Endotypes of difficult-to-control asthma in inner-city African American children.

African Americans have higher rates of asthma prevalence, morbidity, and mortality in comparison with other racial groups. We sought to characterize endotypes of childhood asthma severity in African American patients in an inner-city pediatric asthma population. Baseline blood neutrophils, blood eosinophils, and 38 serum cytokine levels were measured in a sample of 235 asthmatic children (6-17 years) enrolled in the NIAID (National Institute of Allergy and Infectious Diseases)-sponsored Asthma Phenotypes in the Inner City (APIC) study (ICAC (Inner City Asthma Consortium)-19). Cytokines were quantified using a MILLIPLEX panel and analyzed on a Luminex analyzer. Patients were classified as Easy-to-Control or Difficult-to-Control based on the required dose of controller medications over one year of prospective management. A multivariate variable selection procedure was used to select cytokines associated with Difficult-to-Control versus Easy-to-Control asthma, adjusting for age, sex, blood eosinophils, and blood neutrophils. In inner-city African American children, 12 cytokines were significant predictors of Difficult-to-Control asthma (n = 235). CXCL-1, IL-5, IL-8, and IL-17A were positively associated with Difficult-to-Control asthma, while IL-4 and IL-13 were positively associated with Easy-to-Control asthma. Using likelihood ratio testing, it was observed that in addition to blood eosinophils and neutrophils, serum cytokines improved the fit of the model. In an inner-city pediatric population, serum cytokines significantly contributed to the definition of Difficult-to-Control asthma endotypes in African American children. Mixed responses characterized by TH2 (IL-5) and TH17-associated cytokines were associated with Difficult-to-Control asthma. Collectively, these data may contribute to risk stratification of Difficult-to-Control asthma in the African American population.

Circulating TSLP associates with decreased wheezing in non-atopic preschool children: data from the URECA birth cohort.

BACKGROUND: Mouse models of atopic march suggest that systemic, skin-derived thymic stromal lymphopoietin (TSLP) mediates progression from eczema to asthma. OBJECTIVE: We investigated whether circulating TSLP is associated with eczema, allergic sensitization, or recurrent wheezing in young children. METHODS: A prospective analysis of the relationship between plasma levels of TSLP to allergic sensitization and recurrent wheezing was conducted in the birth cohort from the Urban Environment and Childhood Asthma (URECA) study. Plasma TSLP levels were measured at 1, 2, and 3 years of age and analysed for correlation with clinical parameters in each of the three years. Only those children with consecutive samples for all three years were included in this analysis. RESULTS: We detected TSLP in 33% of 236 children for whom plasma samples were available for all three years. Overall, a consistently significant association was not found between TSLP and eczema or allergic sensitization. With regard to recurrent wheezing, children with detectable TSLP at one year of age were significantly less likely to experience recurrent wheezing by 3 years compared with those children without detectable TSLP, but this was only seen in children without aeroallergen sensitization at 3 years (P < 0.01). CONCLUSIONS AND CLINICAL RELEVANCE: Contrary to our expectations, circulating TSLP was not significantly associated with eczema, allergen sensitization, or recurrent wheezing during the first three years of life. Early presence of circulating TSLP was significantly associated with reduced incidence of recurrent wheeze in those children not sensitized to aeroallergen. These findings suggest a possible underlying distinction between pathogenesis of developing atopic vs. non-atopic recurrent wheeze.

Longitudinal relationship of early life immunomodulatory T cell phenotype and function to development of allergic sensitization in an urban cohort.

BACKGROUND: Immunomodulatory T cells are thought to influence development of allergy and asthma, but early life longitudinal data on their phenotype and function are lacking. OBJECTIVES: As part of the Urban Environment and Childhood Asthma (URECA) study, we investigated the development of immunomodulatory T cell phenotype and function, and characterized their relation to allergic disease progression from birth through to 2 years of age. METHODS: Immunomodulatory T cell phenotype and function in cord blood mononuclear cells (CBMC) and peripheral blood mononuclear cells (PBMC) at 1 and 2 years of age were characterized by analysing CD25(bright) and FoxP3(+) expression, proliferative responses and cytokine production. The relation of immunomodulatory T cell characteristics to allergic sensitization and disease at 1- and 2-years of age was investigated. RESULTS: The proportion of CD4(+)CD25(bright) and CD4(+)CD25(+)FoxP3(+)T cells (n = 114, 83, 82 at birth, 1- and 2-years respectively) increased significantly, whereas there were no significant changes in the suppressive function of CD25(+)T cells (n = 78, 71, 81 at birth, 1- and 2-years respectively). Birth immunomodulatory T cell characteristics were not related to subsequent allergic sensitization or disease. However, increases in the numbers of CD4(+)CD25(bright) cells and their ability to suppress lymphoproliferative responses at 1 year of age were associated with reduced allergic sensitization at 1 (P = 0.03) and 2 (P = 0.02) years of age. Production of the anti-inflammatory cytokine IL-10 by CD25(+)T cells appeared to mediate this protective suppressive function. In contrast, by 2 years of age, we observed the emergence of a positive association of CD4(+)CD25(+) FoxP3(+) T cell numbers with allergic sensitization (P = 0.05) and eczema (P = 0.02). CONCLUSIONS AND CLINICAL RELEVANCE: These findings suggest that the relationship between immunomodulatory T cell subsets, allergic sensitization and eczema is developmentally regulated. In the first year of life, CD4(+)CD25(+) IL-10 producing T cells are associated with a reduced incidence of allergic sensitization. Once allergic sensitization or eczema is established, CD4(+)CD25(+)FoxP3(+)T-reg cells expand to potentially counteract the allergic inflammatory response. Understanding the relationship between development of immunoregulatory T cells and early onset atopy could lead to new preventive strategies for allergic diseases.

Allergen-specific IgE as a biomarker of exposure plus sensitization in inner-city adolescents with asthma.

BACKGROUND: Relationships among allergen-specific IgE levels, allergen exposure and asthma severity are poorly understood since sensitization has previously been evaluated as a dichotomous, rather than continuous characteristic. METHODS: Five hundred and forty-six inner-city adolescents enrolled in the Asthma Control Evaluation study underwent exhaled nitric oxide (FE(NO)) measurement, lung function testing, and completion of a questionnaire. Allergen-specific IgE levels and blood eosinophils were quantified. Dust samples were collected from the participants' bedrooms for quantification of allergen concentrations. Participants were followed for 12 months and clinical outcomes were tracked. RESULTS: Among sensitized participants, allergen-specific IgE levels were correlated with the corresponding settled dust allergen levels for cockroach, dust mite, and mouse (r = 0.38, 0.34, 0.19, respectively; P < 0.0001 for cockroach and dust mite and P = 0.03 for mouse), but not cat (r = -0.02, P = 0.71). Higher cockroach-, mite-, mouse-, and cat-specific IgE levels were associated with higher FE(NO) concentrations, poorer lung function, and higher blood eosinophils. Higher cat, dust mite, and mouse allergen-specific IgE levels were also associated with an increasing risk of exacerbations or hospitalization. CONCLUSIONS: Allergen-specific IgE levels were correlated with allergen exposure among sensitized participants, except for cat. Allergen-specific IgE levels were also associated with more severe asthma across a range of clinical and biologic markers. Adjusting for exposure did not provide additional predictive value, suggesting that higher allergen-specific IgE levels may be indicative of both higher exposure and a greater degree of sensitization, which in turn may result in greater asthma severity.

Effect of environmental allergen sensitization on asthma morbidity in inner-city asthmatic children.

BACKGROUND: Asthma causes significant morbidity in children, and studies have demonstrated that environmental allergies contribute to increased asthma morbidity. OBJECTIVE: We investigated the differences between allergen skin tests and specific IgE (SIgE) and the role of IgG in regards to allergen exposure levels, and asthma morbidity in inner-city children. METHODS: Five hundred and six serum samples from the National Cooperative Inner City Asthma Study (NCICAS) were evaluated for SIgE to cockroach (Blattella germanica), dust mite (Dermatophagoides farinae), and Alternaria as well as specific IgG (SIgG) and IgG(4) to cockroach (B. germanica) and total IgE levels. Associations between sensitization to these allergens, exposures, and asthma morbidity were determined. RESULTS: Sensitization to environmental allergens and total IgE correlated with increased health care and medication use, but not with symptoms of wheeze. Sensitization with exposure to cockroach was associated with increased asthma morbidity, whereas dust mite sensitization was correlated with asthma morbidity independent of exposure. There was also a strong correlation between SIgE levels and skin test results, but the tests did not always agree. The relationship between SIgE and asthma morbidity is linear with no obvious cutoff value. Increased Bla g 1 in the home was a good predictor for sensitization; however, this relationship was not demonstrated for Der f 1. Cockroach SIgG correlated with increased health care use, however, there was no modifying effect of SIgG or SIgG(4) on the association between cockroach SIgE and asthma morbidity. CONCLUSIONS: SIgE levels and skin prick test results to environmental allergens can serve as markers of severe asthma for inner-city children. Asthma morbidity increased in a linear manner with SIgE levels. IgG was not an important predictor or modifier of asthma morbidity.

Estimates of the risk of cardiovascular death attributable to low-dose oral contraceptives in the United States.

OBJECTIVE: Our purpose was to estimate the annual risk of death in the United States from cardiovascular disease attributable to low-dose combination oral contraceptives. STUDY DESIGN: Estimates of the risk of death from cardiovascular disease attributable to low-dose oral contraceptives were modeled on data from studies published through 1997 and from age-specific mortality rates in the United States for 1993 and 1994. RESULTS: Attributable risk of death from cardiovascular disease resulting from oral contraceptive use is 0.06 and 3.0 per 100,000 nonsmokers 15 to 34 years of age and 35 to 44 years of age, respectively. In smokers this risk increases, respectively, to 1.73 and 19.4 per 100,000 users in these 2 age groups; however, 97% and 85% of this risk is due to the combined effects of smoking and using oral contraceptives. The attributable risk of death from cardiovascular disease in nonsmoking oral contraceptive users is lower than the risk of death from pregnancy in nonusers of oral contraceptives at all ages; however, among smoking oral contraceptive users more than 35 years of age, the excess risk of death from oral contraceptives is higher than the risk of death from pregnancy. CONCLUSION: There is virtually no excess attributable risk of death from cardiovascular disease related to oral contraceptive use in young women. However, smokers more than 35 years of age should use a nonestrogen contraceptive.

PIP: The annual risk of death in the US from cardiovascular disease attributable to low-dose combination oral contraceptives (OCs) was estimated through use of data from studies published in 1980-1997 and from age-specific mortality rates for 1993 and 1994. Four cardiovascular disease categories were included: myocardial infarction, venous thromboembolism and pulmonary embolism, ischemic stroke, and hemorrhagic stroke. The overall risk of death from cardiovascular disease among nonsmoking users of low-dose OCs is 0.06/100,000 women in the 15-34 year age group and 3.03/100,000 women in the 35-44 year age group. For young nonsmokers, the excess mortality risk associated with OC use is smaller than the risk of death from pregnancy, whether terminated by abortion or carried to term. Among OC users who smoke, the risk of cardiovascular mortality is 1.73/100,000 in 15-34 year olds and 19.4/100,000 in women 35-44 years old; however, 97% and 85% of this risk, respectively, is composed of the combined OC-smoking risk. Among smoking OC users over 35 years of age, the excess risk of death from OCs exceeds the risk of death from pregnancy. Young nonsmokers raise their risk of death from cardiovascular disease by less than 10% (0.60-0.65/100,000) by using OCs, while young women who do not use OCs increase their risk of death by 260% (0.60-1.57/100,000) by smoking cigarettes. For older women, the corresponding increases are 95% among nonsmoking OC users and 315% among smoking nonusers. These estimates indicate that women over 35 years of age who smoke should not be permitted to use either low- or high-dose OCs because of the excess attributable risk of death from cardiovascular disease.

Views of Cameroonian sex workers on a woman-controlled method of contraception and disease protection.

Five hundred and twenty female Cameroonian sex workers participating in a clinical trial of the effectiveness of nonoxynol-9 (N-9) contraceptive film to prevent HIV infection were interviewed to determine their experience with this woman-controlled method. The sex workers liked the film, with over 80% stating they would continue to use it if it were shown to be effective against HIV and were to become widely available. However, they were much more likely to use condoms and films simultaneously with their clients (40%) than with their regular partners (16%). The advantages ascribed to the film were that its use was under the woman's control; it could be used without the partner's knowledge; it allowed direct contact between partners; and it provided back-up protection in case of condom breakage. Data from this small study suggest that development of an effective, woman-controlled method of pregnancy and disease protection would be welcomed by these women.

PIP: Nonoxynol-9 (N-9) vaginal contraceptive film, a square that dissolves quickly and easily in the vagina and may be used without the partner's knowledge, represents a potential woman-controlled method of contraception and sexually transmitted disease (STD) prevention. 520 of 1292 Cameroonian sex workers, enrolled in a clinical trial of the capability of N-9 contraceptive film to prevent HIV transmission, were interviewed about their experiences with this method. The clinical trial failed to demonstrate an additional protective effect of N-9 film against HIV or other STDs when used with a condom. During the study period, 50% of participants reported they always used a condom and 45% always used the film. 59% of those who did not always use a condom claimed it was because clients or partners objected. In contrast, only 15% of women who sometimes did not use the film cited partner objection. Over 80% of sex workers indicated they would use N-9 film with both clients and regular partners if it were shown to be effective and were available. With a regular partner, 66.5% would use the film alone and 15.6% would also use a condom. With clients, 46.5% would use the film alone and 39.8% the film and condom together. Sex workers liked the fact that the method was under the woman's control, could be used without the male partner's knowledge or agreement, allows direct contact between partners, and provides back-up protection in the event of condom breakage. These findings suggest a woman-controlled method, such as a vaginal film, with demonstrated safety and effectiveness, would be readily accepted by sex workers in Cameroon.

Users' understanding of the lactational amenorrhea method and the occurrence of pregnancy.

It is unknown whether a user's understanding of the Lactational Amenorrhea Method (LAM) is related to its successful use. A study of 876 LAM users in Pakistan and the Philippines collected information about women's understanding of LAM. The present analysis aims to determine: (1) the proportion of LAM users who understand the method, (2) whether any known factors can distinguish those who understand LAM from those who do not, and (3) whether an understanding of LAM is related to subsequent pregnancy. Over 75% of LAM users could consistently recite the LAM guidelines correctly for a full year postpartum. However, 38% of users failed to display, at least once, an understanding of LAM during the first year postpartum mainly by failing to abstain, to use another method or to explain their nonuse of another method when their LAM protection expired. LAM understanding generally could not be predicted by sociodemographic factors. The occurrence of pregnancy during the first year postpartum was not related to LAM understanding, regardless of how LAM understanding was defined, nor could it be predicted by any other measured characteristic of the users.

PIP: This study aims to determine 1) the proportion of lactational amenorrhea method (LAM) users who understand the method; 2) whether any known factors can distinguish those who understand LAM from those who do not; and 3) whether an understanding of LAM is related to subsequent pregnancy. Data were collected from 876 LAM users in Pakistan and the Philippines. It was found that 75% of LAM users could consistently recite the LAM guidelines correctly for a full year postpartum. However, 38% of users failed to display, at least once, an understanding of LAM during the first year postpartum mainly by failing to abstain, to use another method or to explain their nonuse of another method when their LAM protection expired. Also, the sociodemographic factors could not predict the level of understanding of LAM users. Therefore, the occurrence of pregnancy during the first year postpartum was not related to LAM understanding, regardless of how LAM understanding was defined, nor could it be predicted by any other measured characteristics of the users.

Maternal employment and breast-feeding: findings from the 1988 National Maternal and Infant Health Survey.

OBJECTIVES: This analysis uses nationally representative data from the 1988 National Maternal and Infant Health Survey to explore the factors, including employment, associated with breast-feeding initiation and duration. METHODS: Multiple logistic regression was used to model the determinants of breast-feeding initiation among 9087 US women. Multiple linear regression was used to model the duration of breast-feeding among women who breast-fed. RESULTS: Fifty-three percent of mothers initiated breast-feeding in 1988, and the decision to breast-feed was not associated with maternal employment. However, among breast-feeders, returning to work within a year of delivery was associated with a shorter duration of breast-feeding when other factors were controlled. Among employed mothers, the duration of maternity leave was positively associated with the duration of breast-feeding. CONCLUSIONS: The low rates of breast-feeding initiation in the United States are not attributable to maternal participation in the labor force. However, returning to work is associated with earlier weaning among women who breast-feed.

A comparison of two U.S. surveys of infant feeding.

This study compares the 1988 National Maternal and Infant Health Survey (NMIHS) and the 1989 Ross Laboratories Mothers Survey with respect to sample characteristics and proportions of women who breastfed. Weighted proportions of women included in the two surveys were compared according to various characteristics to see how well they represented U.S. childbearing women. A z-statistic was produced to test for significant differences in the proportions who breastfed. In 1988-89, 52.2% of American women breastfed according to the Ross survey and 53.4% according to the NMIHS. Despite differences in sample size, sampling technique and the application of sample weights, the difference between the surveys was only 1 percentage point, and most levels of most variables examined were comparable. The Ross survey is a valuable source of data because it is ongoing, and it is generally corroborated by the NMIHS. The NMIHS is probably more representative of the U.S. population of childbearing women, and is a reliable source of data for setting U.S. objectives concerning infant feeding, and for the study of other issues vis-à-vis breastfeeding.

The duration and character of postpartum bleeding among breast-feeding women.

OBJECTIVE: To examine the postpartum bleeding experience of a cohort of breast-feeding women and to compare it with the conventional definition of lochia. METHODS: Four hundred seventy-seven experienced breast-feeding women in Manila, the Philippines, were followed prospectively from delivery and recorded vaginal bleeding in a menstrual diary. The median duration of lochia was calculated using survival analysis. In addition, all bleeding separate from lochia within the first 8 weeks postpartum was noted. RESULTS: The median duration of lochia was 27 days and did not vary by age, parity, sex or weight of the infant, breast-feeding frequency, or level of supplementation. More than one-fourth of the women experienced a bleeding episode separated from the original lochial flow by at least 4 bleeding-free days and beginning no later than postpartum day 56. Ten breast-feeding women may have had their first menstrual bleed before day 56. CONCLUSIONS: Lochia lasted substantially longer than the conventional assumption of 2 weeks. It was common for postpartum bleeding to stop and start again or to be characterized by intermittent spotting or bleeding. Return of menses is rare among fully breast-feeding women in the first 8 weeks postpartum.

Fertility of fully breast-feeding women in the early postpartum period.

OBJECTIVE: To examine bleeding between 6 and 8 weeks postpartum in fully breast-feeding women and its association with fertility as assessed by hormone analysis. METHODS: Seventy-two fully breast-feeding women were followed prospectively from 42 days postpartum. Vaginal bleeding was recorded daily. Women who experienced bleeding were compared with women who did not with respect to time of ovulation and time of first menses. RESULTS: Nearly half of the women experienced some vaginal bleeding or spotting between 6 and 8 weeks postpartum. These women eventually menstruated and ovulated earlier than the women who did not bleed, but the differences were not significant. The study had 34% and 45% power to detect a 20% difference in the proportion menstruating and ovulating, respectively, at 6 months postpartum, and 10% and 16% power to detect the same differences at 1 year. Seven women experienced ovarian follicular development before day 56, but neither bleeding nor follicular development was associated with ovulation in any woman in the first 8 weeks postpartum. CONCLUSIONS: It is unlikely that vaginal bleeding in fully breast-feeding women in the first 8 weeks postpartum represents a return to fertility.

The frequency of coitus during breastfeeding.

BACKGROUND: New mothers and clinicians would benefit from an understanding of typical sexual behavior during breastfeeding. Unfortunately, little information is available about both the typical length of time to resumption of coitus and the frequency of sexual relations during breastfeeding. This paper describes the commencement and frequency of coitus among breastfeeding women in a variety of settings. METHODS: The analysis draws on data from two separate research studies. The first was undertaken in three sites (Birmingham, United Kingdom; Montreal, Canada; Sydney, Australia), the purpose of which was to correlate natural observations of fertility with the underlying hormonal profile among breastfeeding women using the symptom-thermal method of natural family planning. The second was a clinical trial of the lactational amenorrhea method of family planning conducted in Manila, the Philippines. RESULTS: Coital frequency reported by these populations of breastfeeding women appears to be lower than that reported in other studies for married women in general. As other research demonstrated, we found coital frequency and postpartum resumption of coitus to be associated with age, but not with the number of children in the household. CONCLUSIONS: A better understanding of the level of sexual activity among breastfeeding women could inform and improve programs that offer postpartum support and counseling about family planning.

Effectiveness of lactational amenorrhoea in prevention of pregnancy in Manila, the Philippines: non-comparative prospective trail.

OBJECTIVE: To determine the contraceptive efficacy of the lactational amenorrhoea method. DESIGN: Non-comparative prospective trial. SETTING: Urban Manila, the Philippines. SUBJECTS: 485 lower income, educated women with extensive experience of breast feeding. INTERVENTION: Women were offered all available contraceptives for use after birth. Those who chose the lactational amenorrhoea method were taught the method, screened for the study, and followed for 12 months to determine the risk of pregnancy when the method was used. MAIN OUTCOME MEASURES: Life table pregnancy rates during correct and incorrect use of the method, censored monthly in the event of sexual abstinence or the use of another contraceptive method. RESULTS: The lactational amenorrhoea method was 99% effective when used correctly (that is, during lactational amenorrhoea and full or nearly full breast feeding for up to six months). At 12 months the effectiveness during amenorrhoea dropped to 97%. CONCLUSIONS: The lactational amenorrhoea method provided as much protection from pregnancy as non-breast feeding women experience with non-medicated intrauterine devices and barrier methods. The contraceptive effect of lactation cannot be attributed to lactational or postpartum abstinence.

Effectiveness of the lactational amenorrhea method in Pakistan.

OBJECTIVE: To determine the efficacy of the lactational amenorrhea method of family planning (amenorrhea during full or nearly full breastfeeding for 6 months postpartum). DESIGN: Prospective noncomparative study. SETTING: Normal breastfeeding women in Karachi and Multan, Pakistan, most delivered at home by a midwife. PATIENTS: Three hundred ninety-nine newly delivered mothers who successfully had breastfed a previous child and chose the lactational amenorrhea method to prevent a subsequent pregnancy, 391 of whom were followed for a full year. INTERVENTIONS: Mothers were taught, before or shortly after delivery, to use the method and were interviewed in their homes each month by a Lady Health Visitor. MAIN OUTCOME MEASURE: Life-table pregnancy rates. Periods of postpartum or lactational abstinence were excluded in the calculation of the pregnancy rates. RESULTS: During full or nearly full breastfeeding, while the women were amenorrheic and not otherwise contracepting, the rate of pregnancy was 0.6%. The pregnancy rate during lactational amenorrhea alone was 1.1% at 1 year postpartum. CONCLUSION: The lactational amenorrhea method was found to be highly effective for 6 months. A high degree of contraceptive protection endures for a full year during lactational amenorrhea, but not after the return of menses during breastfeeding.

PIP: 399 mother-infant pairs were admitted into the study, 99 in the rural areas around Multan and 300 in Karachi. 378 remained in the follow-up for the full year. The mean age of the volunteers was 27.2. 25% were from the rural areas, and 37.6% were able to read and write. The women reported an average of 4.4 pregnancies and had 3.9 living children. Only 6% ever had used a family planning method in the past, and this included withdrawal as well as modern contraceptive methods. 26.4% of the women returned to menses during the first 6 months postpartum, and 40.7% of the infants were given regular supplements by this time. Considering both factors together, 47.9% of women were still protected by the lactational amenorrhea method (LAM) by the end of the 6th month postpartum. By the end of the 8th month, virtually all infants were receiving regular supplements, although only 7.4% had been weaned by the end of follow-up at 1 year postpartum. By the end of 12 months there were 29 pregnancies, including two miscarriages. Of the two pregnancies that occurred during amenorrhea, one occurred after 5 months postpartum (single LAM failure) and the other occurred at 9 months postpartum, 3.5 months after regular supplementation began. The single LAM failure, which occurred during the 6th postpartum month, resulted in a life-table pregnancy rate of 0.58% (95% confidence interval [CI], 0.00-1.58%). The rate of pregnancy during the first 6 months postpartum during breastfeeding in the absence of the use of another contraceptive constituted the failure rate of the LAM during correct plus incorrect use. During use of the LAM so defined, 0.96% were pregnant by the end of 5 months postpartum (95% CI, 0.00-2.15%) and 1.65% were pregnant by 6 months (95% CI, 0.12-3.18%). Two pregnancies occurred by the end of a year, for a 12-month life-table pregnancy rate of 1.12% (95% CI, 0.00-2.59%).

Progestin-only pill use and pill switching during breastfeeding.

The opinions of 20 international experts in reproductive endocrinology and family planning service delivery were solicited concerning contraceptive pill use during breastfeeding and, in particular, to determine whether the experts felt that breastfeeding women who use progestin-only pills (POPs) should be advised to switch to combined estrogen-progestin pills (COCs) during lactation. The experts agreed that POPs can be used safely and effectively throughout the period of lactation and there is no need to switch to another contraceptive method or another type of pill. If, however, a woman wishes to switch to COCs while she is still breastfeeding, it is acceptable for her to do so after six months postpartum.

Breastfeeding and the symptothermal method.

This prospective study was conducted among experienced users of periodic abstinence methods in Sydney, Montreal, and Birmingham (England) in order to describe the relationship between a laboratory measurement of ovulation and the natural symptoms of fertility during breastfeeding. Daily urinary estrogen and pregnanediol glucuronide assays were used to estimate the date of ovulation and to determine potentially fertile days. A standard set of Symptothermal Method (STM) rules was applied to daily STM records to assess the correspondence of the natural symptoms of fertility to the underlying hormonal profile. The STM symptoms and rules accurately identified 77-94 percent of the women's potentially fertile days, but abstinence was also recommended on about half of the days when the women were not fertile. An integrated set of common rules for STM use during breastfeeding is highly sensitive but not specific in its ability to screen for ovulation.

PIP: Periodic abstinence from sexual intercourse as a pregnancy prevention technique is sometimes the sole method used by women. The effectiveness of this technique is based on the woman's ability to fully understand her own menstrual cycle. Factors like breastfeeding and endocrine irregularities have been shown to interfere with a women's ability to determine periods of fertility. This article reports on a prospective study on the relationship between breastfeeding and hormonal levels, as a measurement of fertility, in women using periodic abstinence. The 73 women in this study were from England, Canada, and Australia. All women were breastfeeding. Daily symptothermal method (STM) records, which documented the cervical mucus conditions and basal body temperature, were kept. All women had experienced healthy pregnancies. Chi-square analysis and the analysis of variance (ANOVA) were the statistical methods employed. Significantly less abstinence is recommended by the STM rules during the anteovulation stage than during either of the later stages. Significantly less abstinence is also recommended during amenorrhea than after the first menstrual period. During the anteovulation stage, significantly fewer days were reported with fertile-type mucus than later stages. First ovulations were reported in 48 women (65%) during amenorrhea; of these, 25 (52%) were characterized as having adequate luteinization for conception. The STM method used in this study was considered to be sensitive but lacked specificity.