Hyagriv N Simhan

Magee-Womens Hospital, Pittsburgh, Pennsylvania, United States

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Publications (179)714.13 Total impact

  • Francesca L Facco, Hyagriv N Simhan
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    ABSTRACT: To understand the relationship between cervical length and the risk of prematurity in parous women without a history of preterm delivery. Data from 2,998 singleton pregnancies enrolled in a multicenter, observational cohort study were analyzed. We subgrouped the population into the following categories: those with history of at least one spontaneous preterm birth (n=467); nulliparous (n=1,237); and parous with a history of at least one term birth and no previous preterm birth (low-risk history group, n=1,284). The relationship between cervical length (measured between 22 and 22 6/7 weeks of gestation) and preterm birth was examined using logistic regression. Assuming a 40% risk reduction with the use of vaginal progesterone, we calculated the number needed to screen to prevent one preterm birth. An inverse relationship between cervical length and risk of preterm birth was demonstrated for each subgroup. A short cervix (15 mm or less) was identified in only 0.93% of the low-risk group participants compared with 3.4% of the previous preterm birth group participants and 2.1% of nulliparous women. The overall rate of preterm birth was lowest (10.5%) in the low-risk history group; however, the rate of preterm birth for these women with a short cervix was 25%. For a cervical length cutoff of 15 mm or less, preventing one spontaneous delivery before 34 weeks of gestation would require screening 167 (95% confidence interval [CI] 112-317) women with a previous preterm birth, 344 (95% CI 249-555) nulliparous women, and 1,075 (95% CI 667-2,500) women at low risk. Although ultrasonographic short cervix is a risk factor for preterm birth among parous women with exclusively term births, the incidence of a short cervix is very low. The number needed to screen to prevent one preterm birth is considerably greater for women who have a low-risk obstetric history. LEVEL OF EVIDENCE:: II.
    Obstetrics and Gynecology 10/2013; 122(4):858-862. DOI:10.1097/AOG.0b013e3182a2dccd · 4.37 Impact Factor
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    ABSTRACT: Maternal vitamin D deficiency has been linked to fetal growth restriction, but the underlying mechanisms are unclear. We tested the hypothesis that poor maternal 25-hydroxyvitamin D [25(OH)D] was associated with increased risk of placental vascular pathology. Maternal serum 25(OH)D was measured at ≤26 wk of gestation in a random subcohort of term, singleton infants in the Collaborative Perinatal Project (1959-1966; n = 2048). A dichotomous vascular construct was created from the presence of any of 12 pathologies identified on placental examinations, including evidence of placental abruption, infarction, hypoxia, decidual vasculopathy, or thrombosis of fetal vessels (n = 240 cases). The relation between 25(OH)D and vascular pathology was modified by infant sex (P = 0.003). A maternal 25(OH)D concentration ≥80 compared with <50 nmol/L was associated with 49% lower risk of pathology in boys [adjusted OR (95% CI): 0.27, 0.95] after conditioning on study site. No associations were observed between maternal 25(OH)D and pathology in mothers with female offspring. Subsequent analyses showed that, in pregnancies with a female fetus, vascular pathology was associated with a reduced birth-weight z score when the mother's 25(OH)D concentration was <30 nmol/L (β: -0.73; 95% CI: -1.17, -0.30). No association was observed between pathology and birth weight in mothers of female offspring with 25(OH)D concentrations ≥30 nmol/L or in boys, regardless of maternal 25(OH)D status. Our findings suggest complex relations between vitamin D, placental vascular pathology, and birth weight that differ by infant sex. Maternal vitamin D status may be beneficial for male and female offspring through different mechanisms.
    American Journal of Clinical Nutrition 06/2013; 98(2). DOI:10.3945/ajcn.112.055426 · 6.92 Impact Factor
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    ABSTRACT: Objective To determine if the length of fetal long bones (LB) at mid-trimester ultrasound is predictive of small-for-gestational-age (SGA) newborns at term delivery.Methods Retrospective evaluation of 6,781 women between 18 and 24 weeks' gestation at Magee-Womens Hospital (MWH). Gestational age (GA) was confirmed by first- or second-trimester ultrasound and patient's last menstrual period. Data were accrued from the institutional database at MWH. LB measurements were normalized to GA at the time of the ultrasound. The ratio was correlated with the probability of delivering an SGA newborn at term.Results In all, 583 women were identified with an SGA newborn (8.6%). LB-to-GA ratios were associated with the probability of delivering an SGA newborn at term (p < 0.001). There was no single LB that proved to be superior in predicting an SGA newborn.Conclusion There is a significant association between LB-to-GA ratio at midtrimester and the probability of SGA at term.
    American Journal of Perinatology 05/2013; 31(3). DOI:10.1055/s-0033-1345260 · 1.60 Impact Factor
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    L E Tomedi, H N Simhan, L M Bodnar
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    ABSTRACT: AIMS: To estimate the association between serum 25-hydroxyvitamin D concentrations and maternal hyperglycaemia (post-load glucose concentration ≥ 7.5 mmol/l). METHODS: Pregnant women (n = 429; 61% black, 36% obese, 45% smokers) enrolled in a cohort study at <16 weeks gestation. Non-fasting blood samples were assayed for serum 25-hydroxyvitamin D at enrolment. At 24-28 weeks gestation, maternal hyperglycaemia was determined using a 50-g 1-h oral glucose challenge test. RESULTS: A total of 67% of women had 25-hydroxyvitamin D concentrations < 50 nmol/l and 11% had maternal hyperglycaemia. Among smokers, each 23-nmol/l increase in serum 25-hydroxyvitamin D was associated with a reduction in the odds of maternal hyperglycaemia [odds ratio: 0.30 (95% CI: 0.13, 0.68)] after adjustment for parity, race/ethnicity, age, pre-pregnancy BMI, marital status, income, family history of diabetes, and gestational age of gestational diabetes mellitus screening. Among non-smokers, we found no association between early pregnancy vitamin D status and maternal hyperglycaemia. CONCLUSIONS: Smoking status may modify the relationship between poor maternal vitamin D status and maternal hyperglycaemia. This article is protected by copyright. All rights reserved.
    Diabetic Medicine 05/2013; DOI:10.1111/dme.12229 · 3.06 Impact Factor
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    ABSTRACT: BACKGROUND: To establish the unbiased relation between maternal weight gain in pregnancy and perinatal health, a classification for maternal weight gain is needed that is uncorrelated with gestational age. OBJECTIVE: The goal of this study was to create a weight-gain-for-gestational-age percentile and z score chart to describe the mean, SD, and selected percentiles of maternal weight gain throughout pregnancy in a contemporary cohort of US women. DESIGN: The study population was drawn from normal-weight women with uncomplicated, singleton pregnancies who delivered at the Magee-Womens Hospital in Pittsburgh, PA, 1998-2008. Analyses were based on a randomly selected subset of 648 women for whom serial prenatal weight measurements were available through medical chart record abstraction (6727 weight measurements). RESULTS: The pattern of maternal weight gain throughout gestation was estimated by using a random-effects regression model. The estimates were used to create a chart with the smoothed means, percentiles, and SDs of gestational weight gain for each week of pregnancy. CONCLUSION: This chart allows researchers to express total weight gain as an age-standardized z score, which can be used in epidemiologic analyses to study the association between pregnancy weight gain and adverse or physiologic pregnancy outcomes independent of gestational age.
    American Journal of Clinical Nutrition 03/2013; 97(5). DOI:10.3945/ajcn.112.051706 · 6.92 Impact Factor
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    ABSTRACT: Background Although the etiology of preeclampsia is not well understood, it has been suggested that excessive systemic inflammation may lead to oxidative stress, promoting the endothelial dysfunction characteristic of preeclampsia. Few prospective studies have examined the role of infection, an immune system stimulator, as a risk factor for preeclampsia.Methods We conducted a longitudinal study of the relationships between Chlamydia trachomatis (CT), Chlamydophila pneumoniae (CP), cytomegalovirus (CMV), herpes simplex virus (HSV) and preeclampsia among 509 preeclamptic cases and 336 normotensive controls nested within the Danish National Birth Cohort study. Antibodies were analyzed at a first prenatal visit (mean 17.0 weeks) and at a late second/third trimester study visit. Prenatal infections were identified as IgG/IgM seroconversion or a fourfold rise in IgG antibody titers. Multiple regression models were adjusted for maternal age, BMI, smoking status, and time between blood draws.ResultsCT infection was associated with preeclampsia (ORadj 1.6, 95% CI 0.7, 3.6), severe preeclampsia (ORadj 1.8, 95% CI 0.6, 5.3), and preeclampsia resulting in preterm birth (ORadj 1.7, 95% CI 0.6–4.9) or birth of a small for gestational age infant (ORadj 2.1, 95% CI 0.6, 7.5), although CT infection was uncommon (n = 33, 4.0%) and associations were not statistically significant. CP, CMV, and HSV infection were not associated with preeclampsia.Conclusions Women with serological evidence of prenatal CT infection were more likely to develop preeclampsia, although infection was infrequent and confidence intervals were wide. Studies in populations at higher risk for STIs are needed to corroborate this association.
    01/2013; 3(1):28–33. DOI:10.1016/j.preghy.2012.09.002
  • American Journal of Obstetrics and Gynecology 01/2013; 208(1):S44. DOI:10.1016/j.ajog.2012.10.238 · 3.97 Impact Factor
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    ABSTRACT: Objective To compare intra-amniotic inflammation versus microbial invasion of the amniotic cavity (MIAC) as predictors of adverse outcome in preterm labor with intact membranes. Study Design Interleukin-6 (IL-6) was measured in prospectively collected amniotic fluid from 305 women with preterm labor. MIAC was defined by amniotic fluid culture and/or detection of microbial 16S rDNA. Cases were categorized into 5 groups: Infection (MIAC, IL-6>11.3 ng/mL); Severe Inflammation (no MIAC, IL-6>11.3 ng/mL); Mild Inflammation (no MIAC, IL-6 2.6-11.2 ng/mL); Colonization (MIAC, IL-6<2.6 ng/mL); Negative (no MIAC, IL-6<2.6 ng/mL). Results Infection (N=27) and Severe Inflammation (N=36) had similar latency (median <1 day, 2 days, respectively) and similar rates of composite perinatal morbidity and mortality (81%, 72%). Colonization (N=4) and Negative (N=195) had similar outcomes (median latency 23.5, 25 days, composite morbidity and mortality 21%, 25%, respectively). Mild Inflammation (N=47) had outcomes intermediate to Severe Inflammation and Negative (median latency 7 days, composite morbidity and mortality 53%). In logistic regression adjusting for gestational age at enrollment, IL-6 >11.3 and 2.6-11.2 ng/mL, but not MIAC, were significantly associated with composite morbidity and mortality (odds ratio [95% confidence interval] 4.9 [0.6-5.5], 3.1 [1.5-6.4], 1.8 [0.6-5.5], respectively). Conclusions We confirm prior reports that intra-amniotic inflammation is associated with adverse perinatal outcomes whether or not intra-amniotic microbes are detected. Colonization without inflammation appears relatively benign. Intra-amniotic inflammation is not simply present or absent, but has degrees of severity that correlate with adverse outcomes. We propose the designation Amniotic Inflammatory Response Syndrome (AIRS) to denote the adverse outcomes associated with intra-amniotic inflammation.
    American journal of obstetrics and gynecology 01/2013; 210(2). DOI:10.1016/j.ajog.2013.11.032 · 3.97 Impact Factor
  • Jacob Larkin, Hyagriv Simhan
    American Journal of Obstetrics and Gynecology 01/2013; 208(1):S16. DOI:10.1016/j.ajog.2012.10.198 · 3.97 Impact Factor
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    ABSTRACT: OBJECTIVE: In adults one of the major determinants of leukocyte telomere length (LTL), a predictor of age-related diseases and mortality, is cumulative psychosocial stress exposure. More recently we reported that exposure to maternal psychosocial stress during intrauterine life is associated with LTL in young adulthood. The objective of the present study was to determine how early in life this effect of stress on LTL is apparent by quantifying the association of maternal psychosocial stress during pregnancy with newborn TL. STUDY DESIGN: In a prospective study of N=27 mother-newborn dyads maternal pregnancy-specific stress was assessed in early gestation and cord blood PBMCs were subsequently collected and analyzed for LTL measurement. RESULTS: After accounting for the effects of potential determinants of newborn LTL (gestational age at birth, weight, sex and exposure to antepartum obstetric complications), there was a significant, independent, linear effect of pregnancy-specific stress on newborn LTL that accounted for 25% of the variance in adjusted LTL (β=-0.099; p=0.04). CONCLUSIONS: Our finding provides the first preliminary evidence in humans that maternal psychological stress during pregnancy may exert a "programming" effect on the developing telomere biology system that is already apparent at birth, as reflected by the setting of newborn leukocyte telomere length.
    American journal of obstetrics and gynecology 11/2012; 208(2). DOI:10.1016/j.ajog.2012.11.033 · 3.97 Impact Factor
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    ABSTRACT: Background To identify genetic variants contributing to preterm birth using a linkage candidate gene approach. Methods We studied 99 single nucleotide polymorphisms for 33 genes in 257 families with preterm births segregating. Nonparametric and parametric analyses were used. Premature infants and mothers of premature infants were defined as affected cases in independent analyses. Results Analyses with the infant as the case identified two genes with evidence of linkage: CRHR1 (p=0.0012) and CYP2E1 (p=0.0011). Analyses with the mother as the case identified four genes with evidence of linkage: ENPP1 (p=0.003), IGFBP3 (p=0.006), DHCR7 (p=0.009), and TRAF2 (p=0.01). DNA sequence analysis of the coding exons and splice sites for CRHR1 and TRAF2 identified no new likely etiologic variants. Conclusion These findings suggest the involvement of six genes acting through the infant and/or the mother in the etiology of preterm birth.
    Pediatric Research 11/2012; 73(2). DOI:10.1038/pr.2012.166 · 2.84 Impact Factor
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    ABSTRACT: Context:Inconsistent associations between maternal vitamin D status and fetal size have been published in small studies.Objective:Our objective was to examine the association between maternal 25-hydroxyvitamin D [25(OH)D] levels and measures of newborn and placental weight.Design and Setting:We measured maternal 25(OH)D in mothers from the Collaborative Perinatal Project, an observational cohort conducted in 12 U.S. medical centers from 1959 to 1965.Participants:Women delivering singleton, term, live births with 25(OH)D measured at a gestation of 26 wk or less (n = 2146).Main Outcome Measures:Birth weight, ponderal index, placental weight, the placental to fetal weight ratio, and small for gestational age were measured. Hypotheses were formulated after data collection.Results:After confounder adjustment, mothers with 25(OH)D of 37.5 nmol/liter or greater gave birth to newborns with 46 g [95% confidence interval (CI), 9-82 g] higher birth weights and 0.13 cm (0.01-0.25 cm) larger head circumferences compared with mothers with less than 37.5 nmol/liter. Birth weight and head circumference rose with increasing 25(OH)D up to 37.5 nmol/liter and then leveled off (P < 0.05). No association was observed between 25(OH)D and ponderal index, placental weight, or the placental to fetal weight ratio. Maternal 25(OH)D of 37.5 nmol/liter or greater vs. less than 37.5 nmol/liter in the first trimester was associated with half the risk of small for gestational age (adjusted odds ratio 0.5; 95% CI 0.3-0.9), but no second-trimester association was observed.Conclusions:Maternal vitamin D status is independently associated with markers of physiological and pathological growth in term infants. Adequately powered randomized controlled trials are needed to test whether maternal vitamin D supplementation may improve fetal growth.
    The Journal of Clinical Endocrinology and Metabolism 11/2012; DOI:10.1210/jc.2012-3275 · 6.31 Impact Factor
  • Amber Naresh, Hyagriv Simhan
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    ABSTRACT: Preterm premature rupture of membranes (PPROM) and preterm birth are strongly linked to intrauterine inflammation. Bacterial infection is often not identified as the cause. The objective was to examine the amniotic fluid of women with PPROM for viral genomic content, and to correlate with the presence of bacterial infection and markers of intrauterine inflammation. A case series of 13 women with PPROM is presented. Amniocentesis was performed in each of these women. DNA/RNA isolated from amniotic fluid was tested using polymerase chain reaction (PCR) for the presence of herpes simplex virus (HSV)-1 and -2, adenovirus, adeno-associated virus-2 (AAV-2), cytomegalovirus (CMV), parvovirus B19, human papilloma viruses (HPV), and enteroviruses. Maternal and neonatal hospital course and laboratory information, including results of amniotic fluid inflammatory marker testing and bacterial culture, were determined from the medical record. All amniotic fluid samples were negative for HSV-1 and HSV-2, adenovirus, AAV-2, CMV, parvovirus B19, HPV, and enteroviruses. Six of the 13 fluid samples (46%) had positive bacterial cultures, including culture for atypical organisms. In a small series of women, viral infection as assessed by the presence of viral genomic content in the amniotic fluid was not associated with PPROM.
    Journal of Reproductive Immunology 09/2012; 96(1-2). DOI:10.1016/j.jri.2012.08.003 · 2.37 Impact Factor
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    ABSTRACT: Given the unique role of the corticotrophin-releasing hormone (CRH) system in human fetal development, the aim of our study was to estimate the association of birth weight with DNA sequence variation in three maternal genes involved in regulating CRH production, bioavailability and action: CRH, CRH-Binding Protein (CRH-BP), and CRH type 1 receptor (CRH-R1), respectively, in three racial groups (African-Americans, Hispanics, and non-Hispanic Whites). Our study was carried out on a population-based sample of 575 mother-child dyads. We resequenced the three genes in mouse-human hybrid somatic cell lines and selected SNPs for genotyping. A significant association was observed in each race between birth weight and maternal CRH-BP SNP genotypes. Estimates of linkage disequilibrium and haplotypes established three common haplotypes marked by the rs1053989 SNP in all three races. This SNP predicted significant birth weight variation after adjustment for gestational age, maternal BMI, parity, and smoking. African American and Hispanic mothers carrying the A allele had infants whose birth weight was on average 254 and 302 grams, respectively, less than infants having C/C mothers. Non-Hispanic White mothers homozygous for the A allele had infants who were on average 148 grams less than those infants having A/C and C/C mothers. The magnitudes of the estimates of the birth weight effects are comparable to the combined effects of multiple SNPs reported in a recent meta-analysis of 6 GWAS studies and is quantitatively larger than that associated with maternal cigarette smoking. This effect was persistent across subpopulations that vary with respect to ancestry and environment.
    PLoS ONE 09/2012; 7(9):e43931. DOI:10.1371/journal.pone.0043931 · 3.53 Impact Factor
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    ABSTRACT: OBJECTIVE: We sought to evaluate in women with twin gestation the relationship between 17-hydroxyprogesterone caproate (17-OHPC) concentration and gestational age at delivery and select biomarkers of potential pathways of drug action. STUDY DESIGN: Blood was obtained between 24-28 weeks (epoch 1) and 32-35 weeks (epoch 2) in 217 women with twin gestation receiving 17-OHPC or placebo. Gestational age at delivery and concentrations of 17-OHPC, 17-hydroxyprogesterone, progesterone, C-reactive protein (CRP), and corticotrophin-releasing hormone were assessed. RESULTS: Women with higher concentrations of 17-OHPC delivered at earlier gestational ages than women with lower concentrations (P < .001). Women receiving 17-OHPC demonstrated significantly higher (P = .005) concentrations of CRP in epoch 1 than women receiving placebo but CRP values were similar in epoch 2 in both groups. A highly significant (P < .0001) positive relationship was observed between 17-OHPC concentration and progesterone and 17-hydroxyprogesterone concentrations at both epochs. Corticotropin-releasing hormone concentrations did not differ by treatment group. CONCLUSION: 17-OHPC may adversely impact gestational age at delivery in women with twin gestation.
    American journal of obstetrics and gynecology 08/2012; 207(5). DOI:10.1016/j.ajog.2012.08.001 · 3.97 Impact Factor
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    ABSTRACT: Very preterm birth (VPTB) is a leading cause of infant mortality, morbidity and racial disparity in the US. The underlying causes of VPTB are multiple and poorly understood. The California Very Preterm Birth Study was conducted to discover maternal and infant genetic and environmental factors associated with VPTB. This paper describes the study design, population, data and specimen collection, laboratory methods and characteristics of the study population. Using a large, population-based cohort created through record linkage of livebirths delivered from 2000 to 2007 in five counties of southern California, and existing data and banked specimens from statewide prenatal and newborn screening, 1100 VPTB cases and 796 control mother-infant pairs were selected for study (385/200 White, 385/253 Hispanic and 330/343 Black cases/controls, respectively). Medical record abstraction of cases was conducted at over 50 hospitals to identify spontaneous VPTB, improve accuracy of gestational age, obtain relevant clinical data and exclude cases that did not meet eligibility criteria. VPTB was defined as birth at <32 weeks in Whites and Hispanics and <34 weeks in Blacks. Approximately 55% of all VPTBs were spontaneous and 45% had medical indications or other exclusions. Of the spontaneous VPTBs, approximately 41% were reported to have chorioamnionitis. While the current focus of the California Very Preterm Birth Study is to assess the role of candidate genetic markers on spontaneous VPTB, its design enables the pursuit of other research opportunities to identify social, clinical and biological determinants of different types of VPTB with the ultimate aim of reducing infant mortality, morbidity and racial disparities in these health outcomes in the US and elsewhere.
    Paediatric and Perinatal Epidemiology 05/2012; 26(3):250-63. DOI:10.1111/j.1365-3016.2011.01252.x · 2.81 Impact Factor
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    ABSTRACT: Three large randomized controlled trials investigating the efficacy of universal cervical length screening and treatment with vaginal progesterone or cervical cerclage to prevent preterm delivery have been published over the past several years. None of these trials demonstrate proven efficacy for universal cervical length screening and cerclage placement in women with short cervical length. However, universal cervical length screening and treatment with daily vaginal progesterone in women with short cervical length reduces the risk of preterm birth, but large numbers of women must be screened to prevent a relatively small number of preterm deliveries. Issues that should be considered while implementing universal cervical length screening include: (1) standards of quality and reproducibility for transvaginal ultrasound cervical length ascertainment; (2) implications of screening on the application of therapeutic strategies to populations not known to benefit (so-called "indication creep"); and (3) willingness of obstetricians to prescribe vaginal progesterone formulations that are not approved by the US Food and Drug Administration for preterm birth prevention. Optimal strategies to employ cervical ultrasound and progesterone treatment might be revealed by additional studies investigating cervical length cutoffs, frequency of screening, selective screening in higher-risk groups, and the use of transabdominal cervical length screening as a surrogate for transvaginal cervical length screening.
    American journal of obstetrics and gynecology 04/2012; 207(2):101-6. DOI:10.1016/j.ajog.2012.04.021 · 3.97 Impact Factor
  • Steve N Caritis, Hyagriv Simhan
    The Lancet 04/2012; 379(9828):1769-70. DOI:10.1016/S0140-6736(12)60116-0 · 39.21 Impact Factor
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    ABSTRACT: Conventional measures of gestational weight gain (GWG), such as average rate of weight gain, are likely to be correlated with gestational duration. Such a correlation could introduce bias to epidemiological studies of GWG and adverse perinatal outcomes because many perinatal outcomes are also correlated with gestational duration. This study aimed to quantify the extent to which currently used GWG measures may bias the apparent relationship between maternal weight gain and risk of preterm birth. For each woman in a provincial perinatal database registry (British Columbia, Canada, 2000-2009), a total GWG was simulated such that it was uncorrelated with risk of preterm birth. The simulation was based on serial antenatal GWG measurements from a sample of term pregnancies. Simulated GWGs were classified using three approaches: total weight gain (kg), average rate of weight gain (kg/week) or adequacy of GWG in relation to Institute of Medicine recommendations. Their association with preterm birth ≤32 weeks was explored using logistic regression. All measures of GWG induced an apparent association between GWG and preterm birth ≤32 weeks even when, by design, none existed. Odds ratios in the lowest fifths of each GWG measure compared with the middle fifths ranged from 4.4 [95% confidence interval (CI) 3.6, 5.4] (total weight gain) to 1.6 [95% CI 1.3, 2.0] (Institute of Medicine adequacy ratio). Conventional measures of GWG introduce serious bias to the study of maternal weight gain and preterm birth. A new measure of GWG that is uncorrelated with gestational duration is needed.
    Paediatric and Perinatal Epidemiology 03/2012; 26(2):109-16. DOI:10.1111/j.1365-3016.2011.01254.x · 2.81 Impact Factor
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    ABSTRACT: To estimate and compare the risk of morbid perinatal outcomes in pregnancies identified as small for gestational age (SGA) with customized compared with conventional standards of fetal growth. Ultrasound-derived estimates of fetal weight were used to generate a fetal growth trajectory (N=7,510). The gestational age at delivery and pathologic and physiologic variables from 5,072 pregnancies were used to calculate a customized threshold for SGA. In a separate analysis of 32,070 pregnancies, rates of morbid outcomes were compared in participants classified as SGA according to a population-based birth weight standard only (SGApop only), a customized standard only (SGAcust only), and both methods (SGAboth). Eight-hundred seventy-five (2.7%) participants were SGApop only, 1,970 (6.1%) participants were SGAboth, and 609 (1.9%) participants were SGAcust only. The odds ratios of neonatal death in SGApop only and SGAcust only pregnancies were 1.78 (95% confidence interval [CI] 0.2-13.1) and 54.6 (95% CI 29.0-102.8), respectively. Rates of prematurity in the SGApop only and SGAcust only cohorts were 4.8% and 64.5%, respectively. After adjustment for the effect of prematurity, odds ratios of neonatal death in the SGApop only and SGAcust only cohorts were 4.8 (95% CI 0.6-37.0) and 2.9 (95% CI 1.4-6.1), respectively. After adjustment for confounding stemming from premature delivery, there is little difference in the risk of adverse outcomes between SGAcust only and SGApop only participants. Adoption of customized fetal growth standards into clinical practice may not improve the ability to identify pregnancies with increased risk of perinatal morbidity.
    Obstetrics and Gynecology 01/2012; 119(1):21-7. DOI:10.1097/AOG.0b013e31823dc56e · 4.37 Impact Factor

Publication Stats

3k Citations
714.13 Total Impact Points


  • 2003–2015
    • Magee-Womens Hospital
      • • Department of Obstetrics
      • • Magee-Womens Research Institute
      Pittsburgh, Pennsylvania, United States
    • University of Pittsburgh
      • • Division of General Obstetrics and Gynecology
      • • Department of Obstetrics, Gynecology and Reproductive Sciences
      • • Department of Epidemiology
      • • Department of Medicine
      Pittsburgh, Pennsylvania, United States
  • 2011
    • University of Rochester
      • Department of Obstetrics and Gynecology
      Rochester, NY, United States
  • 2010
    • Eunice Kennedy Shriver National Institute of Child Health and Human Development
      Maryland, United States
    • University of Texas Health Science Center at Houston
      Houston, Texas, United States
  • 2008
    • University of Maryland, Baltimore
      Baltimore, Maryland, United States
  • 2007–2008
    • Columbia University
      New York, New York, United States
    • University of Washington Seattle
      • Department of Obstetrics and Gynecology
      Seattle, Washington, United States