Balancing hormones may help prevent preterm birthsApril 01, 2009The relationship between two different types of estrogen and a hormone produced in the placenta may serve as the mechanism for signaling labor, according to a new study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM). This finding may help doctors intervene and prevent preterm birth much more effectively. "The trigger for the onset of labor in women has been a puzzle for a long time," says Dr. Roger Smith, MD, PhD, of John Hunter Hospital in Newcastle, Australia and lead author of the study. "Our findings show we may have an answer, and furthermore may be able to delay or advance labor." Humans have two types of estrogen called estradiol (E2) and estriol (E3). When E2 and E3 are in roughly equal amounts there is no drive to labor, but the opposite holds true once one becomes in greater excess than the other. This study evaluated the ratio of E3 to E2 in 500 pregnant women and found that it went up rapidly as labor approached indicating that E3 could stimulate the onset of labor. Dr. Smith and his colleagues then sought to understand what was causing the increase in E3 and they believe they found an answer. In a previous study they showed that a hormone in the placenta, called corticotrophin-releasing hormone (CRH), rises rapidly through pregnancy, peaking at the time of labor. CRH levels rise earlier in women who deliver prematurely and later in women who deliver late, forming a biological clock that regulates the length of pregnancy. Researchers also showed that CRH can act on the adrenal glands of the fetus to stimulate the production of a steroid hormone which the placenta uses to make E3. This study showed a strong relationship between CRH levels in the mother's blood in the weeks before birth and the levels of E3 supporting the view that CRH increases E3. "CRH may be the catalyst for the onset of labor, by driving steroid hormone production in the fetus, which then leads to an increase in E3 so that it exceeds E2," said Dr. Smith. "If this progression is correct, it may explain why women with a baby who dies in utero can still go into labor. In this scenario, levels of E3 would drop making E2 more dominant and triggering the onset of labor." "It may be possible to delay or advance labor by varying the ratio of E3 to E2 by giving either E2 or E3 to the pregnant woman," said Dr. Smith. "It may also be possible to predict the timing of birth by monitoring this ratio between the two estrogens." Dr. Smith notes that this is the first study to show these results and confirmation through further research is needed. The Endocrine Society |
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| Related Preterm Births Current Events and Preterm Births News Articles Global death toll: 1 million premature babies every year More than one million infants die each year because they are born too early, according to the just released White Paper, The Global and Regional Toll of Preterm Birth. Brain malformations significantly associated with preterm birth, Wake Forest research shows New research out of Wake Forest University School of Medicine provides for the first time a solid scientific answer for the long-standing question of whether there is an association between preterm birth and brain malformations. Pre-pregnancy depressed mood may heighten risk for premature birth Researchers trying to uncover why premature birth is a growing problem in the United States and one that disproportionately affects black women have found that pre-pregnancy depressive mood appears to be a risk factor in preterm birth among both blacks and whites. Preterm birth rate drops The nation's preterm birth rate declined slightly in 2007 - a finding that the March of Dimes hopes will prove to be the start of a new trend in improved maternal and infant health. HPV-vaccine may prevent preterm births Chronic human papilloma virus (HPV)-infections can lead to cellular changes in the cervix that can be a pre-stage to cervical cancer. Surgical treatment of these pre-stages gives an increased risk of preterm birth in subsequent pregnancies. The American Academy of Periodontology issues statement on periodontal treatment during pregnancy Research recently presented at the annual meeting of the Society for Maternal-Fetal Medicine found that routine periodontal treatment in pregnant women did not reduce the risk of preterm deliveries. Some previous studies in this area have suggested that periodontal therapy during pregnancy can lessen the chance of adverse pregnancy outcomes. New study explores the relationship between preterm birth and autism spectrum disorder Recent studies have suggested that autism spectrum disorder (ASD) may be more prevalent among children born very prematurely. The early symptoms of ASD are also associated with other conditions related to preterm births, such as cerebral palsy, which can make it difficult to correctly screen children for ASD. Preterm births rise 36 percent since early 1980s New government statistics confirm that the decades-long rise in the United States preterm birth rate continues, putting more infants than ever at increased risk of death and disability. Uncultured bacteria found in amniotic fluids of women who experience preterm births Researchers from Case Western Reserve University and Yale University have made a significant advancement in understanding the cause behind why some pregnant women suffer from inflammations in the inner womb without any signs of an infection. Late preterm births present serious risks to newborns More than half a million babies are born preterm in the United States each year, and preterm births are on the rise. Late preterm births, or births that occur between 34 and 36 weeks (approximately 4 to 6 weeks before the mother's due date), account for more than 70% of preterm births. More Preterm Births Current Events and Preterm Births News Articles |
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