1999 Publications

Schulkin J. Corticotropin-releasing hormone signals adversity in both the placenta and the brain: regulation by glucocorticoids and allostatic overload. J of Endocrinology 961:349-356, 1999.

Gulcocorticoids regulate corticotropin-releasing hormone (CRH) gene expression in the placenta and the brain. In both the placenta and two extrahypothalamic sites in the brain (the amygdala and the bed nucleus of the stria terminalis), glucocorticoids elevate CRH gene expression. One functional role of the elevation of CRH by glucocorticoids may be to signal adversity. When CRH is over-expressed in the placenta, it may indicate that the pregnancy is in danger, and preterm labor may result. When CRH is over-expressed in the brains of animals, they may become more fearful. Both situations possibly reflect allostatic mechanisms and vulnerability to allostatic overload, a condition in which biological tissue may be compromised.

Wilkins-Haug L., Hill L., Schmidt L., Holzman G.B., Schulkin J. Genetics in Obstetricians' Offices: A Survey Study.  Obstet Gynecol 93:642-647, 1999.

Objective: To investigate obstetricians' genetic knowledge base and practice trends. Method: A questionnaire survey was sent to 1003 ACOG Fellows, 554 (55%) of whom responded. Results from the 446 respondents practicing obstetrics are reported. Results: The majority of obstetricians surveyed (85.6%) reported completing standardized genetic-history forms for prenatal patients, and about half (48%) performed their own invasive diagnostic procedures. Most (87%) had access to genetic counselors. For aneuploidy risks associated with advanced maternal age, up to 69% of respondents provided at least some patient counseling in their office. Physician knowledge of risk assessment and diagnostic testing in the areas of aneuploidy and neural tube defects was very good; however, for single gene disorders such as cystic fibrosis, Tay-Sachs disease, and sickle cell disease, correct risk assessment or appropriate test selection presented difficulties for at least half of the respondents. Respondents cited the rapidity of changes in genetic testing as the greatest obstacle to providing genetic information to patients. Conclusion: Obstetricians' knowledge of inheritance and test selection pertaining to single-gene disorders was more limited than that for aneuploidy and neural tube defects. Comparable deficits were noted in patient-education efforts for single-gene disorders.

Power M.L., Holzman G.B., Schulkin J. Knowledge and Clinical Practice Regarding Calcium Nutrition Among Obstetrician-Gynecologists. Obstet Gynecol, 94:421-426, 1999.

Objective: To survey the knowledge and attitude toward nutrition among practicing obstetrician-gynecologists, using calcium as a specific example. Methods: Our survey on calcium nutrition consisted of 29 questions divided into four categories: demographic information, professional interests and clinical practice, knowledge and opinions, and education. We mailed this survey to the 244 ACOG Fellows who are members of the Collaborative Ambulatory Research Network and to a random sample of 756 Fellows who are not members of the Collaborative Ambulatory Research Network. Results: Most (75.4%) respondents consider making dietary recommendations an important part of their practice. Interest in nutrition was correlated significantly with its perceived importance in clinical practice and was associated with a greater self-reported likelihood of making dietary recommendations to patients and referring patients for nutrition counseling. Nutrition was of greater importance to women and older respondents. Female physicians were more likely to make dietary recommendations to patients. Male physicians were more likely to recommend nonfoods and higher fat foods as sources as dietary calcium. The daily calcium intake that obstetrician-gynecologists recommended for different types of patients varied widely but did not differ between male and female respondents. The responses to the knowledge questions concerning calcium metabolism were predominantly "don't know." Conclusions: although specific knowledge of calcium metabolism and regulation was incomplete, obstetrician-gynecologists generally recognized the importance of nutrition in their clinical practice. Being older and female independently increased the perceived importance of nutrition.

Power M.L., Heaney R.P., Kalkwarf H.J., Pitkin R.M., Schulkin, J. The Role of Calcium in Health and Disease. Am J Obstet Gynecol, 181: 1560-1569, 1999.

Skeletal fragility at the end of life (osteoporosis) is a major source of morbidity and mortality. Adequate calcium intake from childhood to the end of life is critical for the formation and retention of a healthy skeleton. High intakes of calcium and vitamin D potentiate the bone loss prevention effects of hormone replacement therapy in postmenopausal women. Pregnancy and lactation are not risk factors for skeletal fragility, although lactation is associated with a transient loss of bone that cannot be prevented by calcium supplementation. Low calcium intake has been implicated in the development of hypertension, colon cancer, and premenstrual syndrome, and is associated with low intakes of many other nutrients. Encouraging increased consumption of calcium-rich foods has the potential to be a cost effective strategy for reducing the fracture incidence later in life, and for increasing patients' diet quality and overall health.

Abrahamson S., Baron J., Elstein A., Hammond W.P., Holzman G.B., Marlow B., Taggart M.S., Schulkin J. Continuing Medical Education Life: Eight Principles. Academic Medicine, 74:1288-1294, 1999.

The educational needs of obstetricians and gynecologists are dynamic, as the professional aspects of the specialty are changing. Today, as a requirement of certification, generalists in obstetrics and gynecology must acquire broad knowledge and competency required to provide primary and preventive care to adult women. Continuing medical education represents a primary strategy for acquiring and sustaining the knowledge base for effective office-based care. Several approaches that emphasize small group interactions, self-directed learning and problem-based learning may be particularly beneficial.

Majzoub J., McGregor J., Lockwood C., Smith R., Snyder-Taggart M., Schulkin J.  A Central Theory of Preterm and Term Labor: Putative Role for Corticotropin-Releasing Hormone. Am J of Obstetrics and Gynecology 180:S232-S241, 1999.

Near the end of human pregnancy the concentration of placental corticotropin-releasing hormone in maternal blood rises exponentially. The rate of elevation of corticotropin-releasing hormone and its duration through time have been linked to the time of onset labor. Paradoxically, although glucocorticoids are known to inhibit corticotropin-releasing hormone production within the hypothalamic-pituitary-adrenal axis, cortisol actually increases corticotropin releasing hormone levels in several areas outside the hypothalamus, including the placenta. Placental corticotropin-releasing hormone may be an important component of a system that controls the normal maturation of the fetus and signals the initiation of labor. Abnormal elevations in corticotropin-releasing hormone, which may be a hormonal response to stressors arising in either the mother, placenta, or fetus, may prove to precipitate in the premature onset of parturition.


Michael Power, PhD

Carrie Snead, MA


American College of Obstetricians and Gynecologists
409 12th Street SW, Washington, DC  20024-2188