Papers by Margaret Harper
American journal of perinatology, Jan 30, 2017
To compare the risks of adverse maternal and neonatal outcomes associated with spontaneous (SPTB... more To compare the risks of adverse maternal and neonatal outcomes associated with spontaneous (SPTB) versus indicated preterm births (IPTB). A secondary analysis of a multicenter trial of vitamin C and E supplementation in healthy low-risk nulliparous women. Outcomes were compared between women with SPTB (due to spontaneous membrane rupture or labor) and those with IPTB (due to medical or obstetric complications). A primary maternal composite outcome included: death, pulmonary edema, blood transfusion, adult respiratory distress syndrome (RDS), cerebrovascular accident, acute tubular necrosis, disseminated intravascular coagulopathy, or liver rupture. A neonatal composite outcome included: neonatal death, RDS, grades III or IV intraventricular hemorrhage (IVH), sepsis, necrotizing enterocolitis (NEC), or retinopathy of prematurity. Of 9,867 women, 10.4% ( = 1,038) were PTBs; 32.7% ( = 340) IPTBs and 67.3% ( = 698) SPTBs. Compared with SPTB, the composite maternal outcome was more fr...
Obstetric Anesthesia Digest
Preterm pregnancy Vaginal birth after cesarean Trial of labor Cesarean delivery Objective: This s... more Preterm pregnancy Vaginal birth after cesarean Trial of labor Cesarean delivery Objective: This study was undertaken to compare success rates of vaginal birth after cesarean (VBAC) delivery, and uterine rupture as well as maternal/perinatal outcomes between women with preterm and term pregnancies undergoing trial of labor (TOL), and to compare maternal and neonatal morbidities in those women with preterm pregnancies undergoing a TOL versus repeat cesarean delivery without labor (RCD). Study design: Prospective 4-year observational study of women with a singleton gestation and a prior cesarean delivery at 19 academic centers. Clinical characteristics, maternal complications
American journal of perinatology, Jan 19, 2017
Objective The objective was to estimate the optimal screen-positive 1-hour 50 g glucose challenge... more Objective The objective was to estimate the optimal screen-positive 1-hour 50 g glucose challenge test (GCT) threshold for gestational diabetes (GDM) and predictive characteristics of increasing screen-positive GCT threshold values (135–199 mg/dL) for GDM. Study Design It is a secondary analysis of a multicenter mild GDM study. At 24 to 30 weeks' gestation, women with elevated GCT (135–199 mg/dL) completed a diagnostic 3-hour oral glucose tolerance test (OGTT). A novel change-point analysis method was used to compare the GDM rates for the adjacent GCT values, delineating categories of changing risk such that values within categories have equal risk for GDM. Positive (PPV) and negative (NPV) predictive values for GDM were computed for increasing GCT cut-offs. Results In 7,280 women with both GCT (135–199 mg/dL) and OGTT results, 4 GDM risk-equivalent GCT categories were identified with escalations at 144, 158, and 174 mg/dL (all p-values <0.05). The PPV for GDM increased from 33 to 64% as GCT increased from 135 to 199 mg/dL, while the NPV decreased from 80 to 67%. PPVs were only 20% and 61% for risk-equivalent categories of 135 to 143 mg/dL and 174 to 199 mg/dL, respectively. Conclusion Elevated GCT cut-off values between 135 and 143 mg/dL may carry equivalent GDM risk. No threshold GCT value <199 mg/dL alone sufficiently predicts GDM.
Annals of Epidemiology, Mar 31, 2007
Our study aim was to identify factors that may contribute to the racial disparity in pregnancyrel... more Our study aim was to identify factors that may contribute to the racial disparity in pregnancyrelated mortality. METHODS: We examined differences in severity of disease, comorbidities, and receipt of care among 608 (304 African-American and 304 white) consecutive patients of non-Hispanic ethnicity with one of three pregnancy-related morbidities (pregnancy-related hypertension, puerperal infection, and hemorrhage) from hospitals selected at random from a statewide region. RESULTS: African-American women had more severe hypertension, lower hemoglobin concentrations preceding hemorrhage, more antepartum hospital admissions, and a higher rate of obesity. The rate of surgical intervention for hemorrhage was lower among African-Americans, although the severity of hemorrhage did not differ between the two racial groups. More African-American women received eclampsia prophylaxis. After stratifying by severity of hypertension, we found that more African-Americans received antihypertensive therapy. The rate of enrollment for prenatal care was lower in the African-American group. Among women receiving prenatal care, African-American women enrolled significantly later in their pregnancies. CONCLUSIONS: We have identified racial differences in severity of disease, comorbidities, and care status among women with pregnancy-related complications that would place African-Americans at disadvantage to survive pregnancy. These differences are potentially modifiable.
North Carolina Medical Journal, 2010
... NC Med J. 2002;63:76-79. 2. Berg C, Daniel I, Atrash H, Zane S, Bartlett L, eds. Strategies t... more ... NC Med J. 2002;63:76-79. 2. Berg C, Daniel I, Atrash H, Zane S, Bartlett L, eds. Strategies to reduce pregnancy-related deaths: from identification and review to action. Atlanta, GA: Centers for Disease Control and Prevention; 2001. ...
Obstetrical Gynecological Survey, 2009
Data Revues 00029378 V204i1ss S0002937810017849, Aug 19, 2011
Amer J Obstet Gynecol, 2011
American Journal of Obstetrics and Gynecology, Sep 1, 1987
Other investigators have reported that intravenous infusion of synthetic arginine vasopressin int... more Other investigators have reported that intravenous infusion of synthetic arginine vasopressin into fetal lambs increases mean arterial pressure and decreases heart rate. To determine if the bradycardia produced by arginine vasopressin is a reflex response to the increase in blood pressure, we studied the effect of arginine vasopressin infusion on heart rate with and without blocking the increase in blood pressure. We performed 34 experiments in 12 chronically cannulated fetal lambs between 103 and 137 days' gestation. All animals had normal blood gas and pH values. Infusion of arginine vasopressin increased mean arterial pressure 10.1 +/- 1.1 mm Hg and decreased heart rate 50 +/- 8 bpm. Fetal heart rate decreased similarly when arginine vasopressin was infused and the hypertensive response was blocked with nitroprusside or a selective vasoconstrictor antagonist. [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid) 2-(O-methyl)tyrosine] arginine vasopressin. For comparison we also studied five adult nonpregnant ewes. Bradycardia was observed in the adults after infusion of arginine vasopressin alone and when the hypertensive response was blocked with the vasoconstrictor antagonist. We conclude that arginine vasopressin infusion causes a fall in heart rate independent of any increase in blood pressure in both the fetal lamb and the adult sheep.
Obstetrics and Gynecology, Dec 31, 1997
To determine the role of homicide and other injuries in maternal deaths in North Carolina over th... more To determine the role of homicide and other injuries in maternal deaths in North Carolina over the three-year period from 1992 through 1994. Methods: Maternal deaths were identified from death certificates that indicated a maternal death and through an enhanced surveillance system that matches death certificates with live-birth and fetal-death certificates. Deaths were classified as direct, indirect, medically unrelated, or injuryrelated. Patterns of prenatal care were ascertained from the matching live-birth or fetal-death certificates. Maternal death rates for whites and nonwhites were calculated. Results: The most common cause of maternal death was injury, accounting for 62 of the 167 deaths (37%). Homicide was the most common cause of injury-related death (35.5%). The relative risk of maternal death for nonwhites compared with whites was 1.8 (95% confidence interval [CI] 1.6, 2.1). Similarly, their relative risk for injury-related maternal death was 1.7 (95% CI 1.4, 2.2). Conclusion: It is essential to include an analysis of injuryrelated deaths in maternal mortality reporting. As the most common cause of maternal deaths, injury is not limited to densely populated, metropolitan areas. Counseling regarding injury prevention, domestic violence, and depression should be a part of both prenatal and postpartum care.
Data Revues 00029378 V199i6ssa S0002937808013355, Aug 21, 2011
Daily omega-3 fatty acid (FA) supplementation, eicosapentaenoic acid (EPA,1200 mgs) and docosahex... more Daily omega-3 fatty acid (FA) supplementation, eicosapentaenoic acid (EPA,1200 mgs) and docosahexaenoic acid (DHA, 800 mgs), offered no protection from recurrent preterm delivery in a randomized placebo-controlled trial of high risk women receiving weekly 17 alpha-hydroxyprogesterone caproate. Increased levels of EPA and DHA can reduce the production of the potent 2-series prostaglandins derived from arachidonic acid (AA). We conducted this analysis to determine if the supplement altered plasma levels of EPA, DHA or AA. STUDY DESIGN: Blood was collected at enrollment (16-21 weeks' gestation) and again at 25-28 weeks' gestation. Plasma was separated, snap frozen and stored at-70 degrees at a central laboratory until FA determination by gas chromatography. Results were reported as percent of total FA. Wilcoxon test was used to compare the mean change (level at 25-28 weeks minus level at enrollment) in FA between the omega-3 and placebo groups. RESULTS: Of 852 primary study participants, 512 (261 in the omega-3 group and 251 in the placebo group) had results of FA analysis from both enrollment and 25-28 weeks. The mean change in level of EPA, DHA and AA were significantly different between the omega-3 and placebo groups. (Figure) Mean change in plasma levels as % total FA CONCLUSION: Omega-3 supplementation raised EPA and DHA and lowered AA levels in pregnancy.
American Journal of Obstetrics and Gynecology, 2006
Data Revues 00029378 V204i1ss S0002937810017862, Aug 19, 2011
To determine if peripheral blood mononuclear cell (PBMC) production of the anti-inflammatory cyto... more To determine if peripheral blood mononuclear cell (PBMC) production of the anti-inflammatory cytokine interleukin 10 (IL10) and/or the pro-inflammatory cytokine tumor necrosis factor ␣ (TNF␣) differ between high risk women delivering preterm and those delivering at term. STUDY DESIGN: Ancillary to a randomized trial of omega-3 fatty acid (⍀-3) supplementation for the prevention of recurrent preterm birth. Women (nϭ852) with a history of singleton preterm delivery due to either preterm premature rupture of the membranes or preterm labor and currently pregnant with a singleton received weekly injections of 17-alpha hydroxyprogesterone caproate and were randomized to either an omega-3 supplement (2 gram daily) or placebo. PBMC production of IL10 and TNF␣ were measured without (Ϫ) and with (ϩ) stimulation with lipopolysaccharide (LPS) at baseline (B) randomization at 16-22 weeks gestation and again at follow up (FU) at 25-28 weeks gestation. The following values were recorded for both cytokines: BϪ, Bϩ. FUϪ, FUϩ, ⌬B and ⌬FU (difference between LPS stimulated and unstimulated at B and FU) and ⌬⌬ (⌬FU minus ⌬B). RESULTS: A total of 292 and 319 women had paired assays at both baseline and follow up for IL10 ⌬⌬ and TNF␣ ⌬⌬ respectively. The median IL10 ⌬⌬ value for the group delivering at term was positive and higher than that of the group delivering at 35 to 36 weeks. The median IL10 ⌬⌬ value was negative for the group delivering at Ͻ 35 weeks. Because some studies report an association between smoking and IL10 levels we controlled for smoking. The association between IL10 ⌬⌬ levels and preterm birth Ͻ 37 weeks persisted after controlling for smoking, pϭ0.01. There was no significant difference in TNF␣ ⌬⌬ levels between women delivering at term versus preterm, pϭ0.56. CONCLUSIONS: These data suggest that PBMC production of IL10 is depressed as gestation advances in women delivering preterm compared to women delivering at term.
Data Revues 00029378 V199i6ssa S0002937808020206, Aug 21, 2011
Obstetrics and Gynecology
The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians, 2015
To determine whether a reinforcing cerclage (RC) for a short cervix measured after the primary ce... more To determine whether a reinforcing cerclage (RC) for a short cervix measured after the primary cerclage procedure prolonged pregnancy. We conducted a retrospective cohort study of 157 women with singleton gestations who underwent cerclage for standard indications. Women were grouped according to cervical length (CL) at the time of follow-up 1-2 weeks after the initial cerclage placement: ≥25 mm (106 women) and <25 mm with (20 women) or without RC (31 women). Gestational age (GA) at delivery was compared by ANOVA. Survival risk analysis was applied to model GA at delivery adjusted for indication and CL before and after the first cerclage. Women with CL ≥25mm delivered later than women with CL < 25mm after the first cerclage (p < 0.01). RC did not delay delivery for women with CL < 25 mm (p = 0.17) after the primary procedure. Indication for the primary cerclage (p < 0.01) and CL (p < 0.01) after the primary cerclage were the best predictors for GA at delivery. Place...
Obstetrics and Gynecology
OBJECTIVE: To estimate the associations of change in immune response with preterm delivery, omega... more OBJECTIVE: To estimate the associations of change in immune response with preterm delivery, omega-3 supplementation, and fish diet. METHODS: This was an ancillary study to a randomized trial of omega-3 fatty acid supplementation for the prevention of recurrent preterm birth. In vitro maternal peripheral blood mononuclear leukocyte production of the anti-inflammatory cytokine, interleukin-10, and the proinflammatory cytokine, tumor necrosis factor-α, in response to stimulation with lipopolysaccharide, was measured at 16-22 weeks of gestation (baseline) and again at 25-28 weeks of gestation (follow-up) among women with prior spontaneous preterm birth. Changes in concentrations from baseline to follow-up ([INCREMENT]) were compared separately among groups defined by gestational age category at delivery, fish diet history, and omega-3 compared with placebo treatment assignment with Kruskal-Wallis tests. RESULTS: Interleukin-10 [INCREMENT] differed by gestational age category among 292 w...
Obstetrics and gynecology, 2013
North Carolina medical journal
... NC Med J. 2002;63:76-79. 2. Berg C, Daniel I, Atrash H, Zane S, Bartlett L, eds. Strategies t... more ... NC Med J. 2002;63:76-79. 2. Berg C, Daniel I, Atrash H, Zane S, Bartlett L, eds. Strategies to reduce pregnancy-related deaths: from identification and review to action. Atlanta, GA: Centers for Disease Control and Prevention; 2001. ...
North Carolina medical journal
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Papers by Margaret Harper