Melissa Swain

The preterm prediction study: Maternal stress is associated with spontaneous preterm birth at less than thirty-five weeks' gestation ☆ ☆☆ ★

OBJECTIVE Our purpose was to determine whether various measures of poor psychosocial status in pregnancy are associated with spontaneous preterm birth, fetal growth restriction, or low birth weight. STUDY DESIGN Anxiety, stress, self-esteem, mastery, and depression were assessed at 25 to 29 weeks in 2593 gravid women by use of a 28-item Likert scale. Scores for each psychosocial subscale were determined, and an overall psychosocial score was calculated. Scores were divided into quartiles, and the lowest quartile scores were used to define poor psychosocial status. The percent spontaneous preterm birth, low birth weight, and fetal growth restriction in women with low and high psychosocial scores were compared. Logistic regression analyses provided the odds ratios and 95% confidence intervals. RESULTS Analyses revealed that stress was significantly associated with spontaneous preterm birth and with low birth weight with odds ratios of 1.16, p = 0.003, and 1.08, p = 0.02, respectively, for each point on the scale. A low score on the combined scale or on any subscale other than stress did not predict spontaneous preterm birth, fetal growth restriction, or low birth weight. After multivariate adjustment was performed for psychosocial status, substance use, and demographic traits, black race was the only variable significantly associated with spontaneous preterm birth, fetal growth restriction, and low birth weight; stress and low education were associated with spontaneous preterm birth and low birth weight. CONCLUSION Stress was associated with spontaneous preterm birth and low birth weight even after adjustment for maternal demographic and behavioral characteristics. Black race continues to be a significant predictor of spontaneous preterm birth, fetal growth restriction, and low birth weight even after adjustment for stress, substance use, and other demographic factors.

Follow-up of Children Exposed In Utero to 17 α-Hydroxyprogesterone Caproate Compared With Placebo

OBJECTIVE: To assess whether there are evident adverse effects of 17 &agr;-hydroxyprogesterone caproate after in utero exposure. METHODS: This study evaluated surviving children of mothers who participated in a multicenter placebo-controlled trial of weekly intramuscular 17 &agr;-hydroxyprogesterone caproate, with a 2:1 allocation to 17 &agr;-hydroxyprogesterone caproate and placebo, respectively. The guardian was interviewed about the child’s general health. Children underwent a physical examination and developmental screen with the Ages and Stages Questionnaire. Gender-specific roles were assessed with the Preschool Activities Inventory. RESULTS: Of 348 eligible surviving children, 278 (80%) were available for evaluation (194 in the 17 &agr;-hydroxyprogesterone caproate group and 84 in the placebo group). The mean age at follow-up was 48 months. No significant differences were seen in health status or physical examination, including genital anomalies, between 17 &agr;-hydroxyprogesterone caproate and placebo children. Scores for gender-specific roles (Preschool Activities Inventory) were within the normal range and similar between 17 &agr;-hydroxyprogesterone caproate and placebo groups. CONCLUSION: 17 &agr;-hydroxyprogesterone caproate seems to be safe for the fetus when administered in the second and third trimesters. LEVEL OF EVIDENCE: II

Systemic tocolysis for premature labor is associated with an increased incidence of pulmonary edema in the presence of maternal infection

Our hypothesis is that systemic tocolysis of patients in premature labor is associated with a higher incidence of pulmonary edema in the presence of maternal infection. Over a 64-month period, medical records of all patients with a diagnosis at discharge of pulmonary edema or congestive heart failure were reviewed. There were 27 cases of pulmonary edema, 16 of which (59.3%) were associated with treatment of preterm labor. The incidence of pulmonary edema in patients receiving systemic tocolysis for treatment of preterm labor was significantly higher than that in our general obstetric population (3.04% versus 0.05%). Of the 527 patients receiving tocolysis, there was evidence of maternal infection in 52. The incidence of pulmonary edema was higher in the presence of maternal infection than in its absence (11/52 or 21% versus 5/475 or 1%, p = 0.0000). We conclude that there is a very strong association between the development of pulmonary edema and the presence of maternal infection in patients being treated for premature labor with systemic tocolysis.

Natural history of cervical funneling in women at high risk for spontaneous preterm birth

OBJECTIVE: To estimate the natural history of funneling in the second trimester by transvaginal ultrasonograms and whether funneling increases the risk of spontaneous birth. METHODS: Secondary analysis of a blinded, multi-center observational study of women with at least one prior spontaneous preterm birth at 16.0–31.9 weeks who subsequently carried singleton gestations. Cervical length, funneling (membrane prolapse greater than or equal to 5 mm), funnel shape, and dynamic changes were recorded at 16–18 weeks, and then every 2 weeks until 23.9 weeks. Managing obstetricians were blinded to the ultrasonography results. The primary outcome was gestational age at delivery. RESULTS: Five hundred ninety scans were performed in 183 women, of which 60 (33%) had funneling observed on at least one of the serial evaluations. These 60 women delivered at an earlier gestational age at delivery than the 123 women without funneling (31.7±7.9 weeks compared with 36.9±4.4 weeks; P<.001). In the 60 women with funneling on at least one evaluation, the progression over time of internal os cervical anatomy from a “T” to a “V” to a “U” shape was associated with earlier gestational age at delivery, whereas resolution of “V” shape funnels was associated with term delivery. Women with a shortened cervical length less than 25 mm (n=60) had a similar gestational age at birth with or without funneling (30.6±8.0 weeks compared with 31.9±6.6 weeks; P=.59). After controlling for the shortest observed cervical length, largest funnel percent was not a significant independent risk factor. CONCLUSION: The natural history of second-trimester funneling has significant variability and a significant association with earlier gestational age at delivery. As an independent finding, funneling does not add appreciably to the risk of early gestational age at delivery associated with a shortened cervical length. LEVEL OF EVIDENCE: II

Interrelationship and clinical significance of increasedresistance in the uterine arteries in patients with hypertension or preeclampsia or both

OBJECTIVES This study was designed to evaluate the clinical significance of the Doppler flow velocity waveform analysis of the two uterine arteries on an individual basis and in combination expressed as the mean uterine artery. STUDY DESIGN We evaluated uterine artery resistance by means of continuous wave Doppler ultrasonography in 123 pregnant women with chronic hypertension, preeclampsia, or both. The placental location was determined by real-time ultrasonography. Clinical outcomes were compared according to uterine artery abnormalities. The Doppler flow studies were not used in patient management. RESULTS In patients with unilateral placentas (n = 67) the placental uterine artery was found to be a better predictor of poor pregnancy outcome than the nonplacental artery and the mean of the two arteries. There was a strong degree of correlation between abnormal nonplacental uterine artery and abnormal mean of uterine artery (r = 0.75, p less than 0.001), and there was a moderate degree of correlation between abnormal placental uterine artery and abnormal mean uterine artery (r = 0.46, p less than 0.001). Uterine artery discordance (left-right uterine artery systolic/diastolic ratio) was mostly the result of an abnormal nonplacental uterine artery (r = 0.74, p less than 0.0001) and not the result of an abnormal mean uterine artery (r = 0.44, p less than 0.003); the degree of discordance did not relate to pregnancy outcome. Unilateral placental location was associated with longer stays in neonatal intensive care units and more perinatal deaths. CONCLUSION Because of the differences between the two uterine arteries, we conclude that for proper interpretation of uterine artery flow velocity waveforms, the placental location should be known and each vessel analyzed individually.

Variable decelerations during nonstress tests are not a sign of fetal compromise

An examination of 908 fetal heart rate tests of 418 consecutive patients revealed brief variable decelerations in more than 50.7% of the patients. Although an association existed with nuchal cord location found at delivery, no association existed between these variable decelerations and fetal heart rate decelerations during labor, low Apgar scores at birth, or birth weight. We find no evidence to suggest that these brief variable decelerations are a sign of fetal compromise or an indication for obstetric intervention.

Effect of coitus on recurrent preterm birth.

OBJECTIVE: To estimate the impact of sexual behavior on the risk of recurrent spontaneous preterm birth at less than 37 weeks of gestation. METHODS: This is a secondary analysis of a multicenter, blinded observational study of endovaginal sonographic examinations performed at 16–18 weeks of gestation on 187 women with singleton gestations who were at high risk for recurrent spontaneous preterm birth (prior spontaneous preterm birth at < 32 weeks of gestation). At the time of enrollment, each woman was interviewed by a research nurse with regard to her sexual history. The patient was asked about the number of sexual partners in her lifetime, the number of sexual partners since the start of her pregnancy, and, on average, the frequency of intercourse per week in the preceding month. RESULTS: A total of 165 pregnancies were available for this analysis. The population incidence of spontaneous preterm birth at less than 37 weeks of gestation in the study pregnancy was 36%. An increasing number of sexual partners in a womans lifetime was associated with an increased risk of spontaneous preterm delivery (one partner 19%, 2–3 partners 29%, ≥ 4 partners 44%, P = .007), whereas the number of sexual partners since the start of pregnancy was not (P = .42). Women who reported infrequent sexual intercourse during early pregnancy had an incidence of recurrent spontaneous preterm birth of 28% compared with 38% in those women who reported some intercourse (P = .35). CONCLUSION: Self-reported coitus during early pregnancy was not associated with an increased risk of recurrent preterm delivery. There was an association between increasing number of sexual partners in a womans lifetime and recurrent preterm delivery. LEVEL OF EVIDENCE: II-2

Vascular and uterine responses to dobutamine and dopamine in the gravid ewe

Dopamine, a naturally occurring catecholamine precursor of norepinephrine, has been used in the treatment of cardiogenic shock. Following intravenous administation it increases cardiac output, blood pressure, and renal blood flow. Dobutamine is a directly acting inotropic agent which increases myocardial contractility without significantly changing blood pressure. This study was devised to compare the effects of these two drugs on uterine blood flow (UBF), uterine tonus (UT), mean arterial blood pressure (MAP), and heart rate (HR). Chronically instrumented pregnant ewes near term were infused with differet concentrations of dopamine and dobutamine while HR, MAP, UT and UBF were recorded continuously. Dopamine produced a decrease in UBF and an increase in MAP and UT while the HR response was variable. Dobutamine administration resulted in a marked increase in HR and a decrease in UBF, while MAP and UT remained essentially unchanged. Uterine vascular resistance increased with both drugs during high-dosage administration, but the rise was more pronounced following dopamine infusion. Since dobutamine exhibits less alpha-adrenergic activity than dopamine this drug would seem to be preferred when an inotropic agent is required for treatment of the pregnant patient.

Second-trimester cervical sonography: features other than cervical length to predict spontaneous preterm birth.

OBJECTIVE: To estimate whether cervical and lower uterine segment characteristics other than cervical length and funneling predict recurrent preterm birth. METHODS: We conducted a secondary analysis of a multicenter, blinded observational study of 181 women with singletons and prior spontaneous preterm births. Endovaginal ultrasonic examinations were performed at 2-week intervals between 16 0/7 weeks and 23 6/7 weeks of gestation. Cervical canal contour (straight/curved), cervical position (horizontal/vertical), posterior cervical width, lower uterine segment thickness, vascularity, endocervical canal dilation, with or without associated membrane prolapse and chorioamnion visible at the internal os, were systematically assessed. RESULTS: At the initial sonogram (16 0/7–18 6/7 weeks), membranes visible overlying the internal os (relative risk 1.9, confidence interval [CI] 1.2, 3.1) and canal dilation of 2–4 mm (relative risk 2.6, CI 1.4, 4.7) were significant predictors of spontaneous preterm birth of less than 35 weeks in univariate analyses. Only canal dilation remained statistically significant after controlling for cervical length (odds ratio 5.5, CI 1.1, 28.6). CONCLUSION: Endocervical canal dilation of 2–4 mm during second-trimester endovaginal sonography was associated with an increased risk of recurrent preterm delivery independent of cervical length. LEVEL OF EVIDENCE: II-2

Interrelationship between atrial natriuretic factor concentrations and acute volume expansion in pregnant and nonpregnant women

The secretion of atrial natriuretic factor by human atrial myocytes is stimulated by increased intraatrial pressure or atrial distention. To determine whether acute intravascular volume expansion affects atrial natriuretic factor concentrations during pregnancy, circulating atrial natriuretic factor levels were measured in pregnant women at term (before elective cesarean section) and nonpregnant control subjects before and during intravenous infusion of lactated Ringers solution (approximately 30 ml/kg). Venous plasma concentrations of alpha-human atrial natriuretic factor were determined by a specific radioimmunoassay. A significant increase in alpha-human atrial natriuretic factor levels in nonpregnant subjects was seen. Pregnant women did not show a significant response to a similar stimulus. Finally, basal alpha-human atrial natriuretic factor levels in pregnant and nonpregnant women were not different. Volume expansion (long-term or short-term) in normal human pregnancy may not be sensed by atrial volume sensors, possibly because it is accommodated by an enlarged maternal vascular compartment.