Prospective study of blood and tibia lead in women undergoing surgical menopause.

Despite the dramatic decline in environmental lead exposure in the United States during the past couple of decades, concern has been expressed regarding mobilization during menopause of existing lead stored in bone. To investigate whether bone lead concentrations decrease and blood lead levels increase, we conducted a prospective study of 91 women who were scheduled to undergo a bilateral oophorectomy for a benign condition at Mount Sinai Hospital in New York City during October 1994 through April 1999. We excluded women who were younger than 30 years of age or who were postmenopausal at the time of the surgery. We observed a small but significant increase in median blood lead levels between the baseline visit and the 6-month visit (0.4 microg/dL, p<0.0001), particularly for women who were not on estrogen replacement therapy (0.7 microg/dL, p=0.008). No significant change was observed in blood lead values between 6 and 18 months postsurgery, nor was there evidence of significant changes in tibia lead concentrations during the follow-up period. These findings do not point to substantial mobilization of lead from cortical bone during menopause.

In utero pesticide exposure, maternal paraoxonase activity, and head circumference.

Although the use of pesticides in inner-city homes of the United States is of considerable magnitude, little is known about the potentially adverse health effects of such exposure. Recent animal data suggest that exposure to pesticides during pregnancy and early life may impair growth and neurodevelopment in the offspring. To investigate the relationship among prenatal pesticide exposure, paraoxonase (PON1) polymorphisms and enzyme activity, and infant growth and neurodevelopment, we are conducting a prospective, multiethnic cohort study of mothers and infants delivered at Mount Sinai Hospital in New York City. In this report we evaluate the effects of pesticide exposure on birth weight, length, head circumference, and gestational age among 404 births between May 1998 and May 2002. Pesticide exposure was assessed by a prenatal questionnaire administered to the mothers during the early third trimester as well as by analysis of maternal urinary pentachlorophenol levels and maternal metabolites of chlorpyrifos and pyrethroids. Neither the questionnaire data nor the pesticide metabolite levels were associated with any of the fetal growth indices or gestational age. However, when the level of maternal PON1 activity was taken into account, maternal levels of chlorpyrifos above the limit of detection coupled with low maternal PON1 activity were associated with a significant but small reduction in head circumference. In addition, maternal PON1 levels alone, but not PON1 genetic polymorphisms, were associated with reduced head size. Because small head size has been found to be predictive of subsequent cognitive ability, these data suggest that chlorpyrifos may have a detrimental effect on fetal neurodevelopment among mothers who exhibit low PON1 activity.

Is discordant growth in twins an independent risk factor for adverse neonatal outcome?

OBJECTIVE: To estimate whether discordant growth is associated with adverse perinatal outcomes in twins after adjusting for growth restriction. METHODS: This was a retrospective, hospital-based cohort study of twin gestations with 2 live births delivered at 24 weeks or later from 1992 to 2001. Twin gestations were classified as small for gestational age (SGA) if one or both infants was less than the 10th percentile at birth by singleton Brenner norms and discordant if there was a 20% or more weight discordance. RESULTS: Of 1318 twin pairs, 856 were appropriate for gestational age (AGA) and concordant, 70 pairs were AGA and discordant, 254 pairs were SGA and concordant, and 138 pairs were SGA and discordant. The 4 groups had similar maternal demographics and medical comorbidity. When adjusting for chorionicity, antenatal steroid use, oligohydramnios, preeclampsia, and gestational age at delivery, discordant twins were more likely to have a cesarean delivery (odds ratio 1.87; 95% confidence interval 1.22, 2.87) and to be associated with some adverse neonatal outcomes (low and very low birthweight, neonatal intensive care unit admission, neonatal oxygen requirement and hyperbilirubinemia) independent of SGA status. A statistically nonsignificant trend (odds ratio 2.4; 95% confidence interval 0.99, 6.01) toward higher rates of intraventricular hemorrhage was noted in discordant twins, and no difference was seen for ventilator requirement, respiratory distress syndrome, or necrotizing enterocolitis. CONCLUSION: Discordance places twins at increased risk for some adverse perinatal outcomes, whether they are AGA or SGA. Discordance was not an independent risk factor for serious neonatal morbidity or mortality; however, this study was underpowered to detect those differences.

The descriptive epidemiology of second primary breast cancer.

BACKGROUND: It is well established that the incidence rates of first primary breast cancer have been increasing over time. In contrast, the incidence rates of second primary breast cancer are largely undocumented. This study describes the epidemiology of second primary breast cancer among a population-based cohort of 305,533 U.S. women diagnosed with breast cancer between 1973 and 1998. METHODS: We compared age-specific incidence rates for overall and second primary breast cancer according to year of diagnosis and demographic and tumor characteristics. RESULTS: Overall, age-specific rates of breast cancer increased with increasing age and year of diagnosis, whereas incidence of second primary breast cancer peaked among young women and declined after 1988. Consistent with what is known about genetic susceptibility to breast cancer, at every age the rate of second primaries was greater than the overall rate; among women age 20 to 29 years the rate of second primary was more than 100 times greater. Although overall age-specific rates of breast cancer for African-American women were lower than for whites, rates of second primaries were higher. Women with a first primary that was either lobular or medullary had a greater likelihood of developing a second primary, although, there were relatively few with these histologic types. CONCLUSIONS: The pattern of incidence rates for first and second primary breast cancer differ markedly over time and by age.

Clinical significance of subchorionic and retroplacental hematomas detected in the first trimester of pregnancy.

OBJECTIVE: To evaluate the long-term clinical significance of intrauterine hematomas detected in the first trimester of pregnancy in a general obstetric population. METHODS: A prospective study was designed to compare perinatal outcomes in 187 pregnant women with intrauterine hematomas and 6488 controls in whom hematomas were not detected at first-trimester ultrasonographic examination. RESULTS: The incidence of intrauterine hematoma in the first trimester in a general obstetric population was 3.1%. A retroplacental position of the hematoma was significantly correlated with an increased risk for adverse maternal and neonatal complications. The presence or absence of symptoms of threatened abortion did not affect these outcomes. The rates of operative vaginal delivery (relative risk [RR] 1.9; confidence interval [CI] 1.1, 3.2) and cesarean delivery (RR 1.4; CI 1.1, 1.8), as well as the rates of pregnancy-induced hypertension (RR 2.1; CI 1.5, 2.9) and preeclampsia (RR 4.0; CI 2.4, 6.7), were significantly greater in the hematoma group. Placental abruption (RR 5.6; CI 2.8, 11.1) and placental separation abnormalities (RR 3.2; CI 2.2, 4.7) were also significantly more frequent in the hematoma group. Perinatal complications, including the rate of preterm delivery (RR 2.3; CI 1.6, 3.2), fetal growth restriction (RR 2.4; CI 1.4, 4.1), fetal distress (RR 2.6; CI 1.9, 3.5), meconium-stained amniotic fluid (RR 2.2; CI 1.7, 2.9), and neonatal intensive care unit admission (RR 5.6; CI 4.1, 7.6), were also significantly increased in this group. Furthermore, the frequency of intrauterine demise and perinatal mortality was increased in the hematoma group, but this difference did not reach statistical significance (Ps =.6 and.2). CONCLUSION: Our study suggests that the presence of an intrauterine hematoma during the first trimester may identify a population of patients at increased risk for adverse pregnancy outcome.