The influence of air pollution on gestational age at delivery and birthweight in patients with or without respiratory allergy: A nested case-control study.

INTRODUCTION: Air pollution is a current major health issue. The burden of airborne pollutants and aeroallergen levels varies throughout the year, as well as their interaction and consequences. Prenatal exposure during pregnancy has been associated with adverse perinatal outcomes. The aim of this study was to evaluate the impact of air pollutants on perinatal outcomes in patients with or without respiratory allergy. MATERIAL AND METHODS: Nested case-control retrospective study on 3006 pregnant women. Correlations between concentrations of common pollutants in each trimester of pregnancy and on average during the whole pregnancy and both gestational age at delivery and birthweight were studied. Pearson's correlation coefficient and binary logistic regression were used. RESULTS: In general, pollutants correlated more strongly with birthweight than with gestational age at delivery. Nine-month NO2 , SO2 , CO, and benzene, and second-trimester CO negatively correlated with birthweight, whereas only first-trimester NO2 showed a very mild correlation with gestational age at delivery. Negative correlations between pollutants and birthweight were much stronger in the respiratory allergy group (n = 43; 1.4%) than in the non-allergic group. After adjustments, the most significant predictive pollutant of birthweight was SO2 in both groups. The best predictive model was much stronger in the allergic group for third-trimester SO2 (R2 = 0.12, p = 0.02) than in the non-allergic group for total SO2 (R2 = 0.002, p = 0.02). For each unit that SO2 increased, birthweight reduced by 3.22% vs. 1.28% in each group, respectively. CONCLUSIONS: Air pollutant concentrations, especially SO2 , negatively influenced birthweight. The impact of this association was much stronger and more relevant in the group of women with respiratory allergies.

The influence of maternal respiratory allergy on obstetrics and perinatal outcomes: A nested case-control study.

OBJECTIVE: To evaluate the influence of respiratory allergy on obstetrics and perinatal outcomes. METHODS: A nested case-control retrospective study on 41 035 pregnant women. Obstetrics and perinatal outcomes of women with or without respiratory allergy were compared. Rates of preterm delivery (<37 weeks of gestation), low birth weight (<2500 g), neonatal acidosis (pH < 7.20), low 5-min APGAR score (<7), cesarean section rate and indications, and perinatal morbidity and mortality were analyzed. Results are expressed as number and percentages. χ2 and Fisher exact tests were used for comparisons. Logistic regression was used. Statistical significance was set at 95% level (P < 0.05). RESULTS: A total of 724 (1.8%) patients had respiratory allergy, and their rates of preterm delivery and low birth weight were significantly higher than those of control women (both P < 0.001). Nevertheless, analyzing the causes, multiple gestation rate was significantly higher in this group, and adjusting by this, no statistical difference was found in any of the perinatal outcomes studied. In addition, in vitro fertilization and sterility were also significantly higher in the respiratory allergy group (both P < 0.001). CONCLUSION: Women with respiratory allergy are at higher risks of prematurity and low birth weight but these results are mediated by sterility, in vitro fertilization, and multiple gestation rate. Nonetheless, participation of inflammatory mechanisms should be further studied.

[Anti-D isoimmunization severe in a twin pregnancy. Case report]. / Isoinmunización grave anti-D en una gestación gemelar. Caso clínico.

Perinatal hemolytic disease occurs secondary to a hemolytic phenomenon of immune origin resulting in fetal or neonatal anemia. A 38-year-old pregnant woman was referred to the Department of high risk Obstetrics, Hospital Universitario La Paz Madrid because of presenting a dichorionic diamniotic twin pregnancy spontaneously, pre-pregnancy diabetes poorly controlled and severe alloinmunization anti-D. Her first pregnancy ended in a normal delivery at term; in the period of 4 years, she has three newborn with 36, 34 and 40 weeks respectively, who die with a week of life. After that, two intrauterine fetal death occur at 26 weeks of gestation. The patient who is RhD negative, suffers anti-D inmunization with a antibody titration of 1/1024 with 14 weeks of gestation. Twelve plasmapheresis, eight doses of anti-D inmunoglobulins and intrauterine transfusions has been the treatment received. A severe anemia is found during the ultrasound control of the middLe cerebral artery peak systolic velocity in both twins since the 16th week. It remains stable thanks to the treatment. Finally at the 28th week of gestation, pregnancy is terminated with a cesarean section. The twins are born alive and premature, but with good general state. The measurement of the middle cerebral artery peak systolic velocity predicts moderate-severe fetal anemia cases, which are the most important in the clinical management because of the need of active treatment or finish the pregnancy.