpful for the diagnosis and therapy of patients susceptible to these pollens.

Clinico-immunologic evaluation of allergy to Himalayan tree pollen in atopic subjects in India--a new record.

Exposure to local pollen allergens has a direct bearing on the prevalence of allergic symptoms among the inhabiting atopic population. The populations in the Himalayas and around it are exposed to a variety of pollen grains from trees growing in the region, but the pollen-population interaction has not been clinically investigated. Himalayan tree pollen from five different taxa, i.e. Alnus nitida (AN), Betula utilis (BU), Cedrus deodara (CD), Mallotus phillipensis (MP) and Quercus incana (QI) were evaluated for their allergenicity in the Indian population by in vivo (skin prick test) and in vitro (ELISA) clinico-immunological methods. The presence of specific IgE against these tree pollen in the sera of skin test positive patients was taken as evidence for sensitization to these pollen. The average skin positivity in atopic populations recorded at different allergy centers in India varied from 2.2% against AN, to 4.7% against MP pollen. Significantly raised specific IgE against these pollen were observed in the sera of hypersensitive patients. The sensitization pattern to Himalayan tree pollen in these atopic populations varied. It was concluded that skin prick test positivity and raised IgE antibodies specific to AN, BU, CD, MP and QI established Himalayan tree pollen as important sensitizers in the atopic populations of India. A high incidence of skin sensitivity was observed to pollen antigens of Cedrus deodara, Mallotus phillipensis and Quercus incana in patients of Chandigarh residing in the hills and foothills of the Himalayas while Alnus nitida, Betula utilis and Cedrus deodara were important sensitizers in Delhi patients. The skin sensitization pattern against these pollen was in accordance with the level of exposure to these pollen of the subjects residing in that part of the country.