Large bowel cancer in women in relation to reproductive and hormonal factors: a case-control study.

A community-based case-control study of the effect of reproductive factors on risk of large bowel cancer in Australia is described. The study involved 155 cases (99 colon cancer, 56 rectal cancer) and 311 controls who were interviewed with regard to pregnancies and their outcomes, lactation, menstrual history, and oral contraceptive (OC) use. Increasing parity was associated with a decreasing risk of colon cancer; para 0, relative risk (RR)=1; para 1-2, RR=0.9, 95% confidence interval (CI)=0.4-1.8; para greater than or equal to 3, RR=0.4, 95% CI=0.2-0.8; later age at first live birth (AFLB) was associated with increasing risk (AFLB less than or equal to 21 yr, RR=1; 22-25 yr, RR=2.3, 95% CI=1.0-5.5; greater than or equal to 26 yr, RR=2.7, 95% CI=1.2-6.2). These effects were independent of each other. Parity appeared to exert its predominant effect on risk of cancer of the right colon. OC use was more common among controls than cases (RR=0.5; 95% CI=0.3-1.2 for ever vs. never users) and showed a dose-response effect in multiple logistic analysis. The pattern of point-estimate RR for rectal cancer was largely congruent with those for colon cancer but was not significantly different from 1.0.

Breast cancer risk factors among screening program participants.

PIP: Data were obtained by mailed questionnaire from 405 breast cancer patients identified during the first 2 years of operation of the Breast Cancer detection Demonstration Project in the U.S. and from a sample of 1156 normal screenees (response rate = 88%) in an attempt to examine whetHer the usual risk indicators for breast cancer apply to individuals participating in screening programs. No substantial differences were found between the respondents and the nonrespondents for the variables on which information had been obtained at the time of the initial screening. Nearly all of t(e recognized risk factors were seen in this population. The relative risk (FF) of breast cancer was 3.9 among women whose mothers were also affected; this finding was statistically significant. Relative risk was increased for women reporting early menarche, late menopause, nulliparity, late age when 1st child was born, and excessive weight. The relative risk was not elevated in women with a prior breast biopsy but was excessive for those with more than 1 biopsy. No association with thyroid medications or menopausal hormones was found. Among women having undergone a natural menopause, a nonstatistically significant elevation in the relative risk was noted for long term oral contraceptive users; this excess relative risk was restricted to those using OCs in the presence of breast cancer risk indicators. The results indicate the need for further study of women with extended periods of OC use, particularly when accompanied by other known risk indicators.^ieng

Prospective study of oral contraceptive use and risk of breast cancer in women.

In 1976, 118,273 female nurses 30-55 years of age with no history of cancer completed a questionnaire regarding possible risk factors. By 1986, after 1,137,415 person-years of follow-up, we had documented 1,799 newly diagnosed cases of breast cancer. Compared with the risk of breast cancer for nonusers of oral contraceptives, the multivariate relative risks were 1.07 (95% confidence interval, 0.97-1.19) for all users, 1.06 (95% confidence interval, 0.96-1.18) for past users, and 1.53 (95% confidence interval, 1.06-2.19) for current users--women who used oral contraceptives up to 2 years before diagnosis of breast cancer. We conclude that overall past use of oral contraceptives is not associated with a substantial increase in the risk of breast cancer. Although we did not find women who used oral contraceptives before the first pregnancy to have an increased risk of breast cancer, the number of women who used oral contraceptives for a long duration in early reproductive life was too small to permit firm conclusions regarding the risk in this subgroup.

Parity and primary liver cancer among young women.

PIP: Researchers from the US National Cancer Institute compared data on 25-49 year old US women who died of primary liver cancer between 1985 and 1986 with data on age matched controls who died of causes other than liver conditions or oral contraceptive (OC) related conditions to determine the association between primary liver cancer and parity. Women who had experienced at least 1 live birth wear 1.9 times more likely to have died of primary liver cancer than were nulliparous women. The association was not significant (p=.22), however. The highest risks were among children with at least 6 children (odds ratio [OR]=2.9) and with 2 children (2.1). Further the risks were greater when the parents or spouse completed the questionnaire and the association almost reached significance (p=.07). This may have been due to parents and spouse providing more complete information than a friend or neighbor. The risks of developing primary liver cancer were higher among women who had never used OCs than they were among those who ever did. For example, the OR for never users past parity 2 was 3.6 compared with 1.3 for ever OC users. There was a higher risk associated with parity among long term OC users (=or 5 years) than with short-term OC users, however. The researchers concluded that since parity was positively associated with increased risk of primary liver cancer in the US (a low risk country), endogenous hormones may contribute to liver cancer development. The following facts add to this plausibility. Estrogen profiles of parous women are different from those of nulliparous women. Estrogen levels rise considerably during pregnancy. Estrogens alter liver metabolism. Pregnancy makes the body more defenseless against hepatitis and its sequelae. In low risk countries, the risk of primary liver cancer rises among women using exogenous hormones.^ieng

Reproductive factors and colorectal cancer risk among Chinese females.

We report results from a population-based case-control study of colorectal cancer among Chinese women in western North America (NA) and the People's Republic of China (China). A common protocol was used to assess reproductive characteristics and hormone use of 395 Chinese women (189 from NA and 206 from China) with cancer of the colon or rectum and of 1112 age-matched Chinese controls (494 from NA and 618 from China). In NA, risks for cancers of both the colon and rectum were lower among parous compared to nulliparous women (odds ratio for colorectal cancer, 0.6, P = 0.08), but the trend in risk was not smooth with increasing number of livebirths. This association with parity was absent for both cancer sites in China. There were no consistent patterns in the relationships between other reproductive factors (including age at menarche, age at first livebirth, menopausal status) and risk of colon and rectal cancer on either continent.

Uveal melanoma, hormonal and reproductive factors in women.

In a case-control study, we explored a potential association between uveal melanoma and reproductive factors in women. Responses from telephone interviews of 186 women diagnosed with uveal melanoma were compared with responses of 423 women without this disease. All women resided in 11 U.S. western states. We observed a decreased risk of uveal melanoma for women who had ever been pregnant [relative risk (RR) = 0.60, 95% confidence interval (CI) = 0.37 -0.95], with an increase in this protective effect with more live births after adjustment for age, menopausal status, eye color, and skin sensitivity to the sun (1-2 births, RR = 0.47,95% CI 0.29-0.78; 3-4 births, RR = 0.38, 95% CI = 0.22-0.64; 5 or more births, RR = 0.33, 95% CI = 0.15-0.71). The largest effect was observed between nulliparous and parous women. No other reproductive factors, including use of oral contraceptives or postmenopausal estrogens, were shown to be related to risk for uveal melanoma. We conclude that most reproductive factors in this population play little or no role in the etiology of uveal melanoma. The association with number of live births must be confirmed in other studies to assure that it is unrelated to confounding factors not measured in this study.

Population-based case-control study of ovarian cancer in Shanghai.

A case-control study of 229 ovarian cancer cases (including 172 epithelial tumors) and an equal number of population-based controls was conducted during 1984 to 1986 in Shanghai, China, a low-risk area for ovarian cancer. Similar to studies in high-risk areas, the risk of epithelial tumors was high for nulliparous women (odds ratio, 1.6; 95% confidence interval, 0.8 to 3.2) and decreased with increasing number of livebirths (P less than 0.01). Early menarche and late menopause were associated with increased risk, with the trend in risk for age at menarche being statistically significant. In contrast to other studies, oral contraceptive use was not associated with reduced risk, although there was some reduction in risk for those with a prior tubosterilization or intrauterine device use. Risk was also elevated among those reporting a prior ovarian cyst, medroxyprogesterone use, a first degree family history of cancer, and occupational exposure to paint. Risk factors for the nonepithelial tumors were similar to the other cancers, although the power to detect differences was limited.

Risk factors for breast cancer in Chinese women in Shanghai.

Five hundred thirty-four histologically confirmed incident cases of breast cancer in Chinese women of Shanghai and an equal number of age and sex-matched population controls were interviewed as part of an epidemiological study of breast cancer risk factors. Early age at menarche was positively associated with breast cancer risk whereas early age at first full term pregnancy, high parity, and long duration of nursing were each negatively associated. We found high average body weight to be a risk factor, especially among women over age 60. Use of oral contraceptives after age 45 also was a risk factor, but use in general was not. Personal history of benign breast disease and history of breast cancer in first degree female relatives both increased risk. Multivariate analysis showed that each of these risk (or protective) factors was independently related to breast cancer. In addition to confirming most of the breast cancer risk factors of Western populations in a low risk developing Asian country, this study demonstrates a clear beneficial effect on breast cancer risk of lactation in a population characterized by a long cumulative duration of nursing in the majority of women. Finally, this study supports several other recent reports of a residual and beneficial effect of parity on breast cancer risk after controlling for age at first full term pregnancy.

A case-control study of large bowel cancer and hormone exposure in women.

Several lines of evidence indicate a potential role for hormonal or reproductive factors in the subsequent development of large bowel cancer in women. To evaluate the relationship between hormone exposure and large bowel cancer a case-control study was carried out in 18 Illinois hospitals. Female cases, ages 45-74 (n = 90), and controls (n = 208) were identified from an ongoing large bowel cancer study. Data were obtained from medical records, personal interviews, and a subsequent mail survey with a questionnaire specific to hormone usage. Menopausal estrogen use was found to be protective with respect to the subsequent development of large bowel cancer with an odds ratio of 0.6 (95% CI, 0.33-0.99). This effect remained after controlling individually for age at diagnosis, ever pregnant (yes/no), parity, age at first birth, hysterectomy with documented oophorectomy, cholecystectomy, and appendectomy. Simultaneous adjustment, using logistic regression, for age at diagnosis, parity, hysterectomy, and cholecystectomy resulted in an adjusted odds ratio for menopausal estrogen use and large bowel cancer of 0.5 (95% CI, 0.27-0.90). Subsite analysis revealed the protective effect to be strongest for the rectal cancer cases. These data support the hypothesis that exogenous hormones may alter the risk of large bowel cancer in women.

Breast carcinoma etiological factors.

PIP: This review of breast carcinoma etiological factors considers the following: heritage; menses, marital state, and parity; breastfeeding; contraceptives; benign epithelial diseases of the breast; hormonal factors; cancer; iatrogenic factors; immunological factors; viral aspects of human breast cancer; dietary factors; and psychosomatic factors. Breast carcinoma is the most prevalent type of cancer in American women. 8% of American women can expect to be stricken with this disease. The rate in men is 1% that in women. The causes or reasons for a woman being afflicted with this disease remain equivocal. An abundance of evidence exists that the incidence of breast carcinoma varies greatly from 1 population to another throughout the world and that in most populations it is increasing. Due to earlier detection, improved medical care, and possible other factors, the death rate is not increasing as rapidly as the incidence rate. In general, the incidence is greatest in populations with the highest standards of living, such as those of Northwestern Europe and North America. Thus, a woman's heritage is usually a large factor in determining her low risk of developing mammary carcinoma. Heritage includes family, race, country of origin, religion, and any component of lifestyle that is firmly passed on from 1 generation to the next. These factors seem to have a great influence on the incidence of breast cancer, but there is little agreement on which components of heritage are most important and how they operate. Many publications report insignificant or no effect of menarchal age on breast cancer risk. Many reports mention breastfeeding along with other data in breast cancer etiological studies, but its influence on the disease seems to be insignificant. Possibly there is some synergistic influence, but available data is not strong enough to establish the direction. Many reports seem to suggest that oral contraceptives (OCs) increase risk in nulliparous women and may promote the growth of malignant neoplasia, but in parious women, if there is no incipient cancer present, OCs do not appear to increase risk and may even decrease risk. Benign epithelial lesions can be harbingers of breast carcinoma, but from the literature it is not easy to conclude the nature of the most risky lesions nor their relative risks. A familial or personal history of cancer in any location or tissue may increase the risk of breast cancer. Ionizing radiation, oophorectomy, hysterectomy, and hormone therapy are the principal iatrogenic factors that influence the incidence of breast cancer. Radiation is known to be a most powerful carcinogen and is probably responsible for more cancer than any other iatrogenic factor. None of the factors so far studied is of great importance singly, but in a situation where several act together, any one may appear to be significant.^ieng

Fertility and reproductive choice in women with HIV-1 infection.

OBJECTIVE: To measure fertility and birth rates and to describe the reproductive histories of women diagnosed with HIV-1 infection in Australia. METHODS: The medical records of 294 women with HIV-1 infection in four states of Australia were reviewed. Expected fertility and birth rates were calculated using national statistics. RESULTS: In the study population, 152 (52%) women had at least one pregnancy prior or subsequent to HIV-1 diagnosis. At maternal HIV-1 diagnosis, 71 (24%) women had a total of 106 children aged under 15 years. During the study period, 246 women were aged 15, 44 years and 58 (23%) of these became pregnant after HIV-1 diagnosis. Women whose exposure to HIV-1 was injecting drug use were twice as likely to become pregnant and more likely to have multiple pregnancies than women who did not report injecting drug use. The annual general fertility rate was 30 per 10,000 compared with 63 per 10,000 for the Australian female population aged 15-44 years, and the birth rate in women with HIV-1 infection was one-half that of the general female population. Of pregnancies confirmed after HIV-1 diagnosis, 47% were voluntarily terminated, a rate more than double that of the general population. All multiple terminations were among women whose exposure to HIV-1 was injecting drug use. CONCLUSIONS: Fertility and birth rates among women with HIV-1 infection are lower than the general population and the rate of termination higher. The results of this study provide a basis for the management of women with HIV-1 infection who are considering pregnancy.

PIP: Review of the medical records of 294 HIV-1-infected women in four states of Australia found the fertility and birth rates among those women to be lower and the rate of pregnancy termination higher than those of the general female Australian population. Expected fertility and birth rates were calculated using national statistics. 152 women had at least one pregnancy before or subsequent to HIV-1 diagnosis. At maternal HIV-1 diagnosis, 71 women had a total of 106 children under age 15 years. During the study period of 1987-92, 58 of the 246 women aged 15-44 years became pregnant after HIV-1 diagnosis. Women whose exposure to HIV-1 was IV drug use were twice as likely to become pregnant and more likely to have multiple pregnancies than women who did not report such drug use. The annual general fertility rate was 30/10,000 compared to 63/10,000 for the general Australian female population, while the birth rate among HIV-1-infected women was also half that of the general female population. Of pregnancies confirmed after HIV-1 diagnosis, 47% were voluntarily terminated, a rate more than double that of the general population. All multiple terminations were among women whose exposure to HIV-1 was through IV drug use.

Fertility rates in 238 HIV-1-seropositive women in Zaire followed for 3 years post-partum.

Birth-control use and fertility rates were prospectively determined in 238 HIV-1-seropositive and 315 HIV-1-seronegative women in Kinshasa, Zaire, during the 36-month period following the delivery of their last live-born child. No women delivered children during the first follow-up year. Birth-control utilization rates (percentage use during total observation time) and fertility rates (annual number of live births per 1000 women of child-bearing age) in the second year of follow-up were 19% (107.4 per 1000) for HIV-1-seropositive women and 16% (144.7 per 1000) for HIV-1-seronegative women. In the third year of follow-up these rates were 26 (271.0 per 1000) and 16% (38.6 per 1000) for HIV-1-seropositive and HIV-1-seronegative women, respectively (P less than 0.05 for the difference in birth-control utilization and fertility rates between seropositive and seronegative women in the third year of follow-up). Seven (2.9%) of the 238 HIV-1-seropositive women initially included in the study brought their sex partners in for HIV-1 testing; three (43%) of these men were found to be HIV-1-seropositive. New HIV-1 infection did not have a dramatic effect on the fertility of seropositive women. The nearly uniform unwillingness of HIV-1-seropositive women to inform husbands or sexual partners of their HIV-1 serostatus accounted in large part for the disappointingly high fertility rates in seropositive women who had been provided with a comprehensive program of HIV counseling and birth control. Counseling services for seropositive women of child-bearing age which do not also include these women's sexual partners are unlikely to have an important impact on their high fertility rates.

Perinatal transmission of HIV-1: lack of impact of maternal HIV infection on characteristics of livebirths and on neonatal mortality in Kigali, Rwanda.

We present the baseline results of a prospective cohort study on the perinatal transmission of HIV-1 in Kigali, Rwanda. HIV-1-antibody testing was offered to all women of urban origin delivering a live newborn at the maternity ward of the Centre Hospitalier de Kigali from November 1988 to June 1989; 218 newborns of 215 HIV-positive mothers were matched to 218 newborns of 216 HIV-negative mothers. The matching criteria were maternal age and parity. No differences in socioeconomic characteristics were observed between HIV-positive and HIV-negative women. HIV-positive mothers more frequently reported a history of at least one death of a previously born child (P less than 0.01) and a history of abortion (P less than 0.001). Most of the HIV-positive women were asymptomatic, but 72.4% of them had a CD4; CD8 ratio less than 1 versus 10.1% in the HIV-negative group (P less than 0.001). The frequency of signs and symptoms was not statistically different in the two groups, except for a history of herpes zoster or chronic cough, which was more frequent among HIV-positive women. The rates of prematurity, low birth weight, congenital malformations and neonatal mortality were comparable in the two groups. However, infants of HIV-positive mothers had a mean birth weight 130 g lower than the infants of HIV-negative mothers (P less than 0.01). The impact of maternal HIV-1 infection on the infant seems limited during the neonatal period.

Infection with HIV as a risk factor for adverse obstetrical outcome.

We carried out a case-control study to investigate the role of sexually transmitted diseases (STDs), including infection with HIV, as risk factors for adverse outcome of pregnancy. Overall, 1507 women were enrolled within 24 h of delivery. Cases (n = 796) were mothers of low-birthweight infants (less than 2500 g) or of stillborns. Low-birthweight infants were divided into preterms (n = 373) and neonates small for gestational age (n = 234). Stillborns were separated into intrauterine fetal deaths (n = 120), and intrapartum fetal deaths (n = 69). Controls were selected from mothers delivering a live baby of greater than or equal to 2500 g (n = 711). The maternal HIV seroprevalence in the control group was 3.1%. Prematurity was associated with maternal HIV antibody [8.6% seropositive; adjusted odds ratio (OR) 2.1; 95% confidence interval (CI) 1.1-4.0], as was being born small for gestational age (7.7% seropositive; adjusted OR 2.3; 95% CI 1.2-4.2). In mothers who delivered a stillborn baby, both intrauterine fetal death (11.7% seropositive; adjusted OR 2.7; 95% CI 1.3-5.5) and intrapartum fetal death (11.6% seropositive; adjusted OR 2.9; 95% CI 1.3-6.5) were independently associated with HIV seropositivity in the mother. Maternal syphilis was confirmed as an important risk factor for intrauterine fetal death (14.3% positive; adjusted OR 4.8; 95% CI 2.4-9.5). No significant association was found between other STDs, including gonococcal and chlamydial infection, and adverse obstetrical outcome. These results suggest an association between maternal HIV infection and adverse obstetrical outcome, defined as low birthweight and stillbirth.

Teenage pregnancy and fertility trends--United States, 1974, 1980.

PIP: This article presents data on teenage pregnancy and fertility in the US in 1974 and 1980. In 1974-80, the pregnancy rate for females aged 15-19 years increased by 8.2%, from 81.8/1000 to 88.5/1000. However, the rate for sexually active females in this age group decreased by 5.7%, from 204.5/1000 to 192.8/1000. In this period, the fertility rate of 15-19-year old females decreased by 9.2% overall and by 20.9% among the sexually active. The 921,696 pregnancies among 15-19-year olds in 1980 represented a 10.5% increase compared to 1974; however, the percentage of all births occurring to these females fell from 18.8% to 15.3% between 1974-80. In terms of females under 15 years of age, the number of pregnancies decreased from 24,128 in 1974 to 23,010 in 1980. On the other hand, the pregnancy rate for 12-14-year olds increased 10.3%, from 3.9/1000 in 1974 to 4.3/1000 in 1980. The fertility rate for younger teenagers decreased by 5% in this period, from 2 births/1000 to 1.9/1000. In 1980, there were 10,169 births to females under 15 years of age, representing an 18.8% decline from 1974. The percentage of all births to females in this age group fell from 0.4% to 0.3%. It is noted, editorially, that analyses of pregnancy and fertility trends must take into account the extent of sexual experience of adolescent females. Between 1971-82, the estimated percentage of never-married 15-19-year olds with premarital sexual experience increased from 26.8% to 42.8%. The absolute number of females aged 12-14 years is expected to decline 11.1% in 1980-90, from 5.4 million to 4.8 million, whereas the number of those 15-19 years should drop by 20.2% in this period, from 10.4 million to 8.3 million. US family planning objectives include no unintended births to females under 15 years of age and fertility rates of 10, 25, and 45 births/1000 females for those ages 15, 16, and 17 years, respectively.^ieng

Social consequences of psychiatric disorders, II: Teenage parenthood.

OBJECTIVE: The subject of this study was the relation between retrospectively reported early-onset psychiatric disorders and subsequent teenage parenthood in the general population. METHOD: The data were from 5,877 respondents aged 15-54 years in the National Comorbidity Survey, a nationally representative household survey. Information on respondents' DSM-III-R anxiety disorders, mood disorders, substance abuse disorders, and conduct disorder, age at the birth of the first child, and teenage sexual activity was collected in face-to-face interviews. RESULTS: Early-onset psychiatric disorders were associated with subsequent teenage parenthood among both females and males, with significant odds ratios of 2.0-12.0 and population attributable risk proportions of 6.2%-33.7%. Disaggregation analyses showed that disorders were associated with increased probability of sexual activity but not with decreased probability of using contraception. CONCLUSIONS: These results add to a growing body of evidence that psychiatric disorders are associated with a variety of adverse life consequences. The current policy debate concerning universal insurance coverage needs to take this into consideration. Planners of interventions aimed at preventing teenage pregnancy should consider including a mental health treatment component in their intervention packages. Mental health professionals treating adolescents need to be sensitized to their higher risk of pregnancy, while family doctors and specialists treating teenage mothers or their children need to be sensitized to the mothers' higher risk of psychiatric disorder.

PIP: Data from the US National Comorbidity Survey on 5877 respondents 15-54 years of age were used to assess the relationship between retrospectively identified early-onset psychiatric disorders and subsequent adolescent parenthood. Between 21-24% of the sample's male and female age cohorts reported having their first child at ages 15-19 years. The cumulative and conditional probability curves for adolescent parenthood were consistently higher among men and women with prior psychiatric diagnoses of anxiety, affective, addictive, and conduct disorders than among those without psychiatric diagnoses. The diagnosis most predictive of adolescent parenthood was addictive disorders. The population attributable risk proportions of births of first children to teenagers associated with the psychiatric disorders were 11.1% in the teenage female subsample with premarital childbearing, 6.2% in the teenage female subsample with marital childbearing, and 33.7% in the teenage male subsample with premarital parenthood. Physicians and mental health professionals who work with adolescents with psychiatric conditions should be aware of the increased risk of adolescent pregnancy and a mental health component should be added to adolescent pregnancy prevention programs.

Reproductive histories of low weight girls and women.

As shown in 79,000 girls and women participating in four different surveys, low body weight (less than or equal to 47.2 kg) does not prevent the attainment of menarche, conception, or even repeated conceptions. Indeed, low body weight is especially common in early maturing girls and in Puerto Ricans and Mexican-Americans. From these data, the concept of a "critical weight" for menarche is difficult to substantiate, although low body weight does have nutritional implications and is the second most important factor in regulating fetal growth.

PIP: As shown in 79,000 girls and women participating in 4 different surveys, low body weight less than or equal to (47.2 kg) is without influence in preventing the attainment of menarche, conception, or even repeated conceptions. Indeed, low body weight is especially common in early maturing girls and in Puerto Ricans and Mexican Americans. From these data, the concept of a "critical weight" for menarche is difficult to substantiate, although low body weight does have nutritional implications and is the 2nd most important factor in regulating fetal growth.

Biological determinants of pregnancy weight gain in a Filipino population.

Patterns of pregnancy weight gain and predictors of first trimester and total weight gain were investigated in a sample of 1367 women from Cebu, Philippines, with pregnancy intervals of < 2 y. The mean total weight gain based on actual measurements of prepregnant weight was 8.4 kg. Controlling for gestational week when weight was measured, multivariate-regression models predicted higher first trimester weight gain with higher parity, lower prepregnant body mass index (BMI), and longer nonpregnant intervals. Higher total weight gain was associated with longer nonpregnant intervals, lower prepregnant BMI, taller maternal stature, and relatively high dietary energy intakes. Lactation into the third trimester of pregnancy and maternal age over 35 y had significant negative effects on total weight gain. Given the importance of maternal weight gain in predicting birth outcome, this study provides information on modifiable risk factors that should be considered when developing maternal-infant health policy and programs.

PIP: A study of 1983-87 longitudinal data examined patterns of pregnancy weight gain and predictors of pregnancy weight gain among 1367 pregnant women from Cebu, the Philippines. Mean total weight gain was 8.4 kg. The women began gaining weight more slowly than did women in developed countries then caught up until 22-24 weeks gestation at which time their weight gain rate was considerably lower. Underweight women always gained more weight than normal and overweight women (e.g., during the 1st trimester, .07 kg/week vs. -.8 kg/week; p .05). During the 3rd trimester, women with an overlap of pregnancy and lactation gained much more weight than women with no overlap (.31 kg/week vs. .22 kg/week; p .05). The multivariate regression confirmed that women with a low prepregnant body mass index (BMI) gained more weight than did women with a normal or high BMI (p .01). Higher total weight gain during the 1st trimester was also linked to longer nonpregnant intervals (p .01). This was also true for total weight gain (p .01). A woman with a 6-month pregnancy interval gained 1.27 kg less during the entire pregnancy than a women with an 18-month pregnancy interval. Taller women gained more weight than did shorter women (p .01). Women who had high caloric intake gained more weight than did women who had low caloric intake (p .05). Women older than 35 gained less weight than younger women (p .01). Women who breast fed into the 3rd trimester of pregnancy gained 1.84 kg less than a woman who breast fed only into the 1st trimester (p .01). Women with any overlap of pregnancy and lactation gained more weight during the 3rd trimester than did women with no overlap, suggesting a rebound effect. Thus, public health programs should promote birth spacing and sound nutritional status and encourage breast-feeding pregnant mothers to consume more energy and nutrients to meet the demands of pregnancy and breast feeding.

Breast-feeding and family planning: a review of the relationships between breast-feeding and family planning.

A number of interrelated factors must be considered when breast-feeding is introduced as a concern for family planning programs: the number of pregnancies and births experienced, age at each pregnancy and birth, duration of the intervals between conceptions, lactation including duration and type, health and nutritional services available to meet the demands of pregnancy, delivery, and postpartum care. The dietary intake of the mother and her health and disease status have an effect on the duration of breast-feeding, and lactation has an effect on her ovulation and birth spacing. Those at particularly high risk include adolescent girls, older grand-multipara women, and families living in poverty. An historical relationship between the reduction in infant and childhood mortality and the falling off of births can be documented. The straightforward benefits on nutritional status of breast-fed infants, the conjunction with the antibody protection afforded by breast milk, served to reduce infant mortality and indirectly served to reduce birth rates. In addition, the prolongation of postpartum anovulatory cycles in breast-feeding women, coupled with sexual mores that postpone sexual relations while a women is breast-feeding in certain groups, will serve to prolong the interbirth intervals. Populations where breast-feeding is customary have been shown to have fewer births than populations where the women do not breast-fed and where infants are artificially fed.

PIP: Public health workers and social scientists favor breastfeeding because of the relationship between breastfeeding, infant survival, and family planning. Family planning in developing countries is a major concern among health professionals particularly because of the annual population growth rate of nearly 3% in these countries. Breastfeeding studies in West African villages, rural Philippines, Europe, India, and Taiwan show that breastfeeding prolongs interbirth intervals up to 35 months. It is calculated that breastfeeding in urban areas of developing countries would annually provide 3.4 million couple-years of protection against fertility, while for rural areas, the estimate is 34.7 million couple-years. Authors generally agree that lactation is usually associated with prolongation of postpartum amenorrhea. Because a lengthy period of lactation delays ovulation, this period of ovarian inactivity has been described as physiological castration. Postpartum amenorrhea may be influenced by seasonal patterns, as well as malnutrition of the mother. Other lactation factors which affect amenorrhea and prolongation of interbirth intervals are: 1) undernutrition of the breastfeeding woman, 2) taking of birth control pills, 3) cultural factors that include abstinence from sexual intercourse until weaning, 4) maternal age, and 5) education. Birth intervals are also affected by infant survival. The death of a child shortens the birth interval partly because of the absence of postpartum amenorrhea with lactation. In addition, parents tend to replace children who have died. This information could provide the basis for program development which would enhance the conscious awareness of better child survival through the combination of child care and family planning. The woman's age and temporary separations between spouses also affect pregnancy interval, as do the mother's health and nutritional status. Adolescents and older women are at high risk for problems during both pregnancy and lactation. Family planning programs should aim at improving adolescent nutrition, delaying 1st pregnancy, widening birth intervals, lowering parity, and encouraging both lactation and family planning.

Benefits associated with WIC supplemental feeding during the interpregnancy interval.

Interpregnancy WIC supplementation was evaluated by comparing maternal nutritional status indicators and subsequent birth outcomes of 703 WIC participants divided into two groups. Study group women received postpartum benefits for 5-7 mo while control group women received postpartum benefits for only 0-2 mo. Both groups received prenatal benefits during each of two study pregnancies. Infants born to study group women had a higher mean birthweight (131 g) and birthlength (0.3 cm) and a lower risk of being less than or equal to 2500 g. Additionally, at the onset of the second pregnancy study group women had higher mean hemoglobin levels and lower risk of maternal obesity. These results suggest that postpartum WIC supplementation has positive benefits for both the mother and her subsequent infants.

PIP: Nutritional depletion is often found in women of high parity and short intervals between births. Food supplementation for the postpartum woman may be a desirable intervention. Interpregnancy WIC (special supplemental food program for women, infants and children) supplementation was evaluated by comparing maternal nutritional status indicators and subsequent birth outcomes of 703 California WIC participants divided into 2 groups. Study group women received postpartum benefits for 5-7 months white control group women received postpartum benefits for only 0-2 months. Both groups received prenatal benefits during each of 2 study pregnancies. Infants born to study group women had a higher mean birthweight and birthlength and a lower risk of being less than 2500 grams. Additionally, at the onset of the 2nd pregnancy study group women had higher mean hemoglobin levels and lower risk of maternal obesity. Since many women do not enter the WIC program until 3 ro 4 months following conception, they miss the opportunity to receive supplemental nutrients when the need is most critical. From the observations in this study, increases in birthweight are not operating through increased gestation. For underweight women these results are compatible with the belief of most nutritionists that supplementation will increase energy reserves which are beneficial for normal fetal growth. Extended feeding during the interpregnancy interval improves both infant and maternal nutritional status by enhancing birthweight and birthlength and altering the prepregnancy weight of women to a more optimal level. Women receiving extended postpartum benefits compared to those receiving limited benefits had a lowered risk o fdelivering infants of low birthweight and 1/2 the odds of maternal obesity at the onset of their subsequent pregnancy. The magnitude of birthweight effects demonstrated in this study emphasize the potentially important role of interpregnancy nutrition in human reproduction.