Letters to the Editor
Lifestyle Modifications, Tubal Flushing to Increase Fertility
TO THE EDITOR: I read with great interest the article, "Infertility," in American Family Physician.1 Although the information was extensive and well referenced, I would like to make three additional points about the current understanding and treatment of infertility.
My first point is the importance of highlighting the two categories of infertility. Primary infertility is the failure to achieve pregnancy during one year of frequent, unprotected intercourse. Secondary infertility is defined as couples who have previously been pregnant at least once, but have been unable to achieve another pregnancy.2
Epidemiologic studies indicate cigarette smoking, abnormal body mass index, and excessive caffeine and alcohol consumption reduce fertility in the female partner.3 Couples with unexplained infertility should be informed of a possible relationship between cigarette smoking and infertility and advised to stop smoking.3 The female partner should be counseled to try to achieve a body mass index between 20 and 27 kg per m2, reduce caffeine intake to no more than 250 mg daily, and reduce alcohol intake to no more than four drinks per week. These changes may enhance natural and assisted conception.4
My last point is the therapeutic role of tubal flushing. Several studies have reported increased pregnancy rates after diagnostic hysterosalpingography.5 A Cochrane review of 11 randomized trials found that tubal flushing with oil-soluble media versus no intervention was associated with a significant increase in pregnancy rate (odds ratio = 3.30; 95% confidence interval, 2.00 to 5.43).5-6
Author disclosure: Nothing to disclose.
REFERENCES
1. Jose-Miller AB, Boyden JW, Frey KA. Infertility. Am Fam Physician 2007;75:849-56.
2. Speroff L, Fritz MA. Clinical Gynecologic Endocrinology and Infertility. 7th ed. Philadelphia, Pa.: Lippincott Williams & Wilkins, 2005.
3. Barbieri RL. The initial fertility consultation: recommendations concerning cigarette smoking, body mass index, and alcohol and caffeine consumption. Am J Obstet Gynecol 2001;185:1168-73.
4. Wittemer C, Ohl J, Bailly M, Bettahar-Lebugle K, Nisand I. Does body mass index of infertile women have an impact on IVF procedure and outcome? J Assist Reprod Genet 2000;17:547-52.
5. Fedorcsák P, Dale PO, Storeng R, Ertzeid G, Bjercke S, Oldereid N, et al. Impact of overweight and underweight on assisted reproduction treatment. Hum Reprod 2004;19:2523-8.
6. Johnson N, Vandekerckhove P, Watson A, Lilford R, Harada T, Hughes E. Tubal flushing for subfertility. Cochrane Database Syst Rev 2005;(2):CD003718.
editor's note: This letter was sent to the authors of "Infertility," who declined to reply.
The Role of Vitamin C in the Treatment of the Common Cold
TO THE EDITOR: The authors of "Treatment of the Common Cold," in American Family Physician, stated that vitamin C is not recommended for active treatment of the common cold.1 Their recommendation was based on a Cochrane review that I coauthored.2
The Cochrane review was limited to placebo-controlled trials in which at least 0.2 g of vitamin C was used per day.2 Most of these trials examined vitamin C administration as regular supplementation and provided strong evidence that vitamin C shortens the duration of colds and alleviates its symptoms. Children benefited more than adults.2 The data also suggested that high doses of vitamin C are more beneficial than low doses.2-6
Stratification of the regular supplementation trials in children by vitamin C dosage shows a tendency for dose dependency. Four trials, using 0.20 to 0.75 g of vitamin C per day, found an average reduction of 7 percent in common cold duration (95% confidence interval [CI], -19 to 5). Six trials with 1 g of vitamin C per day found an average reduction of 18 percent (95% CI, -32 to -3), and two trials using 2 g of vitamin C per day found an average reduction of 25 percent (95% CI, -50 to 0.1). Therefore, the 13.6 percent estimate for common cold reduction we calculated in the Cochrane review2, based on all 12 trials with children who received at least 0.2 g of vitamin C per day, may underestimate the effect of high doses.
Although the regular supplementation trials demonstrate that vitamin C has physiologic effects on the common cold, taking supplements throughout the year to slightly shorten colds does not seem reasonable. Consequently, therapeutic vitamin C supplementation soon after the onset of cold symptoms seems more rational. Few trials have been conducted, and results are not consistent; methodologic variation partially explains the divergence in results.2,5,6
The only trial that compared regular and therapeutic supplementation was conducted in adults.3 The researchers administered 3 g of vitamin C per day and found no difference between regular and therapeutic supplementation.3-5 Furthermore, they found that 6 g of vitamin C per day was associated with twice as much benefit as the 3 g per day dose.3-5 Because no trials have been conducted in children, our review concluded that such trials are warranted.2
Although there is no direct evidence to show that therapeutic vitamin C would affect colds in children, and therapeutic trials with adults are only partly positive,2-6 it may still be reasonable to suggest testing vitamin C to treat colds. The results of a controlled trial are an average for a group. Vitamin C is inexpensive and safe, and its effect on an individual may be much more (or much less) than the benefit suggested by a single trial, or by the pooled results of a meta-analysis.6
Author disclosure: Nothing to disclose.
REFERENCES
1. Simasek M, Blandino DA. Treatment of the common cold. Am Fam Physician 2007;75:515-20.
2. Douglas RM, Hemilä H, D'Souza R, Chalker EB, Treacy B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2004;(4):CD000980.
3. Karlowski TR, Chalmers TC, Frenkel LD, Kapikian AZ, Lewis TL, Lynch JM. Ascorbic acid for the common cold. A prophylactic and therapeutic trial. JAMA 1975;231:1038-42.
4. Hemilä H. Vitamin C, the placebo effect, and the common cold: a case study of how preconceptions influence the analysis of results. J Clin Epidemiol 1996;49:1079-84.
5. Hemilä H. Vitamin C supplementation and common cold symptoms: factors affecting the magnitude of the benefit. Med Hypotheses 1999;52:171-8.
6. Hemilä H. Do vitamins C and E affect respiratory infections? [Academic Dissertation] University of Helsinki, Helsinki, Finland, January 2006:21-7, 36-45, 48-9, 62-3. Accessed August 6, 2007, at: http://ethesis.helsinki.fi/julkaisut/laa/kansa/vk/hemila.
Send letters to Kenny Lin, MD, Assistant Editor, American Family Physician, e-mail: afplet@aafp.org, or 11400 Tomahawk Creek Pkwy., Leawood, KS 66211-6272.
Please include your complete address, e-mail address, telephone number, and fax number. Letters should be fewer than 500 words and limited to six references (including citation of original article) and one table or figure.
Letters submitted for publication in AFP must not be submitted to any other publication. Possible conflicts of interest must be disclosed at time of submission. Submission of a letter will be construed as granting the American Academy of Family Physicians permission to publish the letter in any of its publications in any form. The editors may edit letters to meet style and space requirements.
| Copyright © 2007 by the American
Academy of Family Physicians. |
