Effects of smoking reduction during pregnancy on the birth weight of term infants

This study was undertaken to determine 1) whether reducing tobacco exposure during pregnancy increases the birth weight of term infants and 2) the relative effects of early- and late-pregnancy exposure to tobacco on infant birth weight. Data were obtained from the Smoking Cessation in Pregnancy project, conducted in public clinics in three states (Colorado, Maryland, and Missouri) between 1987 and 1991. Self-reported cigarette use and urine cotinine concentration were collected from 1,583 pregnant smokers at study enrollment and in the third trimester. General linear models were used to generate mean adjusted birth weights for women who reduced their tobacco exposure by 50 percent or more and for those who did not change their exposure. Regression smoothing techniques were used to characterize the relation between birth weight and early exposure and birth weight and third-trimester exposure. Reducing cigarette use was associated with an increase in mean adjusted birth weight of only 32 g, which was not significant (p = 0.33). As third-trimester cigarette use increased, birth weight declined sharply but leveled off at more than eight cigarettes per day. Findings were similar when urine cotinine concentration was used. Women who smoke during pregnancy may need to reduce to low levels of exposure (less than eight cigarettes per day) to improve infant birth weight.

Why do women douche? Results from a qualitative study

OBJECTIVES

To explore women's attitudes and practices related to douching.

METHODS

We conducted focus groups between July and December 1999 with 34 black and 27 white women enrolled in a managed care plan in Memphis, Tennessee. Participants were at least 18 years of age and had douched at some time in their lives. Five groups were held with black women and five with white women.

RESULTS

The focus groups identified 13 themes that fell in four broad categories: general perceptions about feminine hygiene, douching behavior, factors perpetuating douching, and health information. Each of these categories is briefly discussed with supporting evidence.

CONCLUSIONS

First, women have deeply-rooted beliefs about the critical role of douching in making them feel clean. Second, douching generally starts at a young age and is reinforced by family, friends, and the media. Third, douching is a very difficult behavior to change; any efforts to influence this behavior must consider women's beliefs and the media marketing efforts that promote douching. Finally, simplistic interventions that only provide risk information about douching are not likely to result in behavior change.

Superior role of apolipoprotein B48 over apolipoprotein B100 in chylomicron assembly and fat absorption: an investigation of apobec-1 knock-out and wild-type mice

Editing of apolipoprotein (apo)-B100 mRNA to yield apo-B48 is a specific and developmentally regulated step in enterocytes of mammals. However, the functional significance of this step is not known. Since mice containing only apo-B100 have not been documented to exhibit any difference in intestinal fat absorption from wild-type mice, the evolutionary advantage of apoB mRNA editing has been questioned. In the present study, we have compared fat absorption and chylomicron assembly in apobec-1 knock-out (KO) or wild-type (WT) mice subjected to different dietary manipulations: low-fat chow, a fat-enriched 'Western' diet and overnight fasting. Experiments in vivo and in vitro revealed differences in the ability of KO and WT enterocytes to assemble and secrete chylomicrons under different dietary conditions. After overnight fasting, chylomicron secretion is reduced considerably in KO compared with WT enterocytes. This is not due to reduced synthesis of apo-B or triacylglycerol (TAG), but appears to be a result of impaired assembly of chylomicrons, so that triacylglycerol accumulates in the enterocytes. After feeding with fat, secretion of chylomicrons enriched in pre-existing TAG is stimulated in KO compared with WT mice. In the present study, we have documented for the first time that apo-B100 is considerably less efficient than apo-B48 in exerting its role in the early stage of chylomicron assembly, which is rate-limiting under conditions of low dietary fat. However, this impairment is overcome by increased TAG stores that stimulate later stages in assembly, which are rate-limiting in the fat-fed state. apo-B mRNA editing may result in more efficient fat absorption, specifically under conditions of food shortage or low-fat content, and thus provide an evolutionary advantage.

Measures of maternal tobacco exposure and infant birth weight at term

This study was undertaken to determine the relation between self-reported number of cigarettes smoked per day and urine cotinine concentration during pregnancy and to examine the relations between these two measures of tobacco exposure and birth weight. Data were obtained from the Smoking Cessation in Pregnancy project, conducted between 1987 and 1991. Cigarette smoking information and urine cotinine concentration were collected for 3,395 self-reported smokers who were receiving prenatal care at public clinics in three US states (Colorado, Maryland, and Missouri) and who delivered term infants. General linear models were used to quantify urine cotinine variability explained by the number of cigarettes smoked per day and to generate mean adjusted birth weights for women with different levels of tobacco exposure. Self-reported number of cigarettes smoked per day explained only 13.9% of the variability in urine cotinine concentration. Birth weight declined as tobacco exposure increased; however, the relation was not linear. The sharpest declines in birth weight occurred at low levels of exposure. Furthermore, urine cotinine concentration did not explain more variability in birth weight than did number of cigarettes smoked. These findings should be considered by researchers studying the effects of smoking reduction on birth outcomes.

Preventing Adverse Sequelae of Bacterial Vaginosis

BACKGROUND

The cause of bacterial vaginosis remains poorly understood. Recent evidence strengthens the association between bacterial vaginosis and serious medical complications.

GOAL

To review the evidence linking bacterial vaginosis with adverse pregnancy outcomes, complications after gynecologic procedures, and HIV infection, and to identify prevention strategies.

METHODS

In March 1999, the Centers for Disease Control and Prevention organized a conference to accomplish this goal.

RESULTS

Better understanding is needed concerning the etiology, epidemiology, and natural history of bacterial vaginosis. More efficacious treatment of bacterial vaginosis and strategies to reduce maternal complications associated with bacterial vaginosis, such as premature rupture of the fetal membranes, chorioamnionitis, premature labor and delivery, postdelivery endometritis, and postpartum infant complications should be developed. Recent evidence shows that screening and treatment of bacterial vaginosis before abortion reduces postabortion pelvic inflammatory disease, and that anaerobic coverage during hysterectomy reduces postoperative complications. Better understanding concerning the relation of bacterial vaginosis to acquisition of sexually transmitted diseases and HIV infection are needed as well as possible prevention strategies.

CONCLUSIONS

A national prevention effort should be guided by the results of research that addresses current knowledge gaps.

Are interpregnancy intervals between consecutive live births among black women associated with infant birth weight?

OBJECTIVES

The purpose of this study was to determine whether the length of interpregnancy intervals between consecutive live births among Black women had any significant effect on mean birth weight as had previously been reported in another study.

DESIGN

We examined a sample (1,048 women, 66% of study participants) from a study of non-Hispanic Black women whose infants were born at a large, inner-city, public hospital in Georgia from October 1988 through August 1990. Data were evaluated for the 494 women whose current and immediately previous pregnancies ended in the birth of a live infant weighing 500 grams or more.

METHODS

Linear regression and analysis of covariance models were developed.

RESULTS

The median interpregnancy interval was 15 months (range 1 to 207 months), with 19 (4%) of the women having intervals of less than 3 months. After adjustment for parity, gestational age (in weeks), and smoking status, the mean birth weight associated with an interpregnancy interval of three or more months was 3,106 grams, 215 grams greater than that for an interval of less than three months (P = .06).

CONCLUSIONS

Although longer birth spacing has been associated with certain positive social and health effects, the population attributable effect on infant birth weight may not be very significant.

Vaginal douching and preterm birth: an intriguing hypothesis

The rate of preterm birth has risen in recent years and is twice as high among black women as among white women. Neither the underlying causes nor the reasons for the racial disparity are clearly understood. Further, preventable risk factors have not been identified. We hypothesize that vaginal douching plays a key role in the risk of infection-related spontaneous preterm birth. Vaginal douching is a common behavior, twice as prevalent among black women as among white women. Douching may be an important mechanism by which vaginal pathogens gain access to the upper genital tract. Douching increases the risk of acquiring bacterial vaginosis. It may also facilitate the ascent of microorganisms into the upper genital tract, resulting in a chronic bacterial colonization inside the uterus. During pregnancy, the host inflammatory response is initiated, which stimulates preterm labor and birth. Douching, a potentially preventable risk factor, may explain a substantial proportion of the black-white disparity in preterm birth.

Unintended pregnancy among adult women exposed to abuse or household dysfunction during their childhood

CONTEXT

Studies have identified childhood sexual and physical abuse as a risk factor for adolescent pregnancy but the relationship between exposure to childhood abuse and unintended pregnancy in adulthood has, to our knowledge, not been studied.

OBJECTIVE

To assess whether unintended pregnancy during adulthood is associated with exposure to psychological, physical, or sexual abuse or household dysfunction during childhood.

DESIGN AND SETTING

Analysis of data from the Adverse Childhood Experiences Study, a survey mailed to members of a large health maintenance organization who visited a clinic in San Diego, Calif, between August and November 1995 and January and March 1996. The survey had a 63.4% response rate among the target population for this study.

PARTICIPANTS

A total of 1193 women aged 20 to 50 years whose first pregnancy occurred at or after age 20 years.

MAIN OUTCOME MEASURE

Risk of unintended first pregnancy by type of abuse (psychological, physical, or sexual abuse; peer sexual assault) and type of household dysfunction (physical abuse of mother by her partner, substance abuse by a household member, mental illness of a household member).

RESULTS

More than 45% of the women reported that their first pregnancy was unintended, and 65.8% reported exposure to 2 or more types of childhood abuse or household dysfunction. After adjustment for confounders (marital status at first pregnancy and age at first pregnancy), the strongest associations between childhood experiences and unintended first pregnancy included frequent psychological abuse (risk ratio [RR], 1.4; 95% confidence interval [CI], 1.2-1.6), frequent physical abuse of the mother by her partner (RR, 1.4; 95% CI, 1.1-1.7), and frequent physical abuse (RR, 1.5; 95% CI, 1.2-1.8). Women who experienced 4 or more types of abuse during their childhood were 1.5 times (95% CI, 1.2-1.8) more likely to have an unintended first pregnancy during adulthood than women who did not experience any abuse.

CONCLUSIONS

This study indicates that there may be a dose-response association between exposure to childhood abuse or household dysfunction and unintended first pregnancy in adulthood. Additional research is needed to fully understand the causal pathway of this association.

Dietary fish oils inhibit early events in the assembly of very low density lipoproteins and target apoB for degradation within the rough endoplasmic reticulum of hamster hepatocytes

Dietary fish oils inhibited secretion and stimulated intracellular degradation of apolipoprotein (apo)B in hamster hepatocytes, while dietary sunflower oils stimulated secretion and had no effect on degradation of apoB. To investigate the intracellular site at which fish oils act, we have made use of our previous observations that inhibition of degradation by N-acetyl-leucyl-leucyl-norleucinal (ALLN) results in accumulation of apoB in the trans -Golgi membrane and does not stimulate secretion, while inhibition of degradation by o-phenanthroline results in accumulation of apoB in the rough endoplasmic reticulum membrane and stimulates secretion. Thus, ALLN protects apoB which has been diverted from secretion and o -phenanthroline protects apoB which is targetted for secretion. Addition of o -phenantholine to the incubation medium of hepatocytes from fish oil-fed hamsters inhibited degradation of apoB and stimulated its secretion in particles of the density of VLDL, while addition of ALLN had no effect. These observations suggest that dietary fish oils reversibly inhibit early steps in the assembly of very low density lipoprotein precursors and target apoB for degradation in the rough endoplasmic reticulum.

The risk of low birth weight associated with vaginal douching

OBJECTIVE

To examine the association between vaginal douching and low birth weight (LBW) after accounting for known risk factors.

METHODS

We used cross-sectional interview data from the 1988 National Survey of Family Growth, a nationally representative sample of 4665 women of child-bearing age and 11,553 singleton live births. We compared the risk of LBW among women who reported they douched regularly with the risk among women who did not douche, after controlling for potential confounders including maternal age, race, household income, marital status, total number of pregnancies, smoking, alcohol use, drug use during the pregnancy, year of birth of each infant, geographic region, and self-reported history of pelvic inflammatory disease.

RESULTS

In multivariate analysis, regular douching was associated with an increased risk of LBW (adjusted odds ratio [OR], 1.29; 95% confidence interval [CI] 1.06, 1.57). Frequency of douching and LBW exhibited a dose-response. The adjusted OR for the association between daily douching and LBW was 2.49 (95% CI 1.23, 5.01) compared with an adjusted OR of 1.13 (95% CI 0.83, 1.55) for the association between monthly douching and LBW. There was no racial difference in the risk of LBW associated with douching.

CONCLUSION

These preliminary data suggest an association between douching and LBW risk. If these findings are replicated in future studies, douching may represent a major preventable risk factor for LBW.

Completeness of ascertainment of prenatal smoking using birth certificates and confidential questionnaires: variations by maternal attributes and infant birth weight. PRAMS Working Group. Pregnancy Risk Assessment Monitoring System

Birth certificate data frequently are used to monitor the prevalence of smoking during pregnancy. The authors used a two-sample capture-recapture method to estimate the completeness of ascertainment of prenatal smoking on birth certificates and on confidential questionnaires in six US states. Completeness of ascertainment was also examined according to maternal attributes and infant birth weight. The samples included white women who delivered a live infant between 1993 and 1995 in one of six states (Alabama, Alaska, Georgia, Maine, South Carolina, or West Virginia) and who responded to a questionnaire mailed to them 2-6 months postpartum as part of the Pregnancy Risk Assessment Monitoring System. State-specific sample sizes ranged from 2,647 to 4,795. The completeness of ascertainment ranged from 70.6% to 82.0% using birth certificates and from 86.2% to 90.3% using confidential questionnaires. In all six states, the birth certificates' completeness of ascertainment varied by maternal education and infant birth weight, and the questionnaires' completeness varied by maternal age. Both birth certificates and questionnaires underestimated the true extent of smoking during pregnancy among these white women. Differential reporting by birth weights recorded on birth certificates would result in an overestimated association between low birth weight and prenatal smoking.

Regulation of the assembly and secretion of very low density lipoproteins by the liver

Recent studies have suggested that there are three sites at which VLDL secretion by the liver may be controlled: (i) Newly synthesised apo-B either remains associated with the RER membrane and is degraded by the ubiquitin/proteasome system, or is translocated into the lumen and incorporated into lipid poor VLDL precursors; (ii) the lumenal apo-B is either degraded or moves on, and (iii) acquires the remaining VLDL lipids in the SER/cis-Golgi. Newly synthesised apo-B, at the cytosolic side of the RER, is stabilised and protected from degradation by the chaperone protein, hsp-70. Triacylglycerol, cholesterol ester and phospholipids have all been implicated in the translocation of apo-B and microsomal triglyceride protein plays a major role. If translocation does not occur then the apo-B is degraded. Dietary fish-oils, but not sunflower oil, inhibit movement of apo-B containing precursors from the RER and their assembly with lipids and target lumenal apo-B to degradation. This effect is reversed by inhibition of lumenal proteolysis, but not by inhibition of cytosolic proteolysis. Therefore lumenal degradation of apo-B and secretion appear to be in balance, so that if assembly of VLDL precursors is slowed, then degradation becomes predominant. If however, degradation is inhibited then VLDL assembly can proceed. These observations suggest that movement of VLDL precursors from the RER lumen to the second stage of assembly may be a further regulated step.

Cigarette smoking as a risk factor for ectopic pregnancy

OBJECTIVE

Our purpose was to assess the risk of ectopic pregnancy among women who smoke cigarettes.

STUDY DESIGN

We used data from a case-control study of ectopic pregnancy conducted from October 1988 to August 1990 at an inner-city hospital in Georgia. Cases were 196 non-Hispanic black women with a surgically confirmed ectopic pregnancy. Controls were non-Hispanic black women who had delivered either a live or a stillborn infant weighing at least 500 gm (n = 882) or who were pregnant and seeking an induced abortion (n = 237).

RESULTS

After we adjusted for parity, douching history, history of infertility, and age, the odds ratio for ectopic pregnancy was 1.9 (95% confidence interval 1.4 to 2.7) for women who smoked during the periconception period compared with women who did not smoke at that time. After stratification by the amount of daily smoking during the periconception period, the odds ratio rose from 1.6 (95% confidence interval 0.9 to 2.9) for women who smoked 1 to 5 cigarettes to 1.7 (95% confidence interval 1.1 to 2.8) for women who smoked 6 to 10 cigarettes to 2.3 (95% confidence interval 1.3 to 4.0) for women who smoked 11 to 20 cigarettes, and to 3.5 (95% confidence interval 1.4 to 8.6) for women who smoked >20 cigarettes per day.

CONCLUSION

In this inner-city population, cigarette smoking was an independent, dose-related risk factor for ectopic pregnancy among black women. The public health and medical care communities should inform the public of this additional risk associated with cigarette smoking and intensify intervention strategies to reduce cigarette smoking among women of reproductive age.

Multiple induced abortions as risk factor for ectopic pregnancy. A prospective study

OBJECTIVE

To assess the risk of ectopic pregnancy by the number of previous induced abortions.

DESIGN

Prospective cohort study.

METHODS

Three thousand seven hundred and fifty-four women, 39 years old or younger, living permanently in one Norwegian county, who had had at least one induced abortion between January 1, 1987 and December 31, 1992, at the University Hospital of Trondheim, Norway were followed prospectively for histologically verified ectopic pregnancies until December 31, 1993. Exposure time was measured from the most recent induced abortion (index abortion) until the ectopic pregnancy, closure date, or the subject's 40th birthday. Statistical analyses were done in SAS applying survival analyses and poisson regression.

RESULTS

During the follow-up period of 164,167 women-months, we observed 24 ectopic pregnancies in 3,754 women. The adjusted incidence density ratio (aIDR) for women who had had two or more induced abortions was 1.2 (95% CI: 0.5-3.1) in comparison with the reference group of women who had had one induced abortion. Measuring exposure as increasing number of consecutive induced abortions, no dose-response to ectopic pregnancy was found between two consecutive (aIDR 0.9) and three or more consecutive abortions (aIDR 1.1) in comparison with the reference group.

CONCLUSION

In our setting, no excess risk of ectopic pregnancy was associated with multiple previous induced abortions compared with one previous induced abortion.

Vaginal douching and the risk of ectopic pregnancy among black women

OBJECTIVE

Our goal was to determine whether vaginal douching was associated with ectopic pregnancy among black women and whether specific douching behaviors were associated with differences in risk.

STUDY DESIGN

We analyzed data from a case-control study of ectopic pregnancy conducted between October 1988 and August 1990 at a major public hospital in Atlanta, Georgia. Case subjects were 197 black women with surgically confirmed ectopic pregnancies; the control group included 882 black women who were delivered of live or stillborn infants and 237 black women who were seeking to terminate a pregnancy.

RESULTS

The adjusted odds ratio for ectopic pregnancy associated with ever having douched was 3.8 (95% confidence interval 1.6 to 8.9). The risk increased with increasing number of years of douching at least once per month. No douching behavior was found to be without risk; even women who douched for routine cleanliness were at increased risk of ectopic pregnancy.

CONCLUSIONS

Vaginal douching is a modifiable behavior that may greatly increase a woman's risk of ectopic pregnancy.

The relation between induced abortion and ectopic pregnancy

OBJECTIVE

To determine whether having had one or more induced abortions increases a woman's risk of having an ectopic pregnancy.

METHODS

We conducted a case-control study of all women admitted to a major metropolitan hospital in Georgia with a surgical diagnosis of ectopic pregnancy during the period of October 1988 to August 1990. Controls were randomly selected from women seeking an induced abortion or delivering an infant at the same hospital. After exclusions, this analysis included 182 cases and 1056 controls. Stratified analysis and unconditional logistic regression were used to control for confounding and to estimate the relative risks.

RESULTS

Approximately 90% of cases and controls were non-Hispanic, black women; 34% of the cases and 36% of the controls reported a history of induced abortion. The crude odds ratio for having an ectopic pregnancy associated with a history of induced abortion was 0.9 (95% confidence interval 0.6, 1.3). The odds ratio remained the same after adjusting for selected confounding variables and stratifying by the number of induced abortions, gestational age at the time of abortion, place where the abortion was performed, and the woman's report of medical complications of the abortion.

CONCLUSION

We found no evidence that having one or more induced abortions increases a woman's risk of having an ectopic pregnancy.

Investigation of the role of lipids in the assembly of very low density lipoproteins in rabbit hepatocytes

Our aims were i) to determine which lipids colocalize with newly synthesized apolipoprotein (apo) B in the lumen of the rough endoplasmic reticulum (RER), and thus may play a role in the stabilization and/or translocation of this protein; and ii) to determine the intracellular sites of assembly of lipids into very low density lipoprotein (VLDL). In order to do this, we have developed a new method for the separation of ER-derived microsomes on self-generated gradients of iodixanol. Rabbit liver microsomes were resolved into two broad peaks, the lighter peak contained smooth vesicles and the heavier peak contained rough vesicles. Each peak was collected in a number of subfractions. A single gradient thus separates the initial events in the secretion process (RER fractions), from later events (smooth endoplasmic reticulum (SER) fractions). The microsomal fractions were separated into membranes and lumenal contents, and the mass of apoB and VLDL lipids determined by ELISA or high performance thin-layer chromatography, respectively. The biosynthetic relationships of apoB and lipids were investigated, in timed or chase experiments, by incubation of isolated rabbit hepatocytes with radiolabeled precursors of apoB or lipids, followed by isolation and analysis of the microsomal fractions. The results indicate that very small amounts of triacylglycerol, cholesterol, and cholesteryl ester co-localize with apoB into the lumen of the RER. The bulk of the VLDL lipids were in the lumen of the SER. However, some newly synthesized triacyl-glycerol, phospholipid, cholesterol, and cholesteryl ester were also transferred to the lumen of the RER and were chased into the SER lumen. Double-labeling experiments showed that cholesteryl ester produced from newly synthesized cholesterol (labeled with [3H]mevalonate and [14C]oleate) was almost exclusively present in the RER, while cholesteryl ester in the SER was labeled only with [14C]oleate. Thus, distinct intracellular lipid-pools may be involved at different stages in the assembly of VLDL.

Increasing incidence of ectopic pregnancy in one Norwegian county--a population based study, 1970-1993

OBJECTIVE

To estimate time trends related to ectopic pregnancy while considering the contribution of repeat ectopic pregnancy and changing treatment for infertile couples over the past 24 years.

METHODS

Population based incidence data on ectopic pregnancy were collected from the only two hospitals in one Norwegian county from 1970 through 1993. Cases were identified through hospital discharge registries and all medical records were reviewed. Only females, aged 15-44 years, living permanently in the county and having a histologically verified ectopic pregnancy were eligible for the study. Data were analyzed in 5-year periods and 5-year age-groups.

RESULTS

The incidence of ectopic pregnancy (per 1,000 woman-years) increased fourfold from the first to the last period. When we restricted the analyses to women with no previous ectopic pregnancy and no previous infertility surgery or treatment, we observed a linear threefold increase in the number of ectopic pregnancies.

CONCLUSIONS

Repeat ectopic pregnancy and increased infertility treatment in the late 1970s and early 1980s might explain at most 25% of the increase in the incidence of ectopic pregnancy. After 1985, assisted reproduction might contribute to 4-5% of ectopic pregnancies diagnosed. The introduction of laparoscopy might explain some of this increase in the 1970s; however, we doubt that the introduction of more sensitive pregnancy tests or vaginal ultrasound in the 1980s contributed to the observed increase in ectopic pregnancy.

Women and smoking: an update for the 1990s

Cigarette smoking is associated with many health hazards, ranging from lung cancer to low infant birth weight. In the United States in 1994, 23.1% of all women and 14.6% of pregnant women smoked. Few physicians ask their patients about smoking, although minimal effort by physicians could help many smokers to quit. This article summarizes the current data on smoking prevalence, reviews quitting techniques, covers topics of particular interest to physicians caring for women, and suggests ways in which physicians may become more active in preventing smoking among teens.

Previous cesarean delivery and the risk of ectopic pregnancy

OBJECTIVE

To determine whether previous cesarean delivery is an independent risk factor for ectopic pregnancy.

METHODS

We analyzed data collected between October 1988 and August 1990 from a case-control study of ectopic pregnancy among parous, black, non-Hispanic women, 18-44 years old, at a major metropolitan hospital in Georgia. Cases were 138 women with confirmed ectopic pregnancy; controls were 842 women either seeking abortion or delivering an infant. Unconditional logistic regression was used to estimate the relative risk while controlling for the effects of potential confounders selected a priori.

RESULTS

Adjusted for age, parity, marital status, history of pelvic inflammatory disease, infertility, douching, and smoking, the odds ratio was 0.6 (95% confidence interval 0.4-1.1), indicating no significant association.

CONCLUSION

We found no evidence of an increased risk of ectopic pregnancy related to previous cesarean delivery.

Integrating smoking cessation into routine public prenatal care: the Smoking Cessation in Pregnancy project

OBJECTIVES

In 1986, the state health departments of Colorado, Maryland, and Missouri conducted a federally-funded demonstration project to increase smoking cessation among pregnant women receiving prenatal care and services from the Women, Infants, and Children (WIC) program in public clinics.

METHODS

Low-intensity interventions were designed to be integrated into routine prenatal care. Clinics were randomly assigned to intervention or control status; pregnant smokers filled out questionnaires and gave urine specimens at enrollment, in the eighth month of pregnancy, and postpartum. Urine cotinine concentrations were determined at CDC by enzyme-linked immunosorbent assay and were used to verify self-reported smoking status.

RESULTS

At the eighth month of pregnancy, self-reported quitting was higher for intervention clinics than control clinics in all three states. However, the cotinine-verified quit rates were not significantly different.

CONCLUSIONS

Biochemical verification of self-reported quitting is essential to the evaluation of smoking cessation interventions. Achieving changes in smoking behavior in pregnant women with low-intensity interventions is difficult.

A prospective study of childbearing and 10-year weight gain in US white women 25 to 45 years of age

Although birth rates to US women aged 25 and older have increased markedly over the last two decades, accurate estimates of the long-term weight gain associated with childbearing are not available for older mothers in the general population. We examined the effect of childbearing on weight change in 2547 white women aged 25-45 years who were initially weighed in the First National Health and Nutrition Examination Survey (1971-75) and who were reweighed an average of 10 years later. Linear and logistic regression estimates were adjusted for duration of follow-up, age, body mass index, initial parity, education, smoking, drinking, employment status, marital status, illness, physical activity, and dieting to lose weight. Compared to parous women who did not give birth during the study period, the mean excess weight gain was 1.6 kg (95% Confidence Limits, +/- 2.3 kg) for nulliparous women, and was 1.7 kg (+/- 1.1 kg), 1.7 kg (+/- 2.0 kg), and 2.2 kg (+/- 4.3 kg), for women having one, two and three live births, respectively. Among women who were nulliparous at baseline, those that had their live births during the study period gained similar amounts of weight to that of women who began childbearing before the beginning of the study. The risk of gaining more than 13 kg was increased by 40%-60%, and the risk of becoming overweight was increased by 60%-110% in women having live births during the study. We conclude that the average weight gain associated with childbearing after the age of 25 is quite modest in US white women. However, for some women who give birth after the age of 25 the risks of major weight gain and becoming overweight are increased in association wtih childbearing.

Pregnancy planning and pre-conception counseling. The PRAMS Working Group

OBJECTIVE

To estimate the percentage of women with one or more of four potentially modifiable risks who could have availed themselves of pre-conception counseling.

METHODS

We defined pre-conception counseling to be consultation that occurs shortly before a couple attempts conception. Thus, we assumed that to obtain pre-conception counseling, a woman must plan her pregnancy. We used data from a population-based survey of 12,452 new mothers in four states who delivered babies during 1988-1990. Mothers were contacted 3-6 months after delivery and asked about pre-conception behaviors and the planning status of their pregnancies. We estimated the percentage of women who planned their pregnancies and had an indication for pre-conception counseling related to smoking, drinking, being underweight, or delaying initiation of prenatal care.

RESULTS

State-specific response rates ranged from 68-84%. Sixty percent of mothers reported that their pregnancies were planned. In general, mothers with unintended pregnancies were more likely to have an indication for pre-conception counseling than mothers with planned pregnancies. Thirty-eight percent of all mothers planned their pregnancies and had one or more indications for pre-conception counseling. An additional 30% had one or more indications for counseling but did not have a planned pregnancy.

CONCLUSIONS

Despite the limited range of indications for counseling that we considered, a substantial percentage of women potentially could have used counseling. A similar percentage of women could have benefited from family planning services.

Smoking, pregnancy, and source of prenatal care: results from the Pregnancy Risk Assessment Monitoring System. The Pregnancy Risk Assessment Monitoring System Working Group

OBJECTIVE

To assess the impact of current smoking intervention efforts and to target future efforts by describing the relationships between maternal smoking, smoking cessation, and source of prenatal care.

METHODS

We used population-based data from 6319 mothers who delivered live-born infants during 1988 and 1989 in Maine, Michigan, Oklahoma, and West Virginia. The number of women sampled per state ranged from 1490-2659; state-specific response rates ranged from 66-84%. Analysis weights adjusted for selection probability and non-response.

RESULTS

The prevalences of maternal smoking before, during, and after pregnancy among women receiving publicly funded prenatal care were 2.3-3.4 times the comparable prevalences among privately insured women receiving prenatal care from private providers. Although many smokers reduced or quit smoking during pregnancy, most resumed or increased their smoking to nearly pre-pregnancy levels by 3-6 months postpartum.

CONCLUSIONS

Interventions should target the very high levels of smoking among the 27% of women receiving publicly funded prenatal care. However, from a population perspective, the greatest potential for reduction in smoking is among patients of private providers, who care for 61% of pre-pregnancy smokers.

Trends in obstetric operative procedures, 1980 to 1987

OBJECTIVES

Increasing rates of cesarean deliveries have received widespread attention in recent years, as concern in the United States about unnecessary surgical procedures has increased. However, little information has been published on the national trends of other operative obstetric procedures occurring during deliveries.

METHODS

We analyzed data from the National Hospital Discharge Survey to examine trends in the use of forceps, vacuum extraction, and cesarean section from 1980 through 1987.

RESULTS

The rate of cesarean sections increased by 48%, while the rate of forceps procedures declined by 43%. Although the risk of cesarean section was significantly increased for older women, the risk of forceps and vacuum extraction procedures did not vary by age. Women with private insurance were significantly more likely to receive a cesarean section (rate ratio [RR] = 1.2), forceps procedure (RR = 1.7), and vacuum extraction procedure (RR = 1.8) than were women without private insurance.

CONCLUSIONS

As pressure mounts to decrease the national cesarean section rate from 24% to 15% by the year 2000, attention should also be given to surveillance of other operative delivery procedures.

Hospitalization for pregnancy complications, United States, 1986 and 1987

OBJECTIVE

The purpose of our analysis was to provide a national overview of the magnitude of the public health burden associated with inpatient care for pregnancy complications.

STUDY DESIGN

We analyzed data from the National Hospital Discharge Survey for 1986 and 1987. We calculated ratios of hospitalizations for pregnancy complications for every 100 hospitalizations involving a birth. Standard errors for these ratios were calculated with RATIOEST, and relative ratios with 95% confidence intervals were calculated for subgroups of interest.

RESULTS

We found that for every 100 hospitalizations involving a birth, there were 22.2 nondelivery hospitalizations for pregnancy complications (14.6 antenatal complications, 7.6 pregnancy loss complications). These ratios were higher for black than for white women (relative ratio 1.4, 95% confidence interval 1.2 to 1.6). The effects of marital status, age, and insurance coverage differed between black and white women, and mean length of stay was longer for black than for white women.

CONCLUSION

Hospitalization for pregnancy complications is far more common than is widely appreciated and is more frequent among black than white women.

Smoking during pregnancy: prevalence, effects, and intervention strategies

Smoking prevalence rates have been declining in the United States, but an estimated 25 percent of pregnant women continue to smoke. Smoking during pregnancy is considered one of the leading, preventable causes of low birthweight. Research attributes 21 to 39 percent of low birthweight to smoking during pregnancy, although the exact mechanism of the effect is not completely understood. Several well-designed studies have shown that pregnant smokers are more likely to stop smoking if they are provided with systematic interventions. This overview describes adverse consequences, prevalence, possible mechanisms of action, and prenatal smoking-cessation programs that have proved effective. A five-step approach is outlined for clinicians who want to counsel their prenatal clients.

Trends in alcohol consumption by pregnant women. 1985 through 1988

To examine trends in alcohol consumption among pregnant women, we examined data collected from 21 states participating in the Behavioral Risk Factor Surveillance System for 4 consecutive years: 1985 through 1988. Overall, 429 (25%) of 1712 pregnant women and 19,903 (55%) of 36,057 nonpregnant women 18 to 45 years of age reported using alcohol in the previous month. Pregnant women who used any alcohol reported consuming a median of four drinks per month, whereas nonpregnant women who used any alcohol reported nine. The prevalence of alcohol consumption among pregnant women declined steadily, from 32% in 1985 to 20% in 1988, but the median number of drinks per month for pregnant women who drank did not change. No decline was observed among the less educated or those under the age of 25 years. In 1988, the prevalence of alcohol use among pregnant women remained highest among smokers (37%) and the unmarried (28%). Although the overall consumption of alcohol by pregnant women in the United States appears to be declining, special efforts are needed to reduce alcohol use among pregnant women who are smokers, unmarried, less educated, or younger, women who may already be at high risk of a poor pregnancy outcome.

Smoking before, during, and after pregnancy

We report the first national data on smoking before, during, and after pregnancy. Estimates are based on the 1986 Linked Telephone Survey that reinterviewed 1,550 White women 20-44 years of age who were respondents to the 1985 National Health Interview Survey. An estimated 39 percent of White women who had smoked before pregnancy quit smoking while pregnant (27 percent when they found out they were pregnant and 12 percent later during pregnancy). Women with less than 12 years of education were five times as likely to smoke and one-fourth as likely to quit as those with 16 or more years of education. Women who smoked more than one pack of cigarettes per day before pregnancy were one-fifth as likely to quit as those smoking less. Of the women who quit, 70 percent resumed smoking within one year of delivery. Of those who relapsed, 67 percent resumed smoking within three months of delivery and 93 percent within six months. There is little evidence of educational differentials in relapse rates. The fact that relapse remains high suggests that while health of the fetus is a strong influence on women's smoking habits, women may be less aware of the effect of passive smoke on the infant.

Outrunning the risks: a behavioral risk profile of runners

There is a need to assess better the relationship between physical activity and other health behaviors through population-based studies. Using the state-based Behavioral Risk Factor Surveillance System, we examined the behavioral risk factors of smoking, alcohol use, hypertension detection, obesity, seat-belt use, and physical activity in 2,412 runners and 26,538 nonrunners. Our analyses demonstrated marked differences in behavioral risk profiles between runners and nonrunners. Runners, regardless of the amount of running, were more likely to be nonsmokers, be of normal weight, be normotensive, and regularly use seat belts than were nonrunners of similar age and sex. Patterns of alcohol use were not different when comparing male runners with male nonrunners. However, female runners were more likely to drink and drive and to use alcohol on a chronic basis compared to their nonrunning counterparts. The "runner's lifestyle" may convey a certain level of protection from chronic disorders that are associated with these risk factors. However, further prospective studies are needed to examine in more detail the relationship of running to the risks and/or benefits for improved health.

Predicting lower-extremity injuries among habitual runners

This prospective study of 583 habitual runners used baseline information to examine the relationship of several suspected risk factors to the occurrence of running-related injuries of the lower extremities that were severe enough to affect running habits, cause a visit to a health professional, or require use of medication. During the 12-month follow-up period, 252 men (52%) and 48 women (49%) reported at least one such injury. The multiple logistic regression results identified that running 64.0 km (40 miles) or more per week was the most important predictor of injury for men during the follow-up period (odds ratio = 2.9). Risk also was associated with having had a previous injury in the past year (odds ratio = 2.7) and with having been a runner for less than 3 years (odds ratio = 2.2). These results suggest that the incidence of lower-extremity injuries is high for habitual runners, and that for those new to running or those who have been previously injured, reducing weekly distance is a reasonable preventive behavior.

The box plot: a simple visual method to interpret data

Exploratory data analysis involves the use of statistical techniques to identify patterns that may be hidden in a group of numbers. One of these techniques is the "box plot," which is used to visually summarize and compare groups of data. The box plot uses the median, the approximate quartiles, and the lowest and highest data points to convey the level, spread, and symmetry of a distribution of data values. It can also be easily refined to identify outlier data values and can be easily constructed by hand. We apply box plots to tabular data from two recently published articles to show how readers can use box plots to improve the interpretation of data in complex tables. The box plot, like other visual methods, is more than a substitute for a table: It is a tool that can improve our reasoning about quantitative information. We recommend that the box plot be used more frequently.

The Surgeon General's warnings in outdoor cigarette advertising. Are they readable?

Outdoor advertising media represent a major vehicle by which cigarette companies promote their products. We investigated the readability of the Surgeon General's warning in cigarette advertisements (ads) in two outdoor media: billboards and taxicab ads. In an experiment in metropolitan Atlanta under typical driving conditions, observers were able to read the entire health warning on 18 (46%) of 39 street billboards but on only two (5%) of 39 highway billboards. In contrast, the content of the ads (ie, brand name, other wording, and notable imagery) could be recognized under the same conditions on more than 95% of the billboards. In a similar study of 100 taxicab cigarette ads in New York City, observers were unable to read the health warning in any of the ads but were able to identify the brand name in all ads and notable imagery in 95% of the ads. Significant differences between the readability of the warning and identification of the advertising content persisted even when partially read warnings were considered to have been read. We conclude that the Surgeon General's warning is not readable in its current form in the vast majority of billboard and taxicab ads. Factors contributing to unreadability include the small size of the letters, the excessive length of the warnings, the distance between the viewers and the ads, and movement between the viewers and the ads.

Comparing the prevalence of smoking in pregnant and nonpregnant women, 1985 to 1986

The 1990 health objectives for the nation state that pregnant women should be only half as likely to smoke as nonpregnant women. To assess progress toward meeting this objective, we used cross-sectional data from the 26 states in the Behavioral Risk Factor Surveillance System in 1985 and 1986. We compared the prevalence of self-reported smoking among pregnant (N = 836) and nonpregnant (N = 18,025) women aged 18 to 45 years. Overall, pregnant women were 70% as likely to be current smokers as nonpregnant women (prevalence ratio, 0.7; 95% confidence interval, 0.6 to 0.8), while blacks showed the largest pregnancy-associated reduction in the prevalence of smoking (prevalence ratio, 0.5; 95% confidence interval, 0.3 to 0.9). Most of the difference in smoking prevalence occurred not because pregnant women were less likely to have ever smoked, but because pregnant women were more likely to have quit smoking than nonpregnant women. However, unmarried pregnant white women were 40% more likely to smoke than their nonpregnant counterparts (prevalence ratio, 1.4; 95% confidence interval, 1.1 to 1.7). We conclude from this analysis that the 1990 health objective for smoking among pregnant women is unlikely to be achieved. Clinicians providing care to pregnant women need to pay increased attention to smoking cessation.

Smoking by blacks and whites: socioeconomic and demographic differences

Using data from the 1985 National Health Interview Survey for persons aged 25-64 years, we controlled simultaneously for socioeconomic status (SES), demographic factors, and race in multivariate logistic regression analyses. We found that the odds of ever smoking are not higher for Blacks compared with Whites, when the other variables are controlled. By contrast, the odds of heavy smoking for Blacks are far less than for Whites, while Blacks are significantly less likely than Whites to quit smoking regardless of SES or demographic factors. Smoking cessation and prevention programs must be planned with these behavioral, SES, and demographic differences in mind.

Unintended laparotomy associated with laparoscopic tubal sterilization

Although the complication rate for laparoscopic tubal sterilization is generally low, laparotomy is sometimes necessary to complete the sterilization or manage complications. To better characterize factors that predispose women to unintended laparotomy, we analyzed data from the Collaborative Review of Sterilization. Of the 5027 women undergoing laparoscopic tubal sterilization, 12 had unintended laparotomies to manage complications, whereas 39 women had unintended laparotomies because of technical inability to complete the laparoscopic procedure. Women with prior abdominal or pelvic surgery had an increased risk of unintended laparotomy (relative risk = 10.2, 95% confidence interval = 5.3 to 19.7). Women with a history of intrauterine device use or pelvic inflammatory disease had elevated risks that were not statistically significant (relative risk = 2.2 and 1.5, respectively). Comparative studies of alternative surgical approaches for tubal sterilization are needed to formulate recommendations for women who may be at increased risk of unintended laparotomy associated with the laparoscopic approach.

The relative impact of smoking and oral contraceptive use on women in the United States

Women who smoke and use oral contraceptives (OCs) are at increased risk for cardiovascular and cerebrovascular disease. To study the prevalence of smoking and OC use and other behaviors affecting health, 28 states and the District of Columbia conducted telephone surveys during 1981 through 1983. More than 22,000 US adults were interviewed, of whom 5779 women aged 18 to 44 years were studied. Data were weighted to represent the US population. Overall, 7.4% of US women aged 18 to 44 years reported smoking and using OCs; 1.1% reported smoking 25 or more cigarettes per day while using OCs. Although women aged 18 to 24 years were most likely to smoke and use OCs, combined smoking and OC use contributed substantially to the number of excess cases of myocardial infarctions occurring among US women aged 35 to 44 years. However, regardless of OC use, smoking accounted for most of the excess cases. Therefore, health care providers need to intensify their efforts to reduce smoking among their patients.

Community-based exercise intervention: Zuni Diabetes Project

Non-insulin-dependent diabetes mellitus (NIDDM) is a serious health problem among the Zuni Indians of New Mexico. In July 1983, Indian Health Service personnel initiated a community-based exercise program designed to help control NIDDM in the community. To retrospectively evaluate the effects of the exercise program, the medical records of 30 participants with NIDDM were compared with the medical records of 56 nonparticipants with NIDDM matched by age, sex, health-care provider, and duration of NIDDM. From 1 July 1983 through 1 October 1985, participants had a mean weight loss of 4 kg, whereas nonparticipants had a mean weight loss of 0.9 kg (P less than .05). Participants' fasting blood glucose values dropped by a mean of 43 mg/dl, compared to a mean drop of 2 mg/dl among the nonparticipants (P less than .05). Participants were significantly more likely than nonparticipants to have stopped their hypoglycemic medication (relative risk 4.2) and to have decreased their medication dosage (relative risk 2.2). These results suggest that participation in a community-based exercise program can produce significant weight loss and improvement in glycemic control among a group of Native Americans with NIDDM.

Cigarette smoking and the risk of epithelial ovarian cancer

Cigarette smoking may affect each of the currently proposed mechanisms of ovarian carcinogenesis. Whether cigarette smoking has any effect on the development of ovarian cancer has not been adequately evaluated. To study this issue, the authors examined data from the Cancer and Steroid Hormone Study, a multicenter, case-control study of gynecologic cancers conducted between December 1, 1980, and December 31, 1982, in eight geographic areas of the United States. This analysis utilized data on 494 women with newly diagnosed epithelial ovarian cancer and 4,238 population-based control women 20-54 years of age. There was no association of epithelial ovarian cancer with dose of cigarette smoking, age smoking started, time since smoking started, or time since smoking last occurred. Simultaneous adjustment for age, parity, history of oral contraceptive use, and other potentially confounding factors did not alter these results.

Physical activity and the incidence of coronary heart disease

Our review focuses on all articles in the English language that provide sufficient data to calculate a relative risk or odds ratio for CHD at different levels of physical activity. The inverse association between physical activity and incidence of CHD is consistently observed, especially in the better designed studies; this association is appropriately sequenced, biologically graded, plausible, and coherent with existing knowledge. Therefore, the observations reported in the literature support the inference that physical activity is inversely and causally related to the incidence of CHD. The two most important observations in this review are, first, better studies have been more likely than poorer studies to report an inverse association between physical activity and the incidence of CHD and, second, the relative risk of inactivity appears to be similar in magnitude to that of hypertension, hypercholesterolemia, and smoking. These observations suggest that in CHD prevention programs, regular physical activity should be promoted as vigorously as blood pressure control, dietary modification to lower serum cholesterol, and smoking cessation. Given the large proportion of sedentary persons in the United States (91), the incidence of CHD attributable to insufficient physical activity is likely to be surprisingly large. Therefore, public policy that encourages regular physical activity should be pursued.

Postmenopausal smoking, estrogen replacement therapy, and the risk of endometrial cancer

Previous studies of the association between cigarette smoking and endometrial cancer have yielded inconsistent results. There is some evidence that this discrepancy may be explained by differences in menopausal status between the groups of women studied. We addressed the issue of the effects of postmenopausal smoking on endometrial cancer risk using data from the Cancer and Steroid Hormone Study, a multicenter, population-based, case-control study of gynecologic cancers in the United States. We found that smoking after natural menopause is associated with a 70% reduced risk of endometrial cancer among estrogen users and a 50% reduced risk among nonusers of estrogen. These findings are consistent with previously proposed biologic effects of smoking on estrogen metabolism, which may have important clinical implications.

Vasectomies performed by private physicians, United States, 1980 to 1984

Using data from the National Disease and Therapeutic Index, we estimated that between 1980 and 1984, 1.9 X 10(6) U.S. men had vasectomies. Men between the ages of 30 and 39 years, and white men, were more likely than others to undergo the procedure. Further national data on this popular procedure are needed.

Characteristics of vasectomies performed in selected outpatient facilities in the United States, 1980

In 1981 the American Association of Gynecologic Laparoscopists and the Division of Reproductive Health, Centers for Disease Control, jointly conducted a study of vasectomies performed in outpatient facilities in 1980 in the United States. One hundred twenty-nine facilities that responded to either a mailed questionnaire or a telephone interview stated that vasectomies were performed there in 1980. The average cost was $273, with a range of $50-1,000. Facilities differed markedly in the use of anesthesia. Freestanding surgical centers reported the use of general anesthesia for 29% of the vasectomies. Other types of facilities were more likely to use local or regional anesthesia. Our data suggest areas for further research to improve the availability and safety of vasectomy.

Hysterectomy performed within 1 year after tubal sterilization

In the United States, approximately 650,000 women of reproductive age undergo tubal sterilization each year and some of these women later have hysterectomies. Little is known about risk factors for having hysterectomy after tubal sterilization. For examination of this issue, we analyzed data from the Collaborative Review of Sterilization, an ongoing multicenter prospective study designed to assess the safety and efficacy of female sterilization operations. In 1979 and 1980, 4002 women 15 to 44 years of age had interval tubal sterilization; of these women, 64 had hysterectomies within 15 months, which yielded a cumulative incidence of 1.6%. Women with a history of menstrual complaints, leiomyomata, ovarian cysts, or endometriosis before their tubal sterilization had an increased risk of hysterectomy, compared with women without such a history. However, 98% of women with a history of these conditions did not have a hysterectomy within 15 months after tubal sterilization. Further follow-up of these women should help to better delineate their long-term risks.