American Journal of Perinatology (AM J PERINAT )

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: 1.60

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013/2014 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 1.42
Cited half-life 7.20
Immediacy index 0.30
Eigenfactor 0.00
Article influence 0.44
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
    • On author's personal website immediately
    • On 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
    • 'Georg Thieme Verlag' is an imprint of 'Thieme Publishing'
  • Classification
    ​ blue

Publications in this journal

  • [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;
  • [Show abstract] [Hide abstract]
    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;
  • [Show abstract] [Hide abstract]
    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;
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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;
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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;
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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;
  • American Journal of Perinatology 07/2014;
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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;
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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;
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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;
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    ABSTRACT: Objective Securing an arterial line to monitor continuous blood pressure (BP) is difficult in infants. We aimed to reveal the extent of discrepancies between oscillometric and direct BP. Study Design Infants who required continuous BP monitoring were prospectively enrolled. Direct and indirect BP were simultaneously recorded. Disposable BP cuffs matching one-half to two-thirds of the upper arm circumference were used. Results A total of 74 infants were studied (gestational age [GA], 24-42 weeks). The correlation coefficients of systolic, diastolic, and mean arterial BP of indirect and direct measurements were 0.87, 0.82, and 0.84, respectively (p < 0.001). The mean differences in systolic, diastolic, and mean arterial BP (indirect minus direct BP) were 2.2 ± 5.7, - 6.0 ± 5.8, and - 1.3 ± 5.7 mm Hg, respectively. Oscillometric measurements significantly underestimated systolic BP in light-for-gestational-age infants and diastolic BP in infants without fentanyl administration. There were no significant correlations between discrepant BP measurements and edema, vasopressor administration, arterial line location, GA, postnatal age, body weight, pulse rate, or hemoglobin level. In 4.1% of infants, systolic BP increased by 10 to 15 mm Hg at the time of cuff expansion. Conclusion We recommend intra-arterial BP measurement when the BP values seriously influence the therapeutic protocol.
    American Journal of Perinatology 06/2014;
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    ABSTRACT: Objective Congenital nasolacrimal duct obstruction (CNDO) is the most common cause of neonatal epiphora. Persistence can lead to chronic dacryocystitis and amblyopia. This study analyzed the association between the incidence of CNDO and delivery by cesarean section. Study Design This was a retrospective cohort study of 386 children with CNDO (born between 2000 and 2008). The incidence of the delivery mode in patients with CNDO was compared with data from a corresponding population derived from annual birth statistics. Results There was no statistically significant association between the overall cesarean section rate and the incidence of CNDO, but primary cesarean section was significantly more frequent among patients with CNDO (73.15%, p < 0.05). The difference was significant for both genders for the period from 2000 to 2008 (p < 0.05%). The relative risk for CNDO was 1.7-fold increased in children delivered by primary cesarean section. Conclusion Primary cesarean section may be a risk factor for CNDO.
    American Journal of Perinatology 06/2014;
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    ABSTRACT: Objective Obstructive sleep apnea (OSA) is a risk factor for adverse perinatal outcomes. We aimed to test the hypothesis that maternal Mallampati class (MC), as a marker for OSA, is associated with adverse perinatal outcomes. Study Design We performed a retrospective secondary analysis of a prospective cohort of term births (≥ 37 weeks). Fetal anomalies and aneuploidy were excluded. Primary outcome was small for gestational age (SGA). Secondary outcomes included preeclampsia, neonatal cord arterial blood gas pH < 7.10 and < 7.05, base excess < - 8 and < - 12 mEq/L. Outcomes were compared between mothers with low MC airways and high MC airways using logistic regression. Results A total of 1,823 women met the inclusion criteria. No significant differences were found in the risk of SGA (adjusted odds ratio [aOR] 0.9, 95% confidence interval [CI] 0.6-1.2), preeclampsia (aOR 1.2, 95% CI 0.8-1.9) or neonatal acidemia (aOR 0.8, 95% CI 0.3-2.0), between high and low MC. Conclusion High MC is not associated with adverse perinatal outcomes.
    American Journal of Perinatology 06/2014;
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    ABSTRACT: Objective The aim of this article is to evaluate the influence of neonatal factors on kidney size in 5-year-old preterm-born children. Study design Preterm-born children were examined at 5 years with kidney ultrasound. Result A total of 20 children were evaluated. Their gestational age (GA) was 29.3 ± 1.5 weeks, birth weight 1,321 ± 323 g. On Day 28, protein intake was (median, range) 2.8 (1.7-3.6 g/kg) g/kg, protein/total calories ratio 2.8 (range, 1.7-3.3 g/100 kcal) g/100 kcal. At 5 years, their systolic blood pressure was 97 mm Hg (range, 84-115 mm Hg). All had normal estimated glomerular filtration rate. Protein intake on Day 28 and protein/calories ratio on Day 28 were associated with a low total relative renal volume, respectively, β = - 37 ± 15, p = 0.03; β = - 50 ± 19, p = 0.03, after adjustment on GA, neonatal morbidities, and body mass index (multivariate linear regression). Kidney size was not associated with protein intake at 5 years. Conclusion Improving protein prescription in the neonatal period could have an impact on kidney size in childhood in preterm-born children.
    American Journal of Perinatology 06/2014;
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    ABSTRACT: Both "early" (< 16 weeks' gestation) and "late" (> 26 weeks' gestation) presentations of twin-twin transfusion syndrome (TTTS) are rare and challenging complications of monochorionic/diamniotic twin pregnancies. Growing evidence suggests that fetoscopic laser therapy for both "early" and "late" TTTS is feasible, safe, and yields similar outcomes to cases treated between 16 and 26 weeks' gestation. We suggest reevaluation of conventional gestational age guidelines for laser therapy for TTTS.
    American Journal of Perinatology 06/2014;
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    ABSTRACT: Objective The objective of this study was to determine whether the duration and progress of the first stage of labor are different in black compared with white women. Study Design Retrospective cohort study of labor progress among consecutive black (n = 3,924) and white (n = 921) women with singleton term pregnancies (≥ 37 weeks) who completed the first stage of labor. Duration of labor and progression from 1 cm to the next was estimated using interval-censored regression. Labor duration and progress among black and white women in the entire cohort, and stratified by parity, were compared in multivariable interval-censored regression models. Repeated-measures analysis with 9th-degree polynomial modeling was used to construct average labor curves. Results There were no significant differences in duration of the first stage of labor in black compared with white women (median, 4-10 cm: 5.1 vs. 4.9 hours [p = 0.43] for nulliparous and 3.5 vs. 3.9 hours [p = 0.84] for multiparous women). Similarly, there were no significant differences in progression in increments of 1 cm. Average labor curves were also not significantly different. Conclusion Duration and progress of the first stage of labor are identical in black and white women. This suggests similar standards may be applied in the first stage of labor.
    American Journal of Perinatology 06/2014;
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    ABSTRACT: Clinical trials, systematic reviews and guidelines compare beneficial and non-beneficial outcomes following interventions. Often, however, various studies on a particular topic do not address the same outcomes, making it difficult to draw clinically useful conclusions when a group of studies is looked at as a whole. This problem was recently thrown into sharp focus by a systematic review of interventions for preterm birth prevention, which found that among 103 randomised trials, no fewer than 72 different outcomes were reported. There is a growing recognition among clinical researchers that this variability undermines consistent synthesis of the evidence, and that what is needed is an agreed standardised collection of outcomes - a "core outcomes set" - for all trials in a specific clinical area. Recognising that the current inconsistency is a serious hindrance to progress in our specialty, the editors of over 50 journals related to women's health have come together to support The CROWN (CoRe Outcomes in WomeN's health) Initiative.
    American Journal of Perinatology 06/2014;