Placental characteristics and reduced risk of maternal breast cancer.

BACKGROUND: Women who have preeclampsia during pregnancy are at reduced risk of subsequent breast cancer. We examined whether other markers of reduced placental size or function, including increased blood pressure during pregnancy, predict a reduction in maternal breast cancer. METHODS: The Child Health and Development Studies is a 40-year follow-up of pregnant women enrolled in the Kaiser Permanente health plan between 1959 and 1967. We identified 3804 white women for whom data were available on placental examinations and other study variables. As of 1997, 146 women had developed invasive breast cancer. Proportional hazards models were used to estimate associations of breast cancer with markers of placental function. All statistical tests were two-sided. RESULTS: A blood pressure increase between the second and third trimesters exhibited a linear relationship with breast cancer rate, with the highest quartile showing a 51% reduction (95% confidence interval [CI] = 20% to 70%) that was not explained by preeclampsia. Smaller placental diameter was independently associated with a reduced breast cancer rate; the association increased with age at first pregnancy (P =.008). Maternal floor infarction of the placenta was associated with a 60% reduction in breast cancer rate (95% CI = 12% to 82%). In combination, placental risk factors were associated with a reduction in the breast cancer rate of as high as 94% (95% CI = 80% to 98%). CONCLUSIONS: Smaller placentas, maternal floor infarction of the placenta, and increasing blood pressure during pregnancy were associated with reduced maternal breast cancer. In the case of smaller placental diameter, the larger reduction observed with older age at first pregnancy suggests a process in which promotion of an existing lesion is blocked. Elucidating the mechanisms for these associations could provide clues to breast cancer prevention and treatment.

Prospective study of antibody to human papilloma virus type 16 and risk of cervical, endometrial, and ovarian cancers (United States).

OBJECTIVE: Human papilloma virus (HPV) is frequently detectable in cancers of the cervix, vagina, and vulva, but its role in endometrial and ovarian cancers is less certain. This analysis aimed to examine the association of presence of HPV type 16 (HPV-16) antibodies with subsequent risk of cervical, endometrial, and ovarian cancers. METHODS: In a prospective study enrolling over 15,000 pregnant women, pre-cancer sera from women who developed cervical (n = 83), endometrial (n = 34), and ovarian (n = 35) cancers were compared with sera from 172 control women frequency-matched by age group and race. RESULTS: HPV-16 seropositivity (OR = 2.0, 95% CI 1.0-3.4) was associated with cervical cancer, with the association more prominent for cancers occurring within 10 years of serum sampling (OR = 2.3, 95% CI 1.0-5.3) than cancers occurring later (OR = 1.6, 95% CI 0.75-3.6). Overall, the associations between HPV-16 seropositivity and endometrial (OR = 1.6, 95% CI 0.64-3.8) and ovarian cancers (OR = 1.1, 95% CI 0.43-2.8) were not significant, although the odds ratios for those cancers occurring within 20 years after serum sampling were similar to that for cervical cancer (OR = 2.2 for both). CONCLUSIONS: Our results confirm that HPV-16 infection precedes the development of cervical cancer. Predictability of HPV-16 seropositivity for risk of other female cancers warrants further investigation.

Levels of maternal serum alpha-fetoprotein (AFP) in pregnant women and subsequent breast cancer risk.

High maternal serum alpha-fetoprotein (AFP) levels during pregnancy may be instrumental in reducing the subsequent risk of breast cancer. This hypothesis was tested in a nested case-control study using stored frozen sera accrued between 1959 and 1966 by the University of California at Berkeley Child Health and Development Studies (CHDS) group from a cohort of pregnant women. Cases with histologically confirmed breast cancer were identified from California Cancer Registry files covering their date of enrollment in the CHDS until 1994. Controls were selected from the CHDS cohort by using randomized recruitment. Third-trimester maternal serum AFP levels were analyzed by using both a radioimmunoassay and an immunoenzymatic method. After controlling for multiple confounders in logistic regression models, the authors found an inverse association between high levels of maternal serum AFP (top quartile) during the index pregnancy and the risk of breast cancer. The protective effect of high levels of maternal serum AFP varied by age at first full-term pregnancy (age 20 years or less: odds ratio (OR) = 0.43, 95% confidence interval (CI) 0.28-0.65; age 21-23 years: OR = 0.62, 95% CI 0.41-0.92). After age 27 years, the estimated risk exceeded unity (OR = 1.67, 95% CI 1.14-2.45). These study findings suggest that some of the protection against breast cancer conferred by early first full-term pregnancy may result from high levels of maternal serum AFP. After age 27 years, a high maternal serum AFP level is not protective and may increase risk.

A medical record linkage analysis of abortion underreporting.

Inaccuracy in women's reports of their abortion histories affects many areas of interest to reproductive health professionals and researchers. The identification of characteristics that affect the accuracy of reporting is essential for the improvement of data collection methods. A comparison of the medical records of 104 American women aged 27-30 in 1990-1991 with their self-reported abortion histories revealed that 19% of these women failed to report one or more abortions. Results of logistic regression analysis indicate that nonwhite women were 3.3 times as likely as whites to underreport. With each additional year that had elapsed since the first recorded abortion, women became somewhat more likely to underreport (odds ratio of 1.3), while each additional year of a woman's education slightly decreased the likelihood of underreporting (odds ratio of 0.7).

PIP: Underreporting of abortion, prevalent both between and within populations, threatens to undermine the validity of research in this area. Estimates of abortion, contraceptive failure, miscarriage, and other reproductive history events that rely on self-reports are vulnerable to bias. This study sought to identify the characteristics associated with the likelihood of underreporting an abortion history. 651 respondents from the Child Health and Development Studies who were 27-30 years old in 1990-91 filled out self-administered reproductive health questionnaires; these results were then compared to the women's 1980-92 medical records. The final sample consisted of 104 women with a medical record of a total of 170 abortions. 90% of women who had at least one abortion in their medical record reported at least one abortion; only 56% reported all of their abortions within 1 year of the medical record date, however. Overall, 19% underreported their abortion history. Of these, half reported no abortions and half reported fewer abortions than were in the medical record. Another 46% reported the exact number of abortions, and 35% reported more abortions than were in the record. Non-White women were 3.3 times more likely than Whites to underreport abortion. For each year that elapsed since the procedure, the odds of underreporting increased by 26%. Finally, every additional year of schooling decreased the likelihood of underreporting abortion by 30%.

Childhood precursors of age at first intercourse for females.

Age at first intercourse for a sample of adult white women using variables measured during childhood is predicted. Childhood predictors were measured at birth, and ages 5 and 9-11, using existing public-use data on the women. Median age at first intercourse for the sample was 17.5 years. Early family predictors, early developmental characteristics, and temperamental characteristics during childhood together could predict about a fourth of the variance in age at first intercourse. The strongest predictors were motor skills and nightmares at age 5, church attendance with family at age 9, and domineering and mature personality at age 9.

The effect of forceps delivery on cognitive development.

OBJECTIVE: We evaluated the influence of forceps delivery on cognitive development of preschool children. STUDY DESIGN: A cohort of 3413 children who were born at the Kaiser Permanente Medical Center in Oakland, California, were selected at age 5 for intelligence quotient testing with the Peabody Picture Vocabulary Test and the Raven Coloured Progressive Matrices. Data were analyzed by means of the Student t test to compare mean intelligence quotient scores of intervention modes of delivery with spontaneous delivery. RESULTS: No significant difference in intelligence quotient was seen in 1192 children delivered by forceps (114 midforceps) compared with 1499 who were delivered spontaneously. CONCLUSION: The association of forceps delivery with adverse cognitive development cannot be supported.

Thyroid antibodies as a risk factor for Down syndrome and other trisomies.

To test whether the presence of thyroid antibodies in a parent is a risk factor for meiotic nondisjunction, we measured the levels of thyroid antibodies in serum samples drawn during early pregnancy from 101 gravidas who delivered a child with a trisomy, from 11 gravidas who had had a trisomic child in a previous pregnancy, and from 44 of their husbands. For each case mother, three controls were randomly selected from the same population and matched for age, race, sex of the child, and hospital of birth. Cases and controls came from two longitudinal populations, the Child Health and Development Studies (CHDS) and the national Collaborative Perinatal Project (CPP), together comprising more than 70,000 live births. All cases with both a definite diagnosis of trisomy-Down syndrome (DS) or other-and available serum were included. Overall, there was no association between the presence of thyroid antibodies in a mother and a trisomy in her offspring (odds ratio [OR] = .98, confidence interval [CI] = .54-1.85). The lack of association was seen in all three subgroups (DS only, other trisomies, and DS in a previous pregnancy), in all ethnic groups, and in the age groups of white mothers either less than 30 years of age (OR = .80, CI = .40-1.6) or greater than or equal to 30 years of age (OR = 1.26, CI = .82-1.9). In the CHDS population, case fathers, as compared with control fathers, did not have a higher prevalence of thyroid antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

The California Child Health and Development Studies of the School of Public Health, University of California at Berkeley.

The Child Health and Development Studies are prospective longitudinal studies on medical and social aspects of pregnancies and on the health and development of children. Data have been assembled on about 20,000 pregnancies occurring in one hospital between 1959 and 1967, and on follow-up of the children through adolescence. A currently ongoing project updates certain vital statistics of the entire study population. The data assembled in this longitudinal study supported a wide range of research projects, several of which proved to be important for the health of mothers and children. Notwithstanding, subsets of the assembled data, with potential value for public health, have not yet been explored. The data archive has been made accessible to the research community at large so that other significant research topics can be investigated. In the following article, brief descriptions are given of the history and design of the Child Health and Development Studies, of the contents of the data archive, and of the major areas of research that have been explored. Procedures to obtain access to the data and to the user's manual are explained, and a bibliography is included.

Adolescent smoking and early respiratory disease: a longitudinal study.

The data from a longitudinal study involving 1,445 white boys and girls from the San Francisco Bay area revealed a significant association between the adoption of cigarette smoking in adolescents with a history of either asthma or bronchitis in childhood and in early and middle teenage years. The association, present in both sexes, is stronger for bronchitis than for asthma, with the strength and direction of the association unaffected by such potentially confounding variables as parental smoking, socioeconomic status, psychosocial traits, etc. Age of onset of asthma (primarily in early childhood) preceded the commencement of smoking in 90% of subjects, indicating that cigarette smoking is not causally related to the development of childhood and adolescent asthma. With respect to bronchitis, however, as a result of the data on age of onset and the temporal relationship with the adoption of smoking, the possibility that cigarette smoking among adolescents may contribute to bronchitis cannot be dismissed.

Adolescents' preference of source to obtain contraceptive information.

PIP: The Adolescent Study, performed as part of the Child Health and Development Studies (CHDS), included an interview in which the adolescents were asked to respond to questions on social and family planning. The adolescents' responses to 1 particular question of this interview regarding the place or person to whom the adolescent would go for information on pregnancy prevention appears to be of particular pertinence in relation to the current issues regarding "Parental Notification Regulations." Recently, the federal government adopted the regulation that agencies receiving funds under Title 10 of the Public Health Service Act must notify a parent or guardian of an unemancipated minor (17 years of age or younger) within 10 days after a prescription contraceptive drug or device has been issued. The regulation has been opposed by major medical associations and has been challenged in court in a lawsuit brought by the Planned Parenthood Federation of America, Inc., resulting in a permanent injunction barring the government from enforcing or implementing the regulation. The government has appealed this decision. The main focus of the Adolescent Study was on blood pressure measurements of adolescents and their mothers. The study also included anthropometric and spirographic measurements, health interviews, and behavioral and attitudinal questionnaires of adolescents and their mothers. 31.4% of the 15 year old girls chose their mother as the person they would be most likely to go to for more information on pregnancy or pregnancy prevention. This proportion was 23.0% for 16 year old girls and 20.5% among the 17 year olds. The choice of father and mother was reduced from 5.6% for 15 year old girls to 1.8% for the 17 year olds. Father exclusively was never mentioned by the girls. For the boys, both parents were preferred by about 10% of the boys and father alone or mother alone, about equally by 7-8% of the boys. The single 1st choice most often mentioned was birth control clinics, increasing for girls from 20% at 15 years to 34% at 17 years. For boys, the percentage was more constant by age at about 26%. A doctor was mentioned as the primary source of information by about 10% of the aodlescent boys and girls. Besides these choices, either another relative or an adult friend or as a friend of the same age was mentioned by about 30% of the adolescents. The data suggest that even if family relationships are favorable, the majority of adolescents intend to seek advice on conception and contraception primarily outside the family.^ieng

Incidence of congenital anomalies among white and black live births with long-term follow-up.

The incidence of congenital anomalies at birth and accumulated to five years is presented for live-born children in a large prospective study. Congenital anomalies are not all diagnosable at birth; our data demonstrate that the incidence rate increases approximately three-and-one-halffold for Blacks and approximately fivefold for Whites between six days of age and five years of age. The incidence of congenital anomalies at birth was higher among Black children than White children, but there were no notable differences between the groups in incidence accumulated to age five years. At five years, the incidence rate of severe and moderate (but not trivial) congenital anomalies amounted to 15 per cent; for severe congenital anomalies, 4 per cent. Severe congenital anomalies diagnosed through age five years were observed to have a much higher incidence among children who weighted 2500 gm or less at birth than among those who were heavier.

The relationship between hormonal pregnancy tests and congenital anomalies: a prospective study.

In a prospective study of some 20,000 pregnancies in the Child Health and Development Studies in the San Francisco East Bay area, 226 gravidas were tested for pregnancy with estrogen/progestogen preparations. The two control groups were women who were tested for pregnancy by either a serum or urine test. There were no statistically differences (p greater than 0.05) in the rates of severe congenital anomalies between the hormone test group and the two control groups. The relative risks and the 95% confidence intervals were 1.01 (0.47-2.19) for the hormone/serum test comparison and 1.60 (0.60-4.18) for the hormone/urine test comparison.

PIP: Several retrospective and prospective studies have positively associated EPP (estrogen/progestogen preparations) with birth defects in the offsprings of exposed gravidas. Some 20,000 pregnancies of women in the Child Health and Development Studies (CHDS) in the San Francisco bay area between 1959 and 1966 were observed longitudinally. Congenital defects of children in the study (ascertained at birth and followed up in subsequent years) include structural aberrations and errors of metabolism. The CHDS study population includes 227 gravidas who were tested for pregnancy with EPP. 2 control groups consisted of those who were tested for pregnancy by either a serum or urine test. No statistically significant differences in the rates of severe congenital defects were observed between the hormonal test group and the 2 control groups (p 0.05). Relative risks and 95% confidence intervals were 1.01 (0.45-2.19) for the hormone/serum test comparison and 1.60 (0.60 to 4.18) for the hormone/urine test comparison. An insignificant increased risk for nonsevere genitourinary anomalies as observed in the male infants in the hormone group. Although this study did not confirm the hypothesized association between EPP and congenital anomalies in the CHDS population, the numbers in this series are not large enough to reject the hypothesis either. Further use of hormonal pregnancy tests appears unjustified in the light of the availability of non-risk pregnancy tests.

Comparisons of blood pressure measurements by auscultation and Physiometrics Infrasonde recording techniques.

The levels of blood pressures measured by a Physiometrics Infrasonde recorder (model SR-2) were compared with the levels simultaneously measured byt auscultation utilizing a standard mercury sphygmomanometer (Baumanometer). The measurements were made on 1530 adult women and their 1760 adolescent children 15-17 years old. Two sets of blood pressures were taken about 3 minutes apart, each with an occluding cuff connected to the Physiometrics recorder as well as to the mercury sphygmomanometer. The reproducibility of the Physiometrics method was similar to that of the auscultation method. The means of the systolic pressures measured by the Physiometrics method were virtually equal to those of the auscultation method for women and girls; for boys, the means of the former method surpassed those of the latter by about 3 mm. The mean diastolic pressures by the Physiometric method were very close to the Korotkoff sound 5 (K5) pressure by the auscultation method for all three groups. The correlation coefficients between both methods were 0.98 for the systolic and 0.93 for the diastolic pressure of the adult women, and 0.94 for the systolic pressure of the adolescents. The correlations between the two diastolic pressures of adolescents were much less (0.69). The Physiometrics measurements were consistent with the measurements by auscultation for systolic and diastolic pressures of women and systolic pressure of adolescents, but the consistency was low for diastolic pressure of adolescents. An effort has been made to relate differences between the two methods with other anthropometric variables, but the correlations with these variables were of low level.

The relationship of maternal attitude to pregnancy outcomes and obstetric complications. A cohort study of unwanted pregnancy.

The relationships of maternal attitude to pregnancy outcome and obstetric complications were investigated in a prospective study of a group of 8,000 gravidas, enrolled in the Child Health and Development Studies, who were members of the Kaiser Foundation Health Plan in the San Francisco East Bay Area. Interviews which were conducted early in pregnancy determined the mother's attitude through an open-ended question, "How do you feel about having a baby now?" The responses to this question were categorized as strongly favorable, ambivalent, or negative. Biomedical factors which were related to negative maternal attitude were perinatal death, congenital anomalies, and postpartum infection or hemorrhage. Other factors which were found to be related to maternal attitude toward pregnancy were clinic visits for psychosocial complaints related to anxiety states, and accidental injuries during pregnancy, as well as need for analgesics during labor. Birth weight of the infant, duration of gestation, length of labor, prenatal complications, and intrapartum obstetric complications were not related to maternal attitude. In order to control for the effect of confounding factors, these relationships were analyzed by using a multicontingency table approach and stratifying the data by parity, age of mother, and socioeconomic status.

Sudden infant death syndrome risk factors. Prospective data review.

Prospective data from a population of newborn infants were searched for risk factors for Sudden Infant Death Syndrome (SIDS). Maternal smoking, younger maternal age, short intervals between pregnancies, gestational age of less than 40 weeks, birth weight of less than 3000 g, lower socioeconomic status and male sex were factors found to be associated with SIDS. Race, blood type, maternal hemoglobin level, placental abnormality and newborn condition were not associated with SIDS in this population. Scoring systems to predict which infants will die of SIDS are not yet sensitive enough for clinical use.

Variations in utilization of health services by children.

In this longitudinal study in two prepaid group practices, many more children stayed at the same level of use of services over a six- to ten-year period than would be expected if use of services had distributed randomly. Overall, about 13% remained consistently in the highest third of the distribution of use, and another 13% remained consistently in the middle or lowest third. If use of services had distributed randomly, 4% and 7%, respectively, would have been in these groups. Conversely, many fewer children (25%) showed fluctuating patterns of use over time than would be expected by chance alone (37%). Although the reasons for this phenomenon are unknown (and may be multiple), the findings have implications both for clinical care and for development of policy regarding the organization and financing of health services for children.

The California Child Health and Development Studies: twenty years of research.

The Child Health and Development Studies are prospective longitudinal studies of pregnancy and delivery, and of health and development of the children from birth until adolescence. The studies are conducted on members of a prepaid medical insurance plan, and reside in the Oakland area of California, USA. The infants were born in one hospital, between 1659 and 1967. A variety of biomedical studies have been published; these have been summarized in separate sections representing the major research projects. Currently, an adolescent study is in progress in which the older children of the study cohort participate.