Folic acid supplements during pregnancy and risk of miscarriage.

BACKGROUND: Although taking supplements that contain 400 microg of folic acid before and during early pregnancy reduces a woman's risk for having a baby with a neural-tube defect (NTD), the effects of such supplements on other pregnancy outcomes remain unclear. We examined whether the use of such supplements affects the occurrence of miscarriage. METHODS: Participants were women in China who had taken part in a recent folic acid campaign to prevent NTDs and who had registered in this campaign before they became pregnant for the first time. We examined the risk for miscarriage among women who had confirmed pregnancies and who had or had not taken pills containing only 400 microg of folic acid before and during early pregnancy. RESULTS: The overall rate of miscarriage was 9.1% (2155/23806). The rates of miscarriage among women who had and had not taken folic acid pills before and during the first trimester were 9.0% and 9.3%, respectively (risk ratio 0.97 [95% CI 0.84-1.12]). The distributions of gestational age at pregnancy diagnosis and at miscarriage were similar for both groups of women. INTERPRETATION: In this population-based study of a cohort of women whose use of folic acid supplements while pregnant had been previously documented and who had been pregnant for the first time, we found no evidence that daily consumption of 400 microg of folic acid before and during early pregnancy influenced their risk for miscarriage.

Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention.

BACKGROUND AND METHODS: Periconceptional administration of folic acid can reduce a woman's risk of having a fetus or infant with a neural-tube defect. As part of a public health campaign conducted from 1993 to 1995 in an area of China with high rates of neural-tube defects (the northern region) and one with low rates (the southern region), we evaluated the outcomes of pregnancy in women who were asked to take a pill containing 400 microg of folic acid alone daily from the time of their premarital examination until the end of their first trimester of pregnancy. RESULTS: Among the fetuses or infants of 130,142 women who took folic acid at any time before or during pregnancy and 117,689 women who had not taken folic acid, we identified 102 and 173, respectively, with neural-tube defects. Among the fetuses or infants of women who registered before their last menstrual period and who did not take any folic acid, the rates of neural-tube defects were 4.8 per 1000 pregnancies of at least 20 weeks' gestation in the northern region and 1.0 per 1000 in the southern region. Among the fetuses or infants of the women with periconceptional use of folic acid, the rates were 1.0 per 1000 in the northern region and 0.6 per 1000 in the southern region. The greatest reduction in risk occurred among the fetuses or infants of a subgroup of women in the northern region with periconceptional use who took folic acid pills more than 80 percent of the time (reduction in risk, 85 percent as compared with the fetuses or infants of women who registered before their last menstrual period and who took no folic acid; 95 percent confidence interval, 62 to 94 percent) [corrected]. In the southern region the reduction in risk among the fetuses or infants of women with periconceptional use of folic acid was also significant (reduction in risk, 41 percent; 95 percent confidence interval, 3 to 64 percent). CONCLUSIONS: Periconceptional intake of 400 microg of folic acid daily can reduce the risk of neural-tube defects in areas with high rates of these defects and in areas with low rates.

Recommended Childhood Immunization Schedule--United States, January-June 1996.

In January 1995, the Recommended Childhood Immunization Schedule, developed by the Advisory Committee on Immunization Practices (ACIP) the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP), was published. This unified schedule represented the first such schedule developed through a collaborative process among the recommending groups, the pharmaceutical manufacturing industry, and the Food and Drug Administration. This process is intended to maintain a common childhood immunization schedule and to work toward further simplification of the schedule. The Recommended Childhood Immunization Schedule--United States, January-June 1996 (Figure 1) has been updated by these groups to incorporate newly licensed and/or recommended vaccines and to clarify specific issues. Since publication of the schedule in 1995, Varicella Zoster Virus Vaccine (Var) has been licensed, and recommendations for adolescent hepatitis B vaccination have been developed. The following changes are incorporated into the Recommended Childhood Immunization Schedule.

Recommended childhood immunization schedule United States--1995. American Academy of Pediatrics and the Advisory Committee on Immunization Practices.

The need for a single childhood immunization schedule prompted the unification of previous vaccine recommendations made by the American Academy of Pediatrics (AAP) and the Advisory Committee on Immunization Practices (ACIP). In addition to presenting the newly recommended schedule for the administration of childhood vaccines, this article addresses the previous differences between the AAP and ACIP schedules, and provides the rationale for changing previous recommendations.

Preschool children at high risk for measles: opportunities to vaccinate.

OBJECTIVES: In 1989 and 1990 the United States experienced a measles epidemic with more than 18,000 and 27,000 reported cases, respectively. Nearly half of all persons with measles were unvaccinated preschool children under 5 years of age. We sought to identify potential sites for vaccine delivery. METHODS: Preschool children with measles were surveyed in five inner cities with measles outbreaks in 1989 to 1990 to assess the children's use of health care services and federal assistance programs before contracting measles. RESULTS: Of 972 case children surveyed, 618 (64%) were eligible for measles vaccination at measles onset. Of those, 93% had previously visited a health care provider (private physician, public clinic, hospital emergency department, or hospital outpatient department) and 65% were enrolled in a federal assistance program (AFDC, WIC, or food stamps). Based on parent-reported reasons for health care visits, in Dallas and New York City, health care providers of 24% of 172 children may have missed at least one opportunity to administer measles vaccine. CONCLUSIONS: Many potential opportunities exist to raise the vaccination coverage of unvaccinated preschool children. These opportunities depend on (1) health care providers taking advantage of all opportunities to vaccinate, and (2) immunization services being linked to federal assistance programs.

High attack rates and case fatality during a measles outbreak in groups with religious exemption to vaccination.

Beginning in October, 1990, a large measles outbreak involving predominantly unvaccinated preschool age children occurred in Philadelphia. By June, 1991, 938 measles cases had been reported to the Philadelphia Health Department. In addition to these cases, 486 cases and 6 measles-associated deaths occurred between November 4, 1990, and March 24, 1991, among members of 2 Philadelphia church groups that do not accept vaccination. We identified measles cases and collected information on symptoms and potential risk factors for complications. Telephone interviews were conducted to collect demographic and clinical information on measles cases in church member households. We identified 486 measles cases among 892 mostly unvaccinated church members. Age-specific attack rates were highest among children 1 to 4 years of age (94%) and 5 to 14 years of age (91%). Five (83%) of the 6 deaths occurred in females, 3 of whom had underlying illnesses. The overall case-fatality rate was 1.2%. The case-fatality rate was 2% for females, 0.4% for males (P = 0.22), 1.7% for primary cases and 0.7% for secondary household cases (P = 0.67). Only one of the children who died had received medical care. Measles spread rapidly in this group, sparing few susceptible individuals. Lack of medical care and underlying disease appear to have contributed to the high case-fatality rate in the church communities.

Successes and failures in vaccine delivery: evaluation of the immunization delivery system in Puerto Rico.

The objective of this study was to evaluate immunization delivery and determine reasons for low coverage among preschool-age public clinic attendees in Puerto Rico. In 25 randomly selected clinics, coverage and missed immunization opportunities were assessed in 273 children aged 2 to 59 months, exist interviews were conducted with parents, and providers were interviewed. Two neighborhoods close to the clinics were surveyed to determine parental knowledge about immunizations, and the vaccination status of children in these neighborhoods was assessed. Two hundred seventy-three clinic attendees were interviewed. Among 229 (84%) with vaccination cards, only 126 (55%) had received all indicated vaccines by completion of the clinic visit. Forty-five percent of children with cards in the household survey were not up-to-date. Of 171 (75%) clinic attendees eligible for vaccination at the visit, 118 (69%) missed one or more immunizations at the visit. In addition, half of all children had previously missed one or more immunizations when they had received another vaccine. Missed opportunities occurred because of nonavailability of vaccines, lack of integration of services, provider misconceptions about contraindications, and failure to administer vaccines simultaneously. Other problems included barriers to immunization services and lack of information and education activities. It is concluded that deficiencies in immunization delivery substantially delay immunization and reduce coverage.

Epidemiology of measles in the United States in 1989 and 1990.

During 1989 and 1990 measles incidence increased sharply in the United States. We compared cases reported during these years with those reported between 1981 and 1988. Incidence increased 462% in 1989, and incidence in 1990 (11.2/100,000) was the highest in more than a decade. Although all ages were affected the greatest increases were in children < 5 years and in adults. Incidence was 7- to 10-fold higher among racial/ethnic minority preschoolers than whites, and 80% of vaccine-eligible preschool age cases were unvaccinated. Complications occurred in 9418 (20.5%) cases, most frequently in young children and adults. Large urban outbreaks affecting predominantly unvaccinated preschoolers were common; 47% of all cases reported in 1990 were associated with 5 outbreaks. Reasons for the increased incidence are not clear. Current information suggests no change in vaccination coverage among preschool age children or in vaccine efficacy. Continued surveillance and evaluation of epidemiologic and laboratory data are necessary. The most pressing need is to improve age-appropriate vaccination among preschool age children.

Breast milk composition and bile salt-stimulated lipase in well-nourished and under-nourished Nigerian mothers.

Breast milk was analysed in 9 under-nourished Nigerian mothers and 23 well-nourished mothers who served as controls. Milk from the under-nourished mothers contained adequate amounts of lactose and total triglycerides, but had significantly lower bile salt-stimulated lipase activity (BSSL); their mean BSSL activity was only about 50% of the activity in milk from the control group. Total milk protein was also significantly lower than for the controls (1.45 vs. 1.09 g/dl, respectively; P less than 0.01). Our findings may have nutritional implications for breast-fed infants of under-nourished nursing mothers.

Clofibrate does not alter cyclic nucleotide metabolism in muscle.

Clofibrate is a hypolipidemic agent that causes muscle protein breakdown in rats, and an acute muscular syndrome in man. It also inhibits adenylate cyclase in fat tissue. Muscle protein metabolism has been shown to be regulated by cyclic nucleotides. In the present experiments were measured several parameters of cyclic nucleotide metabolism to determine the role that cyclic nucleotides play in clofibrate-induced muscle protein degradation. It was found that clofibrate treatment did not alter cyclic nucleotide levels, nor did it change the activities of basal or hormone-stimulated adenylate cyclase, or cyclic nucleotide phosphodiesterase in muscle. Our results suggest that muscle protein breakdown in clofibrate-treated rats is not regulated by cyclic nucleotides.

Definition of myocardial perfusion by continuous infusion of krypton-81m.

Krypton-81m, a radionuclide emitting a 190 kev gamma ray, has a half-life of 13 seconds. It is a radioisotope of an inert water-soluble noble gas and is produced at a constant rate by spontaneous decay of rubidium-81 in an 81Rb-81mKr generator-delivery system. Delivery is through a minibore Teflon catheter that can be threaded through a standard no. 7 or 8F angiographic catheter. The generator is eluted by 5 percent dextrose-in-water, delivered by infusion pump at 1.5 ml/min, and the eluate is infused intraarterially directly into any organ. Delivery and decay reach equilibrium within 2 minutes, producing a heterogeneous distribution that is proportional to the perfusibility of the tissue concerned and the time required to reach it. The ultrashort halflife of the radionuclide rapidly eliminates activity when delivery ceases; thus, experiments can be sequentially repeated at brief intervals. The radiation hazard for easily imaged doses is negligible. Preliminary studies in open chest dogs were visualized by scintillation camera, stored on digital data disk, processed, and displayed in dual channel, dual color mode on a video system. Images of myocardial perfusion defined relative levels of perfusion, collateral circulation between coronary arterial branches, equilibrium time of diffusible perfusion of the myocardium, focal defects in induced occlusion, collateral circulation to occlusion, and reactive hyperemia after release of induced coronary occlusion. The system and technique appear applicable to human subjects.