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ABSTRACT: To create a fetal size nomogram for use in sub-Saharan Africa and compare the derived centiles with reference intervals from developed countries.
Fetal biometric measurements were obtained at entry to antenatal care (11-22 weeks' gestation) and thereafter at 4-week intervals from pregnant women enrolled in a longitudinal ultrasound study in Kinshasa, Democratic Republic of Congo. The study population comprised 144 singleton gestations with ultrasound-derived gestational age within 14 days of the menstrual estimate. A total of 755 monthly ultrasound scans were included with a mean +/- SD of 5 +/- 1 (range, 2-8) scans per woman. Estimated fetal weight (EFW) was calculated at each ultrasound examination using the Hadlock algorithm. A general mixed-effects linear regression model that incorporated random effects for both the intercept and slope was fitted to log-transformed EFW to account for both mean growth and within-fetus variability in growth. Reference centiles (5(th), 10(th), 50(th), 90(th) and 95(th) centiles) were derived from this model.
Nomograms derived from developed populations consistently overestimated the 50(th) centile EFW value for Congolese fetuses by roughly 5-12%. Differences observed in the 10(th) and 90(th) centiles were inconsistent between nomograms, but generally followed a pattern of overestimation that decreased with advancing gestational age.
In low-resource settings, endemic malaria and maternal nutritional factors, including low prepregnancy weight and pregnancy weight gain, probably lead to lower fetal weight and utilization of nomograms derived from developed populations is not appropriate. This customized nomogram could provide more applicable reference intervals for diagnosis of intrauterine growth restriction in sub-Saharan African populations.
Ultrasound in Obstetrics and Gynecology 04/2009; 34(4):379-86. · 3.01 Impact Factor
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BJOG An International Journal of Obstetrics & Gynaecology 09/2008; 115(9):1076-7. · 3.41 Impact Factor
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ABSTRACT: To examine the association between self reports and biomarkers of stress and placental resistance (measured by Doppler ultrasound of the uterine and umbilical arteries), to determine if restriction of blood flow to the placenta is a mechanism by which stress might affect health during pregnancy.
Eight hundred and seventy-two women had ultrasound examinations of the uterine artery at 15-19 weeks' gestation and the uterine and umbilical arteries at 24-29 weeks, and resistance and pulsatility indices were calculated. Psychosocial stress was measured by telephone interview and self-administered questionnaire using several validated tools twice during the pregnancy. Cortisol and corticotropin-releasing hormone (CRH) were measured twice during the pregnancy. Linear and hierarchical models were used to examine the relationships among reported stress, stress hormones and placental Doppler indices.
The umbilical artery resistance index was higher in younger women, those with less education, those who were single and those who smoked. The uterine artery pulsatility index was higher in women with pre-eclampsia, those living alone, those with high body mass index, and those who gained the least weight during pregnancy. A higher CRH level was associated with small increases in uterine artery pulsatility and umbilical artery resistance indices. Psychosocial measures of stress were not consistently associated with higher placental resistance.
Increased CRH levels may be associated with increased placental resistance. Otherwise, these findings do not support the hypothesis that restriction of blood flow to the fetus is a major mechanism by which stress affects infant health.
Ultrasound in Obstetrics and Gynecology 08/2008; 32(1):23-30. · 3.01 Impact Factor
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ABSTRACT: Maternal malaria and under-nutrition are established risk factors for small-for-gestational-age (SGA) births; however, whether malaria is associated with intrauterine growth restriction (IUGR) is unknown. We investigated IUGR risk among 177 HIV-negative pregnant women enrolled in a longitudinal ultrasound study conducted in Democratic Republic of Congo from May 2005 to May 2006. Malaria infection, maternal anthropometrics, and ultrasound estimated fetal weight were measured monthly. All positive malaria cases were treated and intermittent presumptive therapy (IPTp) provided. Log-binomial regression models for IUGR were fitted using generalized estimating equations to account for statistical clustering of repeat IUGR measurements. Twenty-nine percent of fetuses experienced an episode of IUGR with the majority occurring in the third trimester. The risk of IUGR associated with malaria was greatest after three or more cumulative infections (RR 3.3, 95% CI 1.3-8.2) and was two- to eight-fold higher among women with evidence of under-nutrition. Receiving antimalarial treatment in the previous month (for IPTp or treatment) was significantly protective against IUGR (RR 0.5, 95% CI 0.3-0.7). The interaction observed between malaria and under-nutrition suggests that antenatal programmes in malaria endemic areas should incorporate nutritional screening and supplementation in addition to IPTp.
Epidemiology and Infection 07/2008; 137(2):294-304. · 2.84 Impact Factor
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BJOG An International Journal of Obstetrics & Gynaecology 12/2007; 114(11):1335-6. · 3.41 Impact Factor
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ABSTRACT: To determine whether stress is associated with risk of bacterial vaginosis (BV) in pregnant women.
Prospective cohort study.
The prenatal care clinics at the University of North Carolina. The residents' clinic sees mostly government-insured and uninsured women, and the physicians' clinic sees mostly those with private health insurance.
A total of 897 women gave samples for BV analysis. Study participants were 22% African-American, 68% white; 24% unmarried and 44% nulliparous. More than half had completed college.
Women completed two questionnaires and two interviews reporting stress and psychological aspects of their lives. Measurement scales included the Sarason life events questionnaire, the Cohen perceived stress scale, Spielberger state-trait anxiety, the John Henryism coping style and the Medical Outcomes Study social support inventory. Two stress hormones, corticotrophin-releasing hormone and cortisol, were also measured.
BV at 15-19 and 24-29 weeks of gestation was diagnosed by Gram's stain.
Women in the highest quartile of stress measures, particularly state anxiety (OR=2.0, 95% CI 1.2-3.3), perceived stress (OR=2.4, 95% CI 1.5-3.9) and total life events (OR=2.0, 95% CI 1.3-3.2), had the highest risk of BV. Adjustment for confounders, especially age, race, and income, reduced these associations (state anxiety: OR=1.3, 95% CI 0.7-2.4; perceived stress: OR=1.4, 95% CI 0.8-2.5; total life events: OR=1.3, 95% CI 0.7-2.4). No clear pattern of association was seen between stress hormones and BV.
Few associations between stress and BV were seen after adjustment for confounders.
BJOG An International Journal of Obstetrics & Gynaecology 03/2007; 114(2):216-23. · 3.41 Impact Factor
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ABSTRACT: Despite extensive research on tobacco smoking during pregnancy, few studies address risks among African-American and white women, groups that differ in brand preference and smoking habits. The Pregnancy, Infection, and Nutrition Study is a prospective cohort study that included 2,418 women with detailed information on smoking during pregnancy, including brand, number of cigarettes per day, and changes during pregnancy. We analyzed risk of preterm birth (<37 and <34 weeks' gestation) and small-for-gestational-age deliveries in relation to tobacco use. Pregnant African-American smokers differed markedly from whites in brand preference (95% vs 26% smoked menthol cigarettes) and number of cigarettes per day (1% of African-Americans and 12% of whites smoked 20+ cigarettes per day). Smoking was not related to risk of preterm birth overall, but cotinine measured at the time of delivery was (adjusted odds ratio = 2.2, 95% confidence interval = 1.1-4.5). A clear association and dose-response gradient was present for risk of fetal growth restriction (risk ratio for 20+ cigarettes/day = 2.4, 95% confidence interval = 1.4-4.0). Associations of tobacco use with preterm premature rupture of amniotic membrane resulting in preterm birth were notably stronger than the associations with other types of preterm birth.
Epidemiology 12/2001; 12(6):636-42. · 5.57 Impact Factor
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ABSTRACT: To investigate TCR-CD3zeta expression by cultured T lymphocytes exposed to midtrimester sera from pregnant women in whom preeclampsia developed at term compared with normotensive pregnant control subjects.
Sera obtained at 24 to 28 weeks' gestation from 16 nulliparous women in whom preeclampsia developed at term and from 32 gestational age-matched control subjects without preeclampsia were evaluated for TCR-CD3zeta chain expression with use of Jurkat cells. Subsets of serum samples from 6 women with preeclampsia and 6 control subjects were then evaluated for their ability to induce apoptosis and to suppress interleukin-2 production. Groups were compared by use of the Kruskal-Wallis test, and P <.05 was considered significant.
TCR-CD3zeta chain expression in cultured T lymphocytes was suppressed in approximately 60% of untreated control subjects after incubation with sera from normotensive pregnant women compared with 30% after incubation with sera from women with preeclampsia (P <.001). T-cell apoptosis was significantly higher after incubation with sera from normotensive control subjects, as was the expression of the proapoptotic regulator Bax, compared with sera from women with preeclampsia. Interleukin-2 levels were higher in T cells incubated with sera from women in whom preeclampsia later developed compared with sera from normotensive pregnant women (27.7 ng/mL versus 72.5 ng/mL; P <.001).
Nulliparous women in whom preeclampsia developed did not suppress TCR-CD3zeta levels to the extent of normotensive control subjects, which may be linked to decreased lymphocyte apoptosis. This occurs remotely from the manifestation of clinical disease and suggests a deficiency in a serum factor in preeclampsia that may induce T cell zeta chain suppression in normal pregnancy.
American Journal of Obstetrics and Gynecology 10/2001; 185(4):812-8. · 3.47 Impact Factor
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ABSTRACT: To determine health care resource use by new postmenopausal users of hormone replacement therapy.
We used the Saskatchewan Health administrative databases, which include a health insurance registration file, a cancer registry, and files with data on outpatient prescription drugs, hospital services, and physician services. Our population included postmenopausal women aged 55 years and over with intact uteri taking hormone replacement therapy for long-term prevention benefits, and an equal number of postmenopausal women with intact uteri with no medical contraindications to hormone replacement therapy but who did not use the therapy during the study period.
The population in our analysis included 2632 women with new episodes of hormone replacement therapy, all with at least 3 years of follow-up. Only 42% of new hormone replacement therapy users continuously took HRT during the first year after initiation of their first new episode; a third of these were full-year users in the second year. New users of hormone replacement therapy over a 6-year follow-up period had significantly higher rates of medical care contact for diagnoses of menopausal disorders in the first year of HRT compared with subsequent years. We also found slightly elevated numbers of visits to primary care physicians and obstetrician-gynecologists and slightly increased use of endometrial biopsies and dilation and curettage procedures in the first year of hormone replacement therapy, compared with subsequent years.
New users of hormone replacement therapy had higher rates of medical care for menopausal disorders in their first year of therapy compared with rates in subsequent years. After discontinuing hormone replacement therapy, utilization of medical care decreased dramatically.
American Journal of Obstetrics and Gynecology 09/2001; 185(2):318-26. · 3.47 Impact Factor
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ABSTRACT: Frequency of eating or meal patterns during pregnancy may be a component of maternal nutrition relevant to pregnancy outcome. To identify meal patterns of pregnant women and investigate the relation between these meal patterns and preterm delivery, the authors performed an analysis using data from the Pregnancy, Infection, and Nutrition Study (n = 2,065). Women recruited from August 1995 to December 1998 were categorized by meal patterns on the basis of their reported number of meals (breakfast, lunch, and dinner) and snacks consumed per day during the second trimester. An optimal pattern was defined according to the Institute of Medicine recommendation of three meals and two or more snacks per day. In this population, 72 percent of the women met this recommendation, and 235 delivered preterm. Women who consumed meals/snacks less frequently were slightly heavier prior to pregnancy, were older, and had a lower total energy intake. In addition, these women had a higher risk of delivering preterm (adjusted odds ratio = 1.30, 95 percent confidence interval: 0.96, 1.76). There was no meaningful difference in the risk by early versus late preterm delivery, but those who delivered after premature rupture of the membranes (adjusted odds ratio = 1.87, 95 percent confidence interval: 1.02, 3.43) had a higher risk than those who delivered after preterm labor (adjusted odds ratio = 1.11, 95 percent confidence interval: 0.64, 1.89). This study supports previous animal model work of an association between decreased frequency of eating and preterm delivery.
American Journal of Epidemiology 05/2001; 153(7):647-52. · 5.22 Impact Factor
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ABSTRACT: To examine the association between sexual activity during late pregnancy and preterm delivery.
Women at least 16 years old and carrying singleton fetuses were recruited between 24 and 29 weeks' gestation from prenatal clinics in central North Carolina. They were interviewed by telephone about sexual activity before and during pregnancy. One hundred eighty-seven women delivered between 29 and 36 weeks and had a follow-up interview after delivery. Four hundred nine women who were selected randomly from the cohort served as controls and had a follow-up interview between 29 and 36 weeks (mean gestational age 39.2 weeks).
Intercourse during late pregnancy was associated with a reduced risk of preterm delivery. The conditional odds ratio (OR) was 0.34 and 95% confidence interval (CI) 0.23, 0.51 for preterm delivery within 2 weeks after intercourse. Similar decreased risk for preterm delivery was found with recent female orgasm. Adjusting for race, age, education, and living with a partner had little effect on results. Cases were more likely than controls to report poorer health, medical reasons for reducing sexual activity, less interest in sex, and receipt of advice to restrict sexual activity during pregnancy. Results did not differ substantially according to presence or absence of bacterial vaginosis at 28 weeks.
These data provide evidence against the hypothesis that sexual activity generally increases risk of preterm delivery between 29 and 36 weeks. However, we cannot exclude the possibility that a small subgroup of susceptible women might have adverse consequences of sexual activity.
Obstetrics and Gynecology 03/2001; 97(2):283-9. · 4.73 Impact Factor
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N D Berkman, J M Thorp,
K E Hartmann,
K N Lohr,
A E Idicula,
M McPheeters,
N I Gavin,
T S Carey,
S Tolleson-Rinehart,
A M Jackman,
V Hasselblad,
E C Puckett
Evidence report/technology assessment (Summary) 11/2000;
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ABSTRACT: The purpose of this study was to investigate the association between bacterial vaginosis (BV) and cervical dilation and effacement, as measures of impending preterm delivery. The Pregnancy, Infection, and Nutrition Study collected genital tract specimens and documented cervical change from 807 eligible women between 24 and 29 weeks' gestation. BV was assessed with Nugent-scored vaginal smears, and analyzed in relation to cervical measurements. At 24-29 weeks' gestation, <7% of women had a dilated cervix, 31% had a cervix < or =2 cm, and 17.3% had BV. Unadjusted analyses found no associations between BV and cervical measurements. Adjusted logistic regression suggested an association between BV and cervical effacement among women with a sexually transmitted disease (STD) earlier in pregnancy (odds ratio = 1.9, 95% CI 0.8-4.3). Stratified analyses for BV/dilation also suggested interaction with STDs. Overall, BV was not association with cervical dilation or effacement at 24-29 weeks' gestation.
American Journal of Perinatology 02/2000; 17(2):83-8. · 1.32 Impact Factor
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Clinical Obstetrics and Gynecology 01/2000; 42(4):820-35. · 1.93 Impact Factor
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ABSTRACT: Although pregnancy does not increase the prevalence of ASB in women, it does enhance the progression rate from asymptomatic to symptomatic disease. Furthermore, ASB is associated with preterm delivery. Given the fact that identification and eradication of ASB in pregnant women can lower the likelihood of pyelonephritis and prevent preterm delivery, every gravida should be systematically screened for ASB and appropriately treated. In the authors' opinion, a first-trimester urine culture remains the screening test of choice; reliance on symptoms to prompt screening is inadequate because the state of pregnancy can provoke frequency and nocturia. Multiple antibiotic regimens for ASB are safe during pregnancy and effective.
Urologic Clinics of North America 12/1999; 26(4):779-87. · 1.82 Impact Factor
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ABSTRACT: Pregnancy and childbirth are commonly thought to be associated with the development of urinary incontinence and lower urinary tract symptoms. The purpose of this study was to assess the relationship, if any, between pregnancy and the development of lower urinary tract symptoms. Study Design: A prospective study of lower urinary tract symptoms was carried out in a cohort of pregnant women who answered a series of symptom questionnaires and kept a 24-hour bladder chart on which frequency of urination and volumes voided were recorded throughout pregnancy and for 8 weeks after birth.
A total of 123 women participated in the study. Mean daily urine output (P =.01) and the mean number of voids per day (P =.01) increased with gestational age and declined after delivery. Episodes of urinary incontinence peaked in the third trimester and improved after birth (P =.001). White women had higher mean voided volumes and fewer voiding episodes than did black women. Ingestion of caffeine was associated with smaller voided volumes and greater frequency of urination.
Pregnancy is associated with an increase in urinary incontinence. This phenomenon decreases in the puerperium. Pregnancy and childbirth trauma are important factors in the development of urinary incontinence among women. These findings warrant further investigation.
American Journal of Obstetrics and Gynecology 09/1999; 181(2):266-73. · 3.47 Impact Factor
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ABSTRACT: We identified maternal demographic, behavioral, and medical history factors that predict bacteriuria (that is, symptomatic and asymptomatic urinary tract infection) at prenatal care initiation. We applied logistic regression modeling to data from all prenatal care recipients who delivered during 1990-1993 and resided in selected North Carolina counties (N = 8037), omitting those with diabetes mellitus, human immunodeficiency virus, or structural urologic abnormalities. The two strongest predictors of bacteriuria at prenatal care initiation were an antepartum urinary tract infection prior to prenatal care initiation (for whites, adjusted prevalence odds ratio (POR) = 2.5, 95% CI 0.6-9.8; for blacks, POR = 8.8, 95% CI 3.8-20.3) and a pre-pregnancy history of urinary tract infection (POR = 2.1, 95% CI 1.4-3.2). For white women only, education beyond high school and age > or =30 years were inversely associated (POR < or = 0.6). Sickle cell hemoglobin nearly doubled the prevalence odds for bacteriuria among African-Americans (POR = 1.9, 95% CI 1.0-3.5), whereas African-Americans with normal hemoglobin had reduced prevalence odds compared with whites (POR = 0.6, 95% CI 0.4-0.9). This study suggests predictors not considered before, including race controlling for sickle cell disease or trait and antepartum urinary tract infections prior to prenatal care.
Epidemiology 05/1999; 10(3):282-7. · 5.57 Impact Factor
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ABSTRACT: To examine the relation between cervical dilatation and length and the risk of spontaneous preterm birth, including its subtypes preterm labor and preterm premature rupture of membranes (PROM).
Cervical dimensions assessed by clinical examination were recorded prospectively at 24-29 weeks' gestation in 871 subjects with singleton pregnancies who were followed to delivery. Relative risks (RRs) of preterm birth, preterm labor, and preterm PROM were calculated for clinically distinguishable categories of cervical dilatation and length and for cervical score (length minus dilatation). Regression analysis was used to adjust for confounding. Time to delivery from baseline examination was summarized using survival analysis.
There were 73 spontaneous preterm births (8.3%), 46 preterm labors and 27 cases of preterm PROM. All cervical measurements were associated with increased risks of preterm birth, with increasing abnormality more strongly predictive of risk. The adjusted RR for preterm birth with dilatation of at least 0.5 cm was 2.9 (95% confidence interval [CI] 1.2, 7.3); for length of 1.5 cm or less, the RR was 2.1 (95% CI 1.0, 4.5), and for cervical score less than 2.0, the RR was 2.8 (95% CI 1.4, 5.6). The association with cervical measurements was stronger for preterm PROM than for preterm labor, although precision was limited. These measurements had high specificity (93-99%) and low sensitivity (8-20%) for predicting preterm birth.
In asymptomatic women at 24-29 weeks' gestation, greater cervical dilatation and shorter length were associated with increased risk of spontaneous preterm delivery, particularly preterm PROM.
Obstetrics and Gynecology 05/1999; 93(4):504-9. · 4.73 Impact Factor
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ABSTRACT: To investigate the relationship between bacterial vaginosis during pregnancy and black race/ethnicity.
Gram staining was used to evaluate vaginal flora in 842 women at 24 to 29 weeks' gestation.
Overall, 22.3% of blacks and 8.5% of whites had bacterial vaginosis. Vaginal pH and flora differed significantly by race/ethnicity; blacks were more likely to have pH > or = 4.5, no lactobacilli, small gram-variable and -negative rods, and Mobiluncus compared with whites (odds ratios 1.6, 1.5, 1.4, and 10.6, respectively). Quantity of morphotypes also differed, especially for Mobiluncus. Among women with Mobiluncus present (12.0% of blacks and 1.3% of whites), 73.3% of blacks compared with 40.0% of whites had the highest level. Adjustment for sociodemographics, sexual activity, sexually transmitted diseases, health behavior, and sexual hygiene did not explain these differences.
We observed race/ethnicity differences in vaginal flora ecology. These differences may ultimately play a role in the larger proportion of preterm deliveries among black women compared with white women.
Sex Transm Dis 03/1999; 26(2):96-102. · 2.87 Impact Factor
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ABSTRACT: We describe the study design and patterns of participation for a cohort study of preterm delivery, focused on genital tract infections, nutrition, tobacco use, illicit drugs and psychosocial stress. Women are recruited at 24-29 weeks' gestation from prenatal clinics at a teaching hospital and a county health department. We recruited 57% of the first 1843 eligible women; 29% refused and 8% could not be contacted. White women were somewhat more likely to participate than African-American women (61% vs. 54% respectively). More notable differences were found comparing teaching hospital and health department clinics (71% vs. 47% participation respectively), with the health department clinic having a greater proportion refuse (24% vs. 33%) and more women who could not be contacted (4% vs. 11%). Participation was affected only minimally by day or timing of recruitment, but inability to contact diminished substantially as the study continued (13-0%). Refusals were largely unrelated to patient attributes. Lower education predicted inability to contact. Risk of preterm delivery was 14% among recruited women, 10% among women who refused, and 15% among women whom we were not able to contact, demonstrating that, overall, risk status was not lower among recruited women.
Paediatric and Perinatal Epidemiology 02/1999; 13(1):114-25. · 2.31 Impact Factor
