American Journal of Perinatology Impact Factor & Information

Publisher: Georg Thieme Verlag

Journal description

The American Journal of Perinatology is the definitive forum for today's specialists in obstetrics, neonatology, perinatology, and maternal/fetal medicine. Each issue maintains a critical balance of original, peer-reviewed articles on all aspects of perinatal and critical care management, including maternal risk factors, antenatal diagnosis and intervention, abnormalities and complications of pregnancy, labor and delivery, and congenital and acquired diseases and disorders in newborns.

Current impact factor: 1.91

Impact Factor Rankings

2015 Impact Factor Available summer 2016
2014 Impact Factor 1.905
2013 Impact Factor 1.597
2012 Impact Factor 1.574
2011 Impact Factor 1.316
2010 Impact Factor 1.118
2009 Impact Factor 1.126
2008 Impact Factor 1.158
2007 Impact Factor 0.829
2006 Impact Factor 0.72
2005 Impact Factor 0.685
2004 Impact Factor 0.664
2003 Impact Factor 0.859
2002 Impact Factor 0.603
2001 Impact Factor 0.497
2000 Impact Factor 0.616
1999 Impact Factor 0.71
1998 Impact Factor 0.725
1997 Impact Factor 0.457
1996 Impact Factor 0.45
1995 Impact Factor 0.458
1994 Impact Factor 0.449
1993 Impact Factor 0.424
1992 Impact Factor 0.442

Impact factor over time

Impact factor

Additional details

5-year impact 1.59
Cited half-life 6.40
Immediacy index 0.35
Eigenfactor 0.01
Article influence 0.60
Website American Journal of Perinatology website
Other titles American journal of perinatology
ISSN 0735-1631
OCLC 8875325
Material type Periodical, Internet resource
Document type Journal / Magazine / Newspaper, Internet Resource

Publisher details

Georg Thieme Verlag

  • Pre-print
    • Author cannot archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • Author's post-print or Publisher's version/PDF on author's personal website immediately
    • Author's post-print in Institutional Repository and PubMed Central after 12 months embargo
    • Publisher's version/PDF can be used on author's personal website only
    • Publisher copyright and source must be acknowledged
    • Link to Publisher version ( must be included if article has been published online
    • Publisher last contacted on 31/03/2015
    • 'Georg Thieme Verlag' is an imprint of 'Thieme Publishing'
  • Classification

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective To examine whether time of delivery influences the risk of neonatal morbidity among women with singleton pregnancies. Study Design Secondary analysis of data from the Maternal Fetal Medicine Units Network Factor V Leiden Mutation study. We categorized time of delivery as day (07:00-16:59), evening (17:00-23:59), and overnight (midnight-06:59). Severe neonatal morbidity was defined by at least one of the following: respiratory distress syndrome, transient tachypnea of the newborn, sepsis, seizures, neonatal intensive care admission, or a 5-minute APGAR ≤3. We calculated frequencies of severe neonatal morbidity by time of delivery. Multivariate analysis was performed to determine whether time of delivery was independently associated with severe neonatal morbidity. Results Among 4,087 women, 1,917 (46.9%) delivered during the day, 1,140 (27.9%) delivered in the evening, and 1,030 (25.2%) delivered overnight. We observed no significant differences in the rates of neonatal morbidity between delivery time periods (day: 12.3%; evening: 12.8%; overnight: 12.6%; p = 0.9). No significant association was observed between time of delivery and neonatal morbidity after adjustment for maternal, obstetric, and peripartum factors. Conclusion Our findings suggest that time of delivery is not associated with severe neonatal morbidity.
    American Journal of Perinatology 11/2015; DOI:10.1055/s-0035-1567891
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    ABSTRACT: Objective This study aims to compare how national guidelines approach the management of obesity in reproductive age women. Study Design We conducted a search for national guidelines in the English language on the topic of obesity surrounding the time of a pregnancy. We identified six primary source documents and several secondary source documents from five countries. Each document was then reviewed to identify: (1) statements acknowledging increased health risks related to obesity and reproductive outcomes, (2) recommendations for the management of obesity before, during, or after pregnancy. Results All guidelines cited an increased risk for miscarriage, birth defects, gestational diabetes, hypertension, fetal growth abnormalities, cesarean sections, difficulty with anesthesia, postpartum hemorrhage, and obesity in offspring. Counseling on the risks of obesity and weight loss before pregnancy were universal recommendations. There were substantial differences in the recommendations pertaining to gestational weight gain goals, nutrient and vitamin supplements, screening for gestational diabetes, and thromboprophylaxis among the guidelines. Conclusion Stronger evidence from randomized trials is needed to devise consistent recommendations for obese reproductive age women. This research may also assist clinicians in overcoming one of the many obstacles they encounter when providing care to obese women.
    American Journal of Perinatology 11/2015; DOI:10.1055/s-0035-1567856
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    ABSTRACT: Objective To examine the impact of a rooming-in program for infants at risk of neonatal abstinence syndrome (NAS) on the need for pharmacologic treatment and length of hospitalization. Study Design Our hospital implemented a rooming-in program for newborns at risk of NAS in June 2013. Previously, standard care was to admit these infants to the neonatal intensive care unit. Charts were reviewed to abstract data on at-risk infants born in the 13-month periods prior and subsequent to implementation of rooming-in (n = 24 and n = 20, respectively) and the groups were compared with the outcomes of interest. Result Rooming-in was associated with a reduced need for pharmacologic treatment and shorter length of stay. Conclusion These findings add to an emerging body of evidence on the health care resource utilization benefits associated with rooming-in for infants at risk of NAS. Future studies should evaluate a broader range of outcomes for this model of care.
    American Journal of Perinatology 11/2015; DOI:10.1055/s-0035-1566295
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    ABSTRACT: Objective The aim of the study is to examine the impact of exposure to maternal cigarette smoking on neonatal outcomes of very preterm infants. Study Design A retrospective cohort study examined preterm infants (< 33 weeks gestational age) admitted to the Canadian Neonatal Network centers between 2003 and 2011. Mortality and major morbidities (bronchopulmonary dysplasia, severe intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy) were compared between infants exposed and unexposed to maternal smoking during pregnancy after adjusting for confounders. Results Among 29,051 study infants, 4,053 (14%) were exposed to maternal smoking during pregnancy. Multivariable analysis revealed higher odds of grade 3 or 4 intraventricular hemorrhage or periventricular leukomalacia (adjusted odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.04-1.41) and bronchopulmonary dysplasia (adjusted OR: 1.16, 95% CI: 1.02-1.33) in the smoking group, while mortality, severe retinopathy, and necrotizing enterocolitis were not significantly different. Conclusion Maternal smoking during pregnancy is associated with severe neurological injury and bronchopulmonary dysplasia in preterm infants.
    American Journal of Perinatology 03/2015;

  • American Journal of Perinatology 01/2015;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: The aim of this article is to determine the risk of maternal chorioamnionitis and neonatal morbidity in women with preterm premature rupture of membranes (PPROM) exposed to one corticosteroid course versus a single repeat corticosteroid steroid course. Study design: Secondary analysis of a cohort of women with singleton pregnancies and PPROM. The primary outcome was a clinical diagnosis of maternal chorioamnionitis. Using multivariate logistic regression, we controlled for maternal age, race, body mass index, diabetes, gestational age at membrane rupture, preterm labor, and antibiotic administration. Neonatal morbidities were compared between groups controlling for gestational age at delivery. Results: Of 1,652 women with PPROM, 1,507 women received one corticosteroid course and 145 women received a repeat corticosteroid course. The incidence of chorioamnionitis was similar between groups (single course = 12.3% vs. repeat course = 11.0%; p = 0.8). Women receiving a repeat corticosteroid course were not at increased risk of chorioamnionitis (adjusted odds ratio, 1.28; 95% confidence interval, 0.69-2.14). A repeat course of steroids was not associated with an increased risk of any neonatal morbidity. Conclusion: Compared with a single steroid course, our findings suggest that the risk of maternal chorioamnionitis or neonatal morbidity may not be increased for women with PPROM receiving a repeat corticosteroid course.
    American Journal of Perinatology 12/2014; 32(06). DOI:10.1055/s-0034-1396690
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    ABSTRACT: Objective: The aim of the article is to determine whether maternal body mass index (BMI) influences the beneficial effects of diabetes treatment in women with gestational diabetes mellitus (GDM). Study design: Secondary analysis of a multicenter randomized treatment trial of women with GDM. Outcomes of interest were elevated umbilical cord c-peptide levels (> 90th percentile 1.77 ng/mL), large for gestational age (LGA) birth weight (> 90th percentile), and neonatal fat mass (g). Women were grouped into five BMI categories adapted from the World Health Organization International Classification of normal, overweight, and obese adults. Outcomes were analyzed according to treatment group assignment. Results: A total of 958 women were enrolled (485 treated and 473 controls). Maternal BMI at enrollment was not related to umbilical cord c-peptide levels. However, treatment of women in the overweight, Class I, and Class II obese categories was associated with a reduction in both LGA birth weight and neonatal fat mass. Neither measure of excess fetal growth was reduced with treatment in normal weight (BMI < 25 kg/m(2)) or Class III (BMI ≥ 40 kg/m(2)) obese women. Conclusion: There was a beneficial effect of treatment on fetal growth in women with mild GDM who were overweight or Class I and Class II obese. These effects were not apparent for normal weight and very obese women.
    American Journal of Perinatology 12/2014; 32(01):093-100. DOI:10.1055/s-0034-1374815
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    ABSTRACT: Objective: The aim of this study is to compare fecal calprotectin (FC) levels as measured by a rapid FC assay with those measured by enzyme-linked immunosorbent assay (ELISA) from concurrent stool samples. We also attempted to demonstrate a correlation between elevated rapid assay FC levels and the presence of necrotizing enterocolitis (NEC) and to define a cutoff FC value which could serve as a basis for diagnosing NEC in the future. Study design: Stool samples were collected for FC analysis at 1 and 3 weeks postnatally and whenever there was clinical suspicion of NEC. Results: Rapid assay FC levels were elevated with NEC (3,000 µg/g stool [2075,7875] vs. without (195 µg/g stool [110,440] p < 0.001); and were well correlated with ELISA FC levels (r(2) = 0.89). Conclusion: We present the first data showing that rapid assay FC levels are potentially useful in the bedside diagnosis of NEC.
    American Journal of Perinatology 08/2014; 32(04). DOI:10.1055/s-0034-1384640
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    ABSTRACT: Objective: Over 70% of women with gestational diabetes mellitus (GDM) will develop diabetes mellitus (DM), but only 30% follow through with the recommended postpartum oral glucose tolerance testing (OGTT). HbA1c is approved to diagnose DM, and combined with a fasting plasma glucose it can identify 93% of patients with dysglycemia. We tested the hypothesis that a single blood draw to assess for dysglycemia at the postpartum visit could improve testing rates compared with those required to obtain an OGTT at an outside laboratory. Study design: Prospective cohort study of all women with GDM who delivered between July 2010 and December 2011. When insurance status required testing at an outside laboratory an OGTT was ordered, when insurance allowed testing at our center a random sugar and HbA1c were drawn at the postpartum visit (SUGAR Protocol). Results: Of the 40 women, 36 attended a postpartum visit. In the SUGAR arm, 19 of 19 (100%) were tested versus 9 of 17 (53%) in the OGTT arm; relative risk of testing was 1.9 (95% confidence interval, 1.2-3.0). 36% were glucose intolerant. Conclusion: This pilot study found that an in-office testing model doubled the rate of postpartum testing in this clinic population, and was reasonably sensitive at detecting dysglycemia.
    American Journal of Perinatology 08/2014; 32(03). DOI:10.1055/s-0034-1384637
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    ABSTRACT: Objective: The aim of this study is to examine the hypothesis that prolonged rupture of membranes (PROM) is associated with increased cord blood erythropoietin (EPO) concentrations, proportional to the duration of ruptured membranes. Study design: This study is a prospective, cross-sectional, observational (noninterventional) cohort study of mother-infant pairs. Criteria for inclusion were as follows: active labor with or without ruptured membranes and vaginally delivered neonates. Excluded were infants with major factors known to be associated with a potential increase in fetal erythropoiesis. Results: A total of 40 mother-infant pairs were recruited. EPO was not influenced by duration of ruptured membranes and significantly correlated only with maternal body mass index. Conclusion: Cord blood concentrations of EPO do not appear to be significantly affected by the duration of ruptured membranes. We speculate that erythropoiesis is upregulated in PROM by mechanisms that involve the production of cytokines and are not EPO driven.
    American Journal of Perinatology 07/2014; 32(04). DOI:10.1055/s-0034-1384643
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    ABSTRACT: Until recently, all twin pregnancies were treated in a similar fashion. Ultrasounds were undertaken every 3 to 4 weeks to assess serial fetal growth. Monochorionic (MC) twins comprise only 20% of all twin pregnancies yet unique complications such as twin-twin transfusion syndrome (TTTS), twin reversed arterial perfusion sequence, twin anemia-polycythemia sequence, and selective intrauterine growth restriction can occur. In addition, the in utero death of one twin of a MC pair poses significant risks for death or severe neurologic morbidity in the cotwin. With the exception of discordant growth, these complications are not seen in dichorionic twinning due to the lack of placental anastomoses. In the last two decades, new technologies such as laser photocoagulation for the treatment of severe TTTS and radiofrequency ablation and bipolar cautery for selective reduction have markedly improved outcomes for many of the complications of MC twins. Thus, stratification of "low-risk" twinning (dichorionic twins) versus "high-risk" twinning (MC twins) is paramount to improved outcomes. This can be easily and accurately accomplished with first trimester ultrasound by evaluating the interface of the intertwin membrane with the placenta. This should now be the standard of care for all multiple gestations.
    American Journal of Perinatology 07/2014; 31(S 01). DOI:10.1055/s-0034-1382256
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    ABSTRACT: The underlying etiology of twin-twin transfusion syndrome (TTTS) is unknown, but our growing understanding of the cardiovascular features of TTTS suggests this may be a disease that could respond to transplacental medical therapy. Adjunctive medical therapy in TTTS with the calcium channel blocker nifedipine has been shown to improve recipient survival while having no effect on the donor. There is no significant difference in recipient survival from postoperative day 5 to birth suggesting that the survival benefit is confined to the effects of nifedipine in the perioperative period. Also, there is no significant effect of nifedipine on gestational age at delivery suggesting the survival benefit was unrelated to the tocolytic effects of nifedipine and more likely a result of hemodynamic effects in the recipient twins' cardiovascular system during the perioperative period. TTTS remains poorly understood but there appears to be good evidence suggesting twin-twin hypertensive cardiomyopathy is a large component of the pathophysiology in recipient twins. The initial findings of nifedipine's effectiveness as a targeted medical therapy to address TTTS cardiomyopathy and improve survival of recipient twins opens the door for further research for adjunctive medical therapies in TTTS.
    American Journal of Perinatology 07/2014; 31(S 01). DOI:10.1055/s-0034-1384641

  • American Journal of Perinatology 07/2014; 31(S 01). DOI:10.1055/s-0034-1382775
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    ABSTRACT: Objective: Umbilical cord tissue is naturally available after birth and may provide insight into the health of a newborn. Intraventricular hemorrhage (IVH) is a common complication of prematurity that is suspected to be associated with structural deficiency of the vasculature. We are interested in determining whether umbilical vessel properties could be used to indicate increased risk for IVH. As a first step toward this, we investigated umbilical artery properties as a function of gestational age. Study design: A total of 31 umbilical cord specimens were collected from births ranging from 24 to 40 weeks gestation. Specimens were grouped according to gestational age (less than 25, 26-30, 31-35, and 36-40 weeks). Tension tests were performed on axial and circumferential strips obtained from umbilical arteries. Stiffness, corresponding stretch values, and cross-sectional tissue areas were compared using analysis of variance. Results: Stress-stretch curves displayed no apparent differences across the gestational age range. Statistical analysis of stiffness and stretch values suggested no differences between groups (p > 0.05). Significance was shown between cross-sectional areas of some groups. Conclusions: Mechanical characterization of umbilical arteries suggests that no significant changes in material properties occur in the range of 24 to 40 week gestational age.
    American Journal of Perinatology 06/2014; 32(03). DOI:10.1055/s-0034-1383850
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    ABSTRACT: Objective: The objective of this study was to assess the impact of gestational weight gain outside the Institute of Medicine (IOM) recommendations after the diagnosis of gestational diabetes (GDM) on perinatal outcomes. Materials and methods: This was a retrospective cohort study. Women were classified as gestational weight gain (GWG) within, less than, or greater than IOM recommendations for body mass index as calculated by gestational weight gain per week after a diagnosis of GDM. Outcomes assessed were preeclampsia, cesarean delivery, A2 GDM, birth weight, small for gestational age (SGA), large for gestational age (LGA), macrosomia, and preterm delivery. Groups were compared using analysis of variance and chi-square test for trend, as appropriate. Backward stepwise logistic regression was used to adjust for significant confounding factors. Results: Of 635 subjects, 92 gained within, 175 gained less than, and 368 gained more than IOM recommendations. The risk of cesarean delivery and A2 GDM was increased in those gaining above the IOM recommendations compared with within. For every 1-lb/week increase in weight gain after diagnosis of GDM, there was a 36 to 83% increase in the risk of preeclampsia, cesarean delivery, A2 GDM, macrosomia, and LGA, without decreases in SGA or preterm delivery. Conclusion: Weight gain more than the IOM recommendations per week of gestation after a diagnosis of GDM is associated with adverse pregnancy outcomes.
    American Journal of Perinatology 06/2014; 32(03). DOI:10.1055/s-0034-1383846
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    ABSTRACT: Objective: To determine whether, among women with gestational diabetes (GDM), gestational weight gain above Institute of Medicine (IOM) guidelines increases the risk of large for gestational age (LGA) neonates. Study design: We conducted a retrospective cohort study of singleton term pregnancies with GDM delivered at University of North Carolina Women's Hospital, Chapel Hill, NC from January 2002 to May 2010. We used Poisson regression modeling to estimate LGA risk (birth weight > 90th percentile for gestational age), by body mass index class and adherence to 2009 IOM weight gain guidelines. Women meeting IOM guidelines were the referent group. Final adjusted models included race/ethnicity, medical management of GDM, and gestational age at delivery. Results: Among the 466 women studied, mean ± standard deviation birth weight was 3,526 ± 544 g; 18% (82/466) delivered LGA neonates. Birth weight was greatest among women exceeding, compared with meeting or gaining less than, IOM guidelines (3,703 ± 545 vs. 3,490 ± 505 vs. 3,328 ± 503, p = 0.001). Exceeding IOM guideline was associated with LGA among obese women (adjusted risk ratio 2.62, 95% confidence interval 1.25, 5.50) but not among overweight or normal weight women. Conclusion: Targeting gestational weight gain, a modifiable risk factor, independent of GDM treatment, may decrease LGA risk. Women with GDM may benefit from tailored weight gain recommendations.
    American Journal of Perinatology 06/2014; 32(03). DOI:10.1055/s-0034-1383848