Folic Acid and Prevention of Neural Tube Defects

Since the U.S. Public Health Service (USPHS) recommended in 1992 that all women of childbearing age increase their folic acid intake, the blood folate levels of women of reproductive age have increased significantly, but the incidence of neural tube defects has not declined as much as expected, according to a report from the Centers for Disease Control and Prevention (CDC). The report, “Folic Acid and Prevention of Spina Bifida and Anencephaly: 10 Years After the U.S. Public Health Service Recommendation,”is available online at www.cdc.gov/mmwr/preview/mmwrhtml/rr5113a1.htm.

After the 1992 recommendation, efforts were made to increase women's daily use of dietary supplements containing at least 400 mcg of folic acid. In addition, the U.S. Food and Drug Administration in 1998 began requiring fortification of enriched cereal grain products. Substantial increases have not occurred in the reported use of folic acid-containing dietary supplements from 1995 to 2002; the assumption is that the majority of the increase in blood folate levels is the result of consumption of fortified grain products.

Since the institution of fortified cereal grains, the incidence of neural tube defects has declined by approximately 20 to 30 percent — lower than the 50 to 70 percent decrease predicted by the USPHS in 1992 if all women of reproductive age were to take 400 mcg of folic acid daily. The decrease also is lower than predicted on the basis of the rise in blood folate levels. The CDC speculates that women at the highest risk of having neural tube defect-affected pregnancies do not consume as much fortified food, do not have the same level of access to other sources of folic acid, or do not absorb as much folic acid as do women at lower risk.

ACOG Assessment of Cervical Cytology Screening

Despite a recent report that suggested that conventional Papanicolaou (Pap) tests may miss up to one half of all cases of cervical intraepithelial neoplasia (CIN), the test represents the most successful cancer-detection strategy ever developed, according to a new technology assessment by a committee of the American College of Obstetricians and Gynecologists (ACOG). The report, “Cervical Cytology Screening,” appeared in the December 2002 issue of Obstetrics and Gynecology.

Although the Pap test's low rate of sensitivity would be unacceptable for most screening tests, cervical cytology is an extremely effective tool for the eradication of cervical cancer because it takes years or decades for the earliest changes of CIN to progress to invasive cancer, the committee said. It also noted that most cases of CIN regress spontaneously and that most women are screened more than once.

New methods of collection, preparation, and interpretation, along with the development of adjunctive tests such as human papillomavirus DNA testing, have improved the sensitivity of the Pap test without markedly decreasing its specificity, the committee found.

Surgeon General's Report on Women and Smoking

Although nongender-specific risks of smoking have been well publicized, many women are unaware of the tobacco-related risks unique to women, according to a report by the U.S. Surgeon General. The full text of “Women and Smoking: A Report of the Surgeon General” is available online at www.cdc.gov/mmwr/preview/mmwrhtml/rr5112a4.htm.

Since the first Surgeon General's report on women and smoking was published in 1980, an epidemic of tobacco-related diseases has occurred. Lung cancer, once rare among women, currently accounts for 25 percent of all female cancer deaths. Surveys indicate that many women are not aware that lung cancer has surpassed breast cancer as the leading cause of female cancer deaths.

The once-wide gender gap in smoking prevalence has narrowed, and the rate is nearly three times higher among women with only nine to 11 years of education than among college-educated women. Although smoking rates among girls declined in the 1970s and 1980s, much of that progress was lost in the 1990s, and recent data suggest that cigar smoking among women and girls is increasing. Females in the United States lost an estimated 2.1 million years of life in the 1990s as a result of smoking-related deaths.

Smoking has been linked to increased risks for several cancers, including cancer of the cervix, vulva, oropharynx, bladder, pancreas, liver, kidneys, and colorectal system. Women who smoke are also at increased risk for acute myeloid leukemia, coronary heart disease, ischemic stroke, subarachnoid hemorrhage, peripheral vascular atherosclerosis, ruptured abdominal aortic aneurysm, estrogen-deficiency disorders, Graves' ophthalmopathy, peptic ulcers, Crohn's disease, cataracts, and age-related macular degeneration. Limited data suggest that women smokers may be at increased risk for human immunodeficiency virus infection.

Smokers are more likely than non-smokers to be depressed or have anxiety disorders, bulimia, attention deficit disorder, schizophrenia, or alcoholism.

Menstrual disorders associated with smoking include dysmenorrhea, secondary amenorrhea, menstrual irregularity, and younger age at menopause. Women who smoke have increased risks for conception delay and primary and secondary infertility.

Pregnant women who smoke increase the risk for preterm premature rupture of membranes, abruptio placentae, placenta previa, preterm delivery, perinatal mortality (including stillbirth and neonatal deaths), and sudden infant death syndrome. Smoking during pregnancy appears to have decreased over the past decade, although the rate still may be as high as 22 percent.

Some clinical intervention studies have suggested that women may have more difficulty quitting smoking than men, but data show that women are quitting at similar or even higher rates than men. Prevention and cessation efforts generally have similar efficacy rates among women and men. To date, few gender differences in factors related to smoking initiation and cessation have been identified, although adolescent girls are more likely than adolescent boys to respond to smoking cessation programs that include social support.

ACOG Opinion on Use of Enoxaparin During Pregnancy

Anticoagulation therapy with enoxaparin (Lovenox) during pregnancy appears to be safe, according to an opinion from a committee of the American College of Obstetricians and Gynecologists (ACOG). Committee Opinion 276 appeared in the October 2002 issue of Obstetrics and Gynecology.

The committee warned that enoxaparin and other low-molecular–weight heparins are not recommended for pregnant women with prosthetic heart valves. The warning came after reports of valvular thrombosis in patients with prosthetic heart valves who were apparently adequately anticoagulated.

The “Precautions” section for enoxaparin now includes a discussion noting that the rate of congenital anomalies in infants of women who were treated with the drug during pregnancy has not been proven higher than that of the general population. The committee added that the drug does not cross the placenta, providing no biologic plausibility for such a risk, and that the variety of anomalies reported by the manufacturer suggests no specific pathogenic pattern or increased frequency.

Enoxaparin should be used with caution or discontinued 18 to 24 hours before administration of epidural analgesia for pain relief during labor, the committee said.