Kenneth J Rothman

Massachusetts Department of Public Health, Boston, Massachusetts, United States

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Publications (285)2263.57 Total impact

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    ABSTRACT: We launched the Boston University Pregnancy Study Online (PRESTO) to assess the feasibility of carrying out an Internet-based preconception cohort study in the US and Canada. We recruited female participants age 21-45 and their male partners through Internet advertisements, word of mouth, and flyers. Female participants were randomised with 50% probability to receive a subscription to FertilityFriend.com (FF), a web-based programme that collects real-time data on menstrual characteristics. We compared recruitment methods within PRESTO, assessed the cost-efficiency of PRESTO relative to its Danish counterpart (Snart-Gravid), and validated retrospectively reported date of last menstrual period (LMP) against the FF data. After 99 weeks of recruitment (2013-15), 2421 women enrolled; 1384 (57%) invited their male partners to participate, of whom 693 (50%) enrolled. Baseline characteristics were balanced across randomisation groups. Cohort retention was similar among those randomised vs. not randomised to FF (84% vs. 81%). At study enrolment, 56%, 22%, and 22% couples had been trying to conceive for <3, 3-5, and ≥6 months, respectively. The cost per subject enrolled was $146 (2013 US$), which was similar to our companion Danish study and half that of a traditional cohort study. Among FF users who conceived, >97% reported their LMP on the PRESTO questionnaire within 1 day of the LMP recorded via FF. Use of the Internet as a method of recruitment and follow-up in a North American preconception cohort study was feasible and cost-effective. © 2015 John Wiley & Sons Ltd.
    Paediatric and Perinatal Epidemiology 07/2015; 29(4):360-71. DOI:10.1111/ppe.12201 · 2.81 Impact Factor
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    ABSTRACT: Periconceptional folic acid (FA) supplementation reduces the risk of neural tube defects and has been associated with ovulatory function. However, only two studies have associated supplementation with multivitamins (MVs) that contained FA with increased pregnancy rates. We aimed to examine the association between FA supplementation (obtained either through single FA tablets or through MVs) and fecundability. A prospective cohort study of 3895 Danish women who were planning a pregnancy between 2007 and 2011. We estimated fecundability ratios (FRs) and 95% confidence intervals (CIs) in relation to FA supplementation (either through single FA tablets or MV) using a proportional probabilities regression model, with adjustment for potential socio-demographic, reproductive and lifestyle confounders. In stratified analyses, we also estimated FR with 95% CI in relation to FA supplementation for women with regular and irregular cycles, respectively, and for women with short (<27 days), medium (27-29 days) and long cycles (⩾30 days), respectively. FA supplementation was associated with increased fecundability (FR=1.15, 95% CI=1.06-1.25), compared with non-use. The adjusted FRs for FA supplement use relative to non-use were 1.35 (95% CI=1.12-1.65) and 1.11 (95% CI=1.01-1.22) for women with irregular and regular cycles, respectively, and 1.36 (95% CI=0.95-1.95), 1.10 (95% CI=0.98-1.22) and 1.24 (95% CI=1.10-1.41) for women with short (<27 days), medium (27-29 days) and long cycles (⩾30 days), respectively. FA supplementation was associated with increased fecundability, and this association appeared to be stronger among women with irregular cycles and among women with either short or long cycle length.European Journal of Clinical Nutrition advance online publication, 17 June 2015; doi:10.1038/ejcn.2015.94.
    European journal of clinical nutrition 06/2015; DOI:10.1038/ejcn.2015.94 · 2.95 Impact Factor
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    ABSTRACT: Few studies have evaluated the association between pregravid oral contraceptive (OC) use and birth weight, and findings have been conflicting. We conducted a prospective cohort study of 5921 pregnancy planners in Denmark to evaluate recency, duration, and type of OC used before conception in relation to infant birth weight. Participants completed online questionnaires and reported detailed information on contraceptive history and covariates at baseline. Participants completed bimonthly follow-up questionnaires to update their pregnancy status for up to 12 months or until conception occurred. Birth weight data were ascertained from the Danish Medical Birth Registry for 4046 live births delivered by study participants between 2008 and 2010. We used multivariable linear and log-binomial regression analyses to control for confounding. Mean birth weight was higher among women who had used OCs within 0-1 months (mean difference = 97 g, CI 26, 168) or 2-6 months (mean difference = 40 g, CI -5, 85) before conception, compared with more than 12 months before conception. Mean birth weight was lower among women who had used OCs for long durations (mean difference comparing ≥12 with <4 years of OC use = -85 g, CI -158, -11). Our findings indicate that pregravid OC use within 6 months of conception may be associated with a small increase in birth weight, but that long duration of use may have the opposite effect. Results were stronger among male infants, among 2nd and 4th generation OC users, and among users of OCs with a higher estrogen dose.
    European Journal of Epidemiology 06/2015; DOI:10.1007/s10654-015-0053-2 · 5.15 Impact Factor
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    ABSTRACT: To examine the association between folic acid (FA) supplementation obtained through either single FA tablets or multivitamins (MVs) and menstrual cycle characteristics among 5386 women aged 18-40 years, enrolled in an Internet-based study of Danish women attempting pregnancy during 2007-2011. In a cross-sectional study, we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of FA supplementation with menstrual cycle regularity; short (<27 days), long (30-33 days), and very long (≥34 days) cycle lengths; and duration and intensity of menstrual bleeding. Compared with nonuse, FA supplementation was associated with reduced odds of short cycle length (OR = 0.80, 95% CI: 0.68-0.94) and a trend toward increased odds of very long cycle length (OR = 1.21, 95% CI: 0.87-1.68) compared with cycle length of 27-29 days. The inverse association with short cycle length was stronger among 18- to 30-year-old women (OR = 0.68, 95% CI: 0.53-0.87), nulliparous women (OR = 0.66, 95% CI: 0.52-0.84), and women who used both FA and MVs (OR = 0.75, 95% CI: 0.60-0.95). We found no clear association between FA supplementation and cycle regularity and duration and intensity of menstrual bleeding. FA supplementation was inversely associated with short menstrual cycle length. This association was strongest among women aged 18-30 years, nulliparous women, and women who used both FA and MVs. Copyright © 2015 Elsevier Inc. All rights reserved.
    Annals of Epidemiology 06/2015; DOI:10.1016/j.annepidem.2015.05.008 · 2.15 Impact Factor
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    ABSTRACT: In this nationwide population-based cohort study using national Danish registries, in the period 1980-2008, our aim was to study employment and receipt of disability pension after central nervous system infections. All patients diagnosed between 20 and 55 years of age with meningococcal (n = 451), pneumococcal (n = 553), or viral (n = 1,433) meningitis or with herpes simplex encephalitis (n = 115), who were alive 1 year after diagnosis, were identified. Comparison cohorts were drawn from the general population, and their members were individually matched on age and sex to patients. Five years after diagnosis, the differences in probability of being employed as a former patient with pneumococcal meningitis or herpes simplex encephalitis versus being a member of the comparison cohorts were -19.9% (95% confidence interval (CI): -24.7, -15.1) and -21.1% (95% CI: -33.0, -9.3), respectively, and the corresponding differences in probability of receiving disability pension were 20.2% (95% CI: 13.7, 26.7) and 16.2% (95% CI: 6.2, 26.3). The differences in probability of being employed or receiving disability pension in former meningococcal or viral meningitis patients versus members of the comparison cohorts were small. In conclusion, pneumococcal meningitis and herpes simplex encephalitis were associated with substantially decreased employment and increased need for disability pension. These associations did not seem to apply to meningococcal meningitis or viral meningitis. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
    American journal of epidemiology 04/2015; 181(10). DOI:10.1093/aje/kwu359 · 4.98 Impact Factor
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    ABSTRACT: Is caffeine and caffeinated beverage consumption associated with the risk of spontaneous abortion (SAB)? While preconceptional caffeine consumption was not materially associated with an increased risk of SAB, consumption during early pregnancy was associated with a small increased risk of SAB, although the relation was not linear. Caffeine has been hypothesized as a risk factor for SAB since the 1980s; however, results from previous studies have been conflicting. This prospective cohort study included 5132 Danish women planning pregnancy and enrolled from 2007 to 2010. Participants were women who conceived after entry into the Snart-Gravid cohort and who were aged 18-40, in a stable relationship with a male partner, and did not use fertility treatments to conceive. Women reported their daily caffeine and caffeinated beverage consumption on questionnaires before conception and during early pregnancy. All exposure measurements were prospective with respect to outcome ascertainment. We estimated hazard ratios (HRs) of SAB for categories of caffeine consumption in milligrams (mg) per day and the corresponding 95% confidence intervals (CIs) using Cox proportional hazards regression models with gestational weeks as the time scale. There were 732 women (14.3%) who were identified as having a SAB. In the preconceptional period, caffeine consumption was not materially associated with SAB risk (HR comparing ≥300 with <100 mg/day: 1.09; 95% CI: 0.89, 1.33). In early pregnancy, the HRs for 100-199, 200-299 and ≥300 mg/day of caffeine consumption were 1.62 (95% CI: 1.19, 2.22), 1.48 (95% CI: 1.03, 2.13) and 1.23 (95% CI: 0.61, 2.46), respectively, compared with that for <100 mg/day. The observed results may be affected by non-differential exposure misclassification, reverse causation and residual confounding. This is the largest study to date of prospectively measured, preconception caffeine consumption and risk of SAB. We were able to reduce the likelihood of differential left truncation bias and recall bias present in other analyses. Snart-Gravid was funded by the NICHD (R21-050264). Dr. Hahn's work was funded in part by the BU Reproductive, Perinatal, and Pediatric Epidemiology Training Grant NIH #T32HD052458. There are no competing interests. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
    Human Reproduction 03/2015; 30(5). DOI:10.1093/humrep/dev063 · 4.59 Impact Factor
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    ABSTRACT: We measured birth prevalence of major congenital malformations (MCMs) after topiramate use during pregnancy to screen for a possible signal of increased risk. Using four healthcare databases, we identified three cohorts of pregnant women: cohort 1, used topiramate during the first trimester; cohort 2, used topiramate or another antiepileptic drug previously but not during pregnancy; and cohort 3, were pregnant and did not use topiramate but had indications for use individually matched to those of users. Cohort 1 was compared with cohorts 2 and 3. MCMs were a code for any major congenital malformation dated within 30 days of the delivery date on the mother's claims or within 365 days after infant birth date, excluding a genetic or syndromic basis, and with procedure or healthcare usage consistent with the MCM diagnosis code in the 365 days after infant birth. Of the 10 specific common MCMs evaluated, 1 (conotruncal heart defects) had a prevalence ratio greater than 1.5 for both primary comparisons, and 4 (ventricular septal defect, atrial septal defect, hypospadias, coarctation of the aorta) had a prevalence ratio greater than 1.5 for one of the two comparisons. Following screening of organ systems with elevated MCMs, the prevalence ratio was greater than 1.5 for patent ductus arteriosus in both comparisons and for obstructive genitourinary defects in one comparison. To evaluate a large number of MCMs across many pregnancies, we used crude methods for detecting potential signals. Therefore, these results should be seen as potential signals, not causal. Birth Defects Research (Part A), 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    Birth Defects Research Part A Clinical and Molecular Teratology 03/2015; 103(4). DOI:10.1002/bdra.23357 · 2.21 Impact Factor
  • Journal of the American College of Cardiology 03/2015; 65(10):A1520. DOI:10.1016/S0735-1097(15)61520-0 · 15.34 Impact Factor
  • Journal of the American College of Cardiology 03/2015; 65(10):A1518. DOI:10.1016/S0735-1097(15)61518-2 · 15.34 Impact Factor
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    ABSTRACT: Diethylstilbestrol (DES), a synthetic estrogen widely prescribed to pregnant women in the mid-1900s, is a potent endocrine disruptor. Prenatal DES exposure has been associated with reproductive disorders in women, but little is known about its effects on endogenous hormones. We assessed the association between prenatal DES exposure and reproductive hormones among participants from the Harvard Study of Moods and Cycles (HSMC), a longitudinal study of premenopausal women aged 36-45 years from Massachusetts (1995-1999). Prenatal DES exposure was reported at baseline (43 DES exposed and 782 unexposed). Early follicular-phase concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol were measured at baseline and every 6 months during 36 months of follow-up. Inhibin B concentrations were measured through 18 months. We used multivariable logistic and repeated-measures linear regression to estimate odds ratios (OR) and percent differences in mean hormone values (β), respectively, comparing DES exposed with unexposed women, adjusted for potential confounders. DES-exposed women had lower mean concentrations of estradiol (pg/ml) (β=-15.6%, 95% confidence interval (CI): -26.5%, -3.2%) and inhibin B (pg/ml) (β=-20.3%, CI: -35.1%, -2.3%), and higher mean concentrations of FSH (IU/I) (β=12.2%, CI: -1.5%, 27.9%) and LH (IU/I) (β=10.4%, CI: -7.2%, 31.3%), than unexposed women. ORs for the association of DES with maximum FSH>10 IU/I and minimum inhibin B<45 pg/ml - indicators of low ovarian reserve - were 1.90 (CI: 0.86, 4.22) and 4.00 (CI: 0.88-18.1), respectively. Prenatal DES exposure was associated with variation in concentrations of FSH, estradiol and inhibin B among women of late reproductive age.
    Journal of Developmental Origins of Health and Disease 02/2015; 6(03):1-9. DOI:10.1017/S2040174415000082 · 0.77 Impact Factor
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    ABSTRACT: To investigate the association between time to pregnancy (TTP) and adverse birth outcomes. Prospective cohort study. Not applicable. A total of 3,521 singletons born to women aged 18-40 years at cohort entry. None. Selected birth outcomes, including preterm birth (PTB, <37 weeks' gestation), low birth weight (<2,500 g), small for gestational age, large for gestational age, and placental disorders, ascertained from the Danish Medical Birth Registry and Danish National Registry of Patients. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using log-binomial regression, with adjustment for potential confounders and fertility treatment. Multivariable RRs for PTB in relation to TTP of 3-5, 6-11, and ≥12 vs. <3 cycles were 1.59 (95% CI 0.94-2.69), 0.85 (95% CI 0.48-1.50), and 1.57 (95% CI 0.93-2.65). The association was slightly stronger for spontaneous PTB (TTP ≥12 vs. <3 cycles: RR 1.69, 95% CI 0.84-3.42) than for medically indicated PTB (RR 1.39, 95% CI 0.62-3.12). Longer TTPs (≥12 cycles) were associated with increased risks of low birth weight (RR 1.80, 95% CI 0.97-3.35), cesarean delivery (RR 1.64, 95% CI 1.27-2.12), placental disorders (RR 2.21, 95% CI 1.07-4.56), ischemic placental disease (RR 1.56, 95% CI 0.99-2.44), pre-eclampsia (RR 1.45, 95% CI 0.79-2.65), and postpartum hemorrhage (RR 1.58, CI 1.14-2.19), and decreased risks of macrosomia (≥4,500 g; RR 0.63, 95% CI 0.35-1.13) and large for gestational age (RR 0.76, 95% CI 0.58-1.00). Longer TTP showed little association with small for gestational age. In a prospective cohort study of Danish pregnancy planners, delayed conception was a marker for adverse birth outcomes, after accounting for fertility treatment. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
    Fertility and Sterility 02/2015; 103(4). DOI:10.1016/j.fertnstert.2015.01.024 · 4.30 Impact Factor
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    ABSTRACT: What is the magnitude of the association between a woman's gestational age at her own birth and her fecundability (cycle-specific probability of conception)? We found a 62% decrease in fecundability among women born <34 weeks of gestation relative to women born at 37-41 weeks of gestation, whereas there were few differences in fecundability among women born at later gestational ages. One study, using retrospectively collected data on time-to-pregnancy (TTP), and self-reported data on gestational age, found a prolonged TTP among women born <37 gestational weeks (preterm) and with a birthweight ≤1500 g. Other studies of women's gestational age at birth and subsequent fertility, based on data from national birth registries, have reported a reduced probability of giving birth among women born <32 weeks of gestation. We used data from a prospective cohort study of Danish pregnancy planners ('Snart-Gravid'), enrolled during 2007-2011 and followed until 2012. In all, 2814 women were enrolled in our study, of which 2569 had complete follow-up. Women eligible to participate were 18-40 years old at study entry, in a relationship with a male partner, and attempting to conceive. Participants completed a baseline questionnaire and up to six follow-up questionnaires until the report of pregnancy, discontinuation of pregnancy attempts, beginning of fertility treatment, loss to follow-up or end of study observation after 12 months. Among women born <34 gestational weeks, the cumulative probability of conception was 12, 28 and 48% within 3, 6 and 12 cycles, respectively. Among women born at 37-41 weeks of gestation, cumulative probability of conception was 47, 67 and 84% within 3, 6 and 12 cycles, respectively. Relative to women born at 37-41 weeks' gestation, women born <34 weeks had decreased fecundability (fecundability ratio (FR) 0.38, 95% confidence interval (CI): 0.17-0.82). Our data did not suggest reduced fecundability among women born at 34-36 weeks of gestation or at ≥42 weeks of gestation (FR 1.03, 95% CI: 0.80-1.34, and FR 1.13, 95% CI: 0.96-1.33, respectively). Data on gestational age, obtained from the Danish Medical Birth Registry, were more likely to be based on date of last menstrual period than early ultrasound examination, possibly leading to an overestimation of gestational age at birth. Such overestimation, however, would not explain the decrease in fecundability observed among women born <34 gestational weeks. Another limitation is that the proportion of women born before 34 weeks of gestation was low in our study population, which reduced the precision of the estimates. By using prospective data on TTP, our study elaborates on previous reports of impaired fertility among women born preterm, suggesting that women born <34 weeks of gestation have reduced fecundability. The study was supported by the National Institute of Child Health and Human Development (R21-050264), the Danish Medical Research Council (271-07-0338), and the Health Research Fund of Central Denmark Region (1-01-72-84-10). The authors have no competing interests to declare. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
    Human Reproduction 02/2015; 30(4). DOI:10.1093/humrep/dev007 · 4.59 Impact Factor
  • Michael L Jackson, Kenneth J Rothman
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    ABSTRACT: The recently developed test-negative design is now standard for observational studies of influenza vaccine effectiveness (VE). It is unclear how influenza test misclassification biases test-negative VE estimates relative to VE estimates from traditional cohort or case-control studies. We simulated populations whose members may develop acute respiratory illness (ARI) due to influenza and to non-influenza pathogens. In these simulations, vaccination reduces the risk of influenza but not of non-influenza ARI. Influenza test sensitivity and specificity, risks of influenza and non-influenza ARI, and VE were varied across the simulations. In each simulation, we estimated influenza VE using a cohort design, a case-control design, and a test-negative design. In the absence of influenza test misclassification, all three designs accurately estimated influenza VE. In the presence of misclassification, all three designs underestimated VE. Bias in VE estimates was slightly greater in the test-negative design than in cohort or case-control designs. Assuming the use of highly sensitive and specific reverse-transcriptase polymerase chain reaction tests for influenza, bias in the test-negative studies was trivial across a wide range of realistic values for VE. Although influenza test misclassification causes more bias in test-negative studies than in traditional cohort or case-control studies, the difference is trivial for realistic combinations of attack rates, test sensitivity/specificity, and VE. Copyright © 2015. Published by Elsevier Ltd.
    Vaccine 02/2015; 33(11). DOI:10.1016/j.vaccine.2015.01.069 · 3.49 Impact Factor
  • Kenneth J Rothman
    Epidemiology (Cambridge, Mass.) 01/2015; 26(1):1-3. DOI:10.1097/EDE.0000000000000214 · 6.18 Impact Factor
  • Journal of Allergy and Clinical Immunology 01/2015; 135(1):289-290. DOI:10.1016/j.jaci.2014.09.018 · 11.25 Impact Factor
  • Morten Schmidt, Kenneth J Rothman
    International Journal of Cardiology 10/2014; 177(3):1089-1090. DOI:10.1016/j.ijcard.2014.09.205 · 6.18 Impact Factor
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    ABSTRACT: First marketed in the USA in 1996, topiramate (TPM) is an antiepileptic drug later approved for migraine prophylaxis, and in 2012 for weight loss in combination with phentermine. Some studies indicate an elevated prevalence of oral cleft (OC) in infants exposed to TPM in utero. We evaluated the association between TPM use in early pregnancy and the risk of OC. This retrospective cohort study used 1997-2011 automated data from four sources: HealthCore and OptumInsight (commercial insurance claims), Truven Health (Medicaid claims), and Kaiser Permanente Northern California Region (electronic medical records). We compared the prevalence of OCs in infants of women exposed to TPM in the first trimester (TPM cohort) with the prevalence in infants of women formerly exposed to TPM or other antiepileptic drugs (formerly exposed [FE] cohort) and infants of women with similar medical profiles (SMPs) to the TPM cohort that were not exposed to TPM (SMP cohort). To control for confounding, we used stratification and standardization for individual variables and propensity score deciles. The birth prevalence of OCs was 0.36% (7/1945) in the TPM cohort, 0.14% (20/13 512) in the FE cohort, and 0.07% (9/13 614) in the SMP cohort. Standardized by site, the prevalence ratio (PR) for TPM versus FE was 2.5 (95% CI: 1.0-6.0) and for TPM versus SMP was 5.4 (95% CI: 2.0-14.6). Adjustment for covariates one at a time or by propensity score yielded similar results. Consistent with other recent epidemiologic research, first-trimester TPM exposure was associated with an elevated birth prevalence of OC. Copyright © 2014 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 10/2014; 23(10). DOI:10.1002/pds.3612 · 3.17 Impact Factor
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    ABSTRACT: Background Several studies indicate that female obesity increases the risk of spontaneous abortion (SAB). Central adiposity, height, and location of typical weight gain have not been examined as risk factors for SAB.Methods We examined the associations between selected anthropometric factors and risk of SAB among 5132 women enrolled in a Danish Internet-based prospective cohort study of pregnancy planners. We used Cox proportional hazards regression models, with gestational weeks as the time scale, to compute hazard ratios (HRs) of SAB and 95% confidence intervals (CIs).ResultsAfter adjustment for potential confounders, the HRs for SAB among underweight (body mass index (BMI, kg/m2) <20), overweight (BMI: 25–29) and obese (BMI ≥30) women were 1.00 [95% CI: 0.81, 1.24], 0.90 [95% CI: 0.73, 1.09] and 1.23 [95% CI: 0.98, 1.54], respectively, compared with normal weight women (BMI 20–24). The association between obesity and SAB was stronger for early SAB (<8 weeks gestation); HR: 1.34 95% CI: 1.01, 1.77. The HR for height ≥174 cm vs. <166 cm was 0.81 [95% CI: 0.66, 1.00]. Increased waist-to-hip ratio (WHR) was inversely associated with risk of SAB (HR: 0.81; 95% CI: 0.63, 1.05). Waist circumference and location of typical weight gain were not appreciably associated with SAB risk.Conclusions This study confirms previous studies that have shown a small positive association between obesity and SAB risk. Our results suggest that obesity is a stronger risk factor for early pregnancy losses, and that small stature and low WHR are associated with an increased risk of SAB.
    Paediatric and Perinatal Epidemiology 09/2014; 28(5). DOI:10.1111/ppe.12142 · 2.81 Impact Factor
  • Fertility and Sterility 09/2014; 102(3):e350. DOI:10.1016/j.fertnstert.2014.07.1181 · 4.30 Impact Factor
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    ABSTRACT: Background: Prenatal termination of pregnancy may underestimate risks or cause bias in epidemiological studies of birth defects if such studies measure only defects diagnosed postnatally. We aimed to estimate the proportion of all fetuses with birth defects terminated in the second trimester of pregnancy-overall and for specific defects. Methods: The study comprised all pregnancies ending in a singleton birth, miscarriage, or termination of pregnancy for which health care services were sought, as recorded in Danish medical registries between 1 January 2007 and 31 December 2011. Results: Of the 420,090 pregnancies, 307,637 fetuses survived until gestational week 12 or beyond; of these, 296,373 (96%) ended in a live birth or stillbirth and 11,264 (4%) ended in a second-trimester termination. The prevalence of birth defects among live births and stillbirths was 3% (9,790/296,373); the corresponding prevalence among second-trimester-terminated pregnancies was 14% (1,563/11,264). Although only 4% of all pregnancies ended in a second-trimester termination, 14% (1,563/11,353) of pregnancies with birth defects were ended by a second-trimester termination. The groups of birth defects with the highest proportion of second-trimester terminations were defects of the nervous system (347/740; 48%) and abdominal wall (58/149; 39%). For many types of birth defects, however, that proportion was less than 10%. Conclusion: The proportion of terminated pregnancies carrying birth defects is considerably greater than the corresponding proportion for pregnancies that end as live births or stillbirths. The proportion of birth defects unobserved at birth due to second-trimester terminations depends on type of defect and lethality.
    Epidemiology (Cambridge, Mass.) 08/2014; 25(6). DOI:10.1097/EDE.0000000000000163 · 6.18 Impact Factor

Publication Stats

8k Citations
2,263.57 Total Impact Points

Institutions

  • 2015
    • Massachusetts Department of Public Health
      Boston, Massachusetts, United States
  • 1997–2015
    • Boston University
      • • Department of Epidemiology
      • • School of Public Health
      • • Department of Medicine
      • • Section of Preventive Medicine and Epidemiology
      Boston, Massachusetts, United States
  • 2007–2014
    • RTI Health Solutions
      Durham, North Carolina, United States
  • 2013
    • Cardiff University
      Cardiff, Wales, United Kingdom
  • 2009–2013
    • Aarhus University Hospital
      • Department of Clinical Epidemiology
      Århus, Central Jutland, Denmark
    • University of Chichester
      Chichester, England, United Kingdom
    • Brigham and Women's Hospital
      Boston, Massachusetts, United States
  • 2012
    • Denver Health and Hospital Authority
      Denver, Colorado, United States
  • 2009–2012
    • The University of Manchester
      • School of Translational Medicine
      Manchester, ENG, United Kingdom
  • 2008–2012
    • Harvard University
      Cambridge, Massachusetts, United States
    • University of California, Los Angeles
      Los Ángeles, California, United States
  • 2011
    • Karolinska Institutet
      • Institutionen för medicinsk epidemiologi och biostatistik
      Solna, Stockholm, Sweden
    • Health Effects Institute
      Boston, Massachusetts, United States
  • 2006–2011
    • RTI International
      Durham, North Carolina, United States
  • 1980–2011
    • Harvard Medical School
      • Department of Medicine
      Boston, Massachusetts, United States
  • 1989–2007
    • University of Massachusetts Boston
      • Clinical Epidemiology Research and Training Unit
      Boston, Massachusetts, United States
    • University of Massachusetts Amherst
      Amherst Center, Massachusetts, United States
  • 2001–2005
    • Aalborg University Hospital
      Ålborg, North Denmark, Denmark
  • 1981–2004
    • Boston Medical Center
      Boston, Massachusetts, United States
  • 1997–2003
    • Aarhus University
      • Department of Epidemiology and Social Medicine
      Aars, Region North Jutland, Denmark
  • 1999–2002
    • Beverly Hospital, Boston MA
      Beverly, Massachusetts, United States
    • Oulu University Hospital
      Uleoborg, Oulu, Finland
  • 1998
    • University of North Carolina at Chapel Hill
      • Department of Epidemiology
      Chapel Hill, NC, United States
  • 1987
    • University of Massachusetts Medical School
      • Department of Family Medicine and Community Health
      Worcester, Massachusetts, United States