Vitamin C: Promises Not Kept.

Vitamin C has been suggested as beneficial in preventing and curing the common cold, decreasing the incidence of preterm delivery and preeclampsia, decreasing risk of cancer and cardiovascular disease, and improving the quality of life by inhibiting blindness and dementia. In this article, we review the hypothesized mechanisms of these purported health benefits and the evidence behind such claims.

Prenatal vitamins: what is in the bottle?

Nearly all obstetricians routinely prescribe prenatal vitamins to their pregnant patients at the time of the first prenatal visit. Many times, patients' understanding of the health benefits of prenatal vitamins differs substantially from that of the prescribing physician. The following is a review of the most common ingredients found in prenatal vitamins and their purported health benefits.

Vitamin D: hero or hype.

In recent years, vitamin D deficiency has been implicated, by predominantly observational studies, in a wide variety of ailments including skeletal disease, cardiovascular disease, cancer, diabetes, mental and neurologic disorders, and various etiologies of adverse pregnancy outcome. The following is a review of the physiology of vitamin D, clinical signs and symptoms of inadequate and excessive vitamin D, and the literature purporting its many presumed health benefits.

Vitamin A: too much of a good thing?

UNLABELLED: Vitamin A has the unique distinction of being readily available over the counter, yet conferring significant toxic and teratogenic potential. Although vitamin A deficiency is relatively rare in the United States, globally it is the most common cause of blindness. The following is a review of the various forms and derivatives of vitamin A and their associations with potential adverse perinatal outcomes. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After participating in this CME activity, physicians should be better able to identify sources of Vitamin A, distinguish between toxic and non toxic forms of Vitamin A and counsel patients regarding the dosages of Vitamin A that are tolerable during pregnancy.

Placenta previa: does its type affect pregnancy outcome?

Our objective was to compare pregnancy outcomes associated with different types of placenta previa. This is a retrospective analysis of pregnancies complicated by placenta previa, from January 1990 to December 1997. Descriptive statistics and comparison analyses were performed. One hundred seventy-five singleton pregnancies beyond 24 weeks that were complicated by complete, partial, or marginal previa were included. Differences in pregnancy outcomes between complete, partial, and marginal previas were: onset of bleeding (29.9 +/- 4.5 versus 32.5 +/- 6.9 versus 32.7 +/- 5.0 weeks, respectively, p < 0.05), antepartum hospitalization (60.7% versus 38.1% versus 35.1%, respectively, p < 0.05), gestation at delivery (34.7 +/- 3.1 versus 37.4 +/- 2.6 versus 36.1 +/- 3.0 weeks, respectively, p < 0.05), birth weight (2498.3 +/- 746.8 versus 2978.8 +/- 568.3 versus 2813.4 +/- 728.4 g, respectively, p < 0.05), and hysterectomy at time of cesarean delivery (20.5% versus 0% versus 8.1%, respectively, p < 0.05). For all outcome parameters, the partial and marginal previa groups did not differ. Women with complete placenta previa, as diagnosed with modern ultrasound techniques, had poorer pregnancy outcome. They were more likely to deliver prematurely and were more likely to require a hysterectomy at the time of cesarean delivery.