Smoking during pregnancy: a significant cause of neonatal thyroid enlargement
Article Abstract:
A detoxification product of one component of cigarette smoke (thiocyanate, product of detoxification of hydrogen cyanide) can cause goiters (enlarged thyroid glands). Since thiocyanate in the blood (serum thiocyanate, or SCN) can cross the placenta, it was of interest to see whether infants born to women who smoked during pregnancy had enlarged goiters or other thyroid abnormalities. Accordingly, 82 randomly selected mothers with no history of thyroid disease were studied; their smoking status was classified as nonsmoker; light (fewer than 3 cigarettes per day, 58 women); moderate (between 3 and 15 cigarettes per day, 12 women); or heavy (more than 15 cigarettes per day, 12). Levels of SCN and thyroid hormones and other substances relevant to thyroid function were determined from blood sampled from the infants' umbilical cords; urinary iodine (which helps show whether the thyroid is healthy) was measured in the mother after delivery. Thyroid volume was examined in the newborns by ultrasonography. Results showed that women who smoked had higher levels of SCN, and heavy smokers had higher levels than light smokers. Higher cord SCN levels were associated with elevated blood thyroglobulin (a protein stored in the thyroid from which thyroid hormones are made), and with lower birthweight. Greater thyroid volume in the newborn was significantly correlated with higher cord SCN concentrations (when corrected for birthweight). The maternal iodine measurements were borderline normal. The data, taken together, indicate that goiter in newborns from the region studied (Brussels, where the condition is a rarity) may be the result of low iodine levels induced by elevations in SCN concentrations. SCN also interferes with the utilization of iodine by the placenta, further affecting its uptake by the fetus. These abnormalities could also lead to increased blood levels of thyroglobulin. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: British Journal of Obstetrics and Gynecology
Subject: Health
ISSN: 0306-5456
Year: 1991
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Polyhydramnios and associated maternal and fetal complications in singleton pregnancies
Article Abstract:
Polyhydramnios is a complication of pregnancy characterized by an excess of amniotic fluid, the liquid that surrounds the fetus. This disorder occurs in 0.4 to 1.2 percent of pregnancies and is associated with a high fetal death rate due to fetal defects, incomplete fetal development, and maternal diabetes; it may also be associated with pre-eclampsia, another complication of pregnancy. Pre-eclampsia, or toxemia of pregnancy, is characterized by high blood pressure, headaches, albumin (a blood protein) in the urine, and accumulation of water in the lower extremities. The disorders of the mother and fetus associated with polyhydramnios were assessed in 537 single pregnancies complicated by polyhydramnios. Maternal complications and fetal abnormalities did not occur in 248 of the 537 pregnancies, and the overall fetal death rate was 2.4 percent. The death rate increased to 13.1 percent when pre-eclampsia was also present; 10 percent with pregnancy-related diabetes; and 7.6 percent with other complications. The death rate at birth was 61.4 percent when polyhydramnios was associated with malformation of the fetus or the placenta (the source of nourishment for the fetus). Malformations involved the central nervous system in 31 percent of these cases; the skeletal and muscle systems in 12 percent; and the gastrointestinal system in 10 percent. Placental chorioangioma (a tumor of the chorion portion of the placenta) developed in two patients, resulting in death. The fetal death rate was increased five times for women with low excretion of the hormone metabolic product, estriol. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: British Journal of Obstetrics and Gynecology
Subject: Health
ISSN: 0306-5456
Year: 1990
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