To elucidate the risk factors for anal cancer, we interviewed and obtained blood specimens from 148 persons with anal cancer and from 166 controls with colon cancer in whom these diseases were diagnosed during 1978-1985. We found that in men, a history of receptive anal intercourse (related to homosexual behavior) was strongly associated with the occurrence of anal cancer (relative risk, 33.1; 95 percent confidence interval, 4.0 to 272.1). Anal intercourse was only weakly associated with the risk of anal cancer in women (relative risk, 1.8; 95 percent confidence interval, 0.7 to 4.2). Among the subjects with squamous-cell anal cancer, 47.1 percent of homosexual men, 28.6 percent of heterosexual men, and 28.3 percent of women gave a history of genital warts, as compared with only 1 to 2 percent of controls and no patients with transitional-cell anal cancer. In patients without a history of warts, anal cancer was associated with a history of gonorrhea in heterosexual men (relative risk, 17.2; 95 percent confidence interval, 2.0 to 149.4) and with seropositivity for herpes simplex type 2 (relative risk, 4.1; 95 percent confidence interval, 1.9 to 8.8) and Chlamydia trachomatis (relative risk, 2.3; 95 percent confidence interval, 1.1 to 4.8) in women. Current cigarette smoking was a substantial risk factor in both women (relative risk, 7.7; 95 percent confidence interval, 3.5 to 17.2) and men (relative risk, 9.4; 95 percent confidence interval, 2.3 to 38.5). We conclude that homosexual behavior in men is a risk factor for anal cancer, and that squamous-cell anal cancer is also associated with a history of genital warts, an association suggesting that papillomavirus infection is a cause of anal cancer. Certain other genital infections and cigarette smoking are also associated with anal cancer.

All women attended prenatal care more frequently than the WHO's recommended 4 visits; however, early adolescents attended significantly less often than late adolescents or adult women. Further study of this inequality is warranted to adequately inform local health services.

Major risk factors for stillbirth include lack of skilled birth attendants, low socioeconomic status, poor nutrition, prior stillbirth, advanced maternal age, and the lack of prenatal care [1]. The World Health Organization has published a prenatal care model that includes 4 routine visits for women with no specific risk condition or risk factor, and additional visits for women with health problems or risk factors [2]. During these visits, risk factors should be ascertained (e.g., syphilis screening, measurement of blood pressure) and treatments administered (e.g., iron supplementation). In Peru, the Ministry of Health recommends a schedule of 6 routine prenatal care visits with a series of assessments or interventions to be performed at specific visits [3]. However, for various reasons, the availability, accessibility, and utilization of prenatal care services may be less than optimal. In order to best inform prenatal care services in the Amazon region of Peru, where poverty remains high, we sought to identify risk factors associated with stillbirth in women delivering at the Hospital Iquitos "César Garayar Garcia" in Iquitos, the capital city of Loreto.Data were obtained from a cohort study of birth outcomes, where a random sample of mother-baby medical records had been drawn from the hospital birth registry [4]. Demographic information, admission diagnosis, observations during delivery, and discharge diagnosis were abstracted. Gestational age was determined from date of last menstrual period (LMP). If this information was missing, the gestational age recorded at admission was used; women were excluded from the study if both LMP and gestational age were missing. We also excluded women whose pregnancy was shorter than 28 weeks and those with no information on prenatal care.Two separate analyses were carried out: (1) to examine the association between having completed the recommended number of prenatal care visits according to gestational age and the risk of stillbirth, using all neonates as the denominator; and (2) to examine the association between the number of visits completed and the risk of stillbirth, using those babies born between 36 and 40 weeks of gestation whose mothers should have had 5 prenatal care visits (according to the Ministry of Health's recommendation) as the denominator. Odds ratios and 95% confidence intervals were computed from logistic regression analysis. Factors showing an association with stillbirth in simple regressions at P b 0.10 were included in multiple regression analysis. Final models included variables that were statistically significant at P b 0.05. A parity variable was also included because of its confounding effect on the association between maternal age and the risk of stillbirth.The protocol was approved by the Research Ethics Committee of the Research Institute of the McGill University Health Centre and by the Comité de Bioética of the Hospital Iquitos.A total of 4220 mothers were included. Of these, 6% had had no prenatal care visit at all during their pregnancy. The p...

To compare low birth weight (LBW: <2,500 g) between infants born to adolescent and adult mothers in Iquitos, Peru. A random sample of 4,467 records of women who delivered at the Hospital Apoyo Iquitos between 2005 and 2007 was collected from hospital birth registries. Multivariate logistic and linear regression analyses were performed to compare LBW in newborns of adolescents (10-14, 15-19 years) and adults (≥20 years) and then for primiparous mothers with a normal gestational age, adjusting for newborn sex, antenatal care, and location of the mother's residence. A total of 4,384 mothers had had a singleton live birth and 1,501 were primiparous with a normal gestational age. Early and late adolescents had significantly greater odds of having a LBW infant than adults (OR = 2.28, 95%CI: 1.09, 4.78; OR = 1.67, 95%CI: 1.30, 2.14, respectively). For primiparous mothers with a normal gestational age, the same was true only for early adolescents (OR = 3.07, 95%CI: 1.09, 8.61). There were significant differences in mean birth weight between adults (3178.7 g) and both adolescent age groups overall (10-14 years: 2848.9 g; 15-19 years: 2998.3 g) and for primiparous mothers with a normal gestational age (10-14 years: 2900.8 g; 15-19 years: 3059.2 g; ≥20 years: 3151.8 g). Results suggest there is an important difference between adolescent and adult mothers in terms of newborn birth weight, especially among early adolescents. Future research on LBW and possibly other adverse birth outcomes should consider early adolescents as a separate sub-group of higher risk.