Maternal thromboxane and prostacyclin levels in relation to fetal birth weight.

OBJECTIVE: To analyse whether pregnancies resulting in a small for gestational age neonate are preceded by a prostacyclin deficiency or an imbalance between thromboxane and prostacyclin. STUDY DESIGN: At five fixed time points during pregnancy, 24-h urine samples were collected for the measurement of thromboxane and prostacyclin metabolites thromboxane-B(2) (TXB(2)) and 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)). In order to study trend differences between pregnancies with appropriate (AGA; n=26) and small for gestational age neonates (SGA; n=17), trend analysis with simple contrasts were accomplished for TXB(2), 6-keto-PGF(1alpha) and the TXB(2)/6-keto-PGF(1alpha) ratio. RESULTS: Trend analysis showed higher TXB(2) levels and higher TXB(2)/6-keto-PGF(1alpha) ratios in patients with SGA versus AGA newborns. No statistically significant difference in 6-keto-PGF(1alpha) excretion between patients with SGA and AGA newborns was detected. CONCLUSION: The birth of an SGA neonate is not preceded by prostacyclin deficiency. With ongoing pregnancy an imbalance between thromboxane and prostacyclin becomes more obvious in pregnancies with SGA newborns.

Psychosocial predictors of low birthweight: a prospective study.

OBJECTIVE: To examine the role of psychosocial risk factors for low birthweight. DESIGN: A prospective study. SETTING: Obstetric outpatient clinics of the University Hospital Vrije Universiteit, Amsterdam. PARTICIPANTS: Three hundred and ninety-six nulliparous women. METHODS: Questionnaires on background variables, daily stressors, psychological and mental wellbeing, social support and work factors were completed by the women in the first, second and third trimester of pregnancy. Low birthweight for gestational age was defined at different cut off points: 1. < or = 10th customised birthweight centile (n = 69); 2. < or = 5th customised birthweight centile (n = 54); 3. < 3rd customised birthweight centile (n = 35); and 4. < or = the 10th Dutch birthweight centile (n = 40). Multivariate logistic regression was applied and the results were expressed in odds ratios and their 95% confidence intervals. RESULTS: When the cut off level was defined < or = 5th and < 3rd customised centile, the number of daily stressors in the first trimester was a statistically significant risk factor (OR 1.04, 95% CI 1.01-1.07 and OR 1.04, 95% CI 1.01-1.08). No significant psychosocial risk factors could be identified when low birthweight for gestational age was defined < or = the 10th customised birthweight centile. When low birthweight for gestational age was defined < or = the 10th Dutch birthweight centile, number of hours housekeeping per week in the first trimester (OR 1.59, 95% CI 1.03-2.46), low subjective severity rating of daily stressors in the first trimester (OR 0.41, 95% CI 0.17-0.97) and depressive mood in the first trimester (OR 1.12, 95% CI 1.01-1.24) were statistically significant psychosocial risk factors after controlling for maternal weight and height, number of cigarettes smoked per day and educational level. CONCLUSIONS: In the first trimester of pregnancy maternal psychosocial factors are associated with an increased risk of low birthweight. The specific psychosocial risk factors found were different when the definition of low birthweight was changed. Therefore, in this field of research, we suggest use of the most valid outcome measure for low birthweight, being the customised birthweight centiles.

Vasoactive mediators in pregnancy-induced hypertensive disorders: a longitudinal study.

OBJECTIVE: The objective of this study was to evaluate the extent to which endothelin and the eicosanoids prostacyclin and thromboxane A2 are involved in the pathophysiology of gestational hypertension and preeclampsia. STUDY DESIGN: In a longitudinal design, venous blood samples and 24-hour urine specimens were collected from 396 women in each trimester of pregnancy. After delivery of all patients, venous plasma endothelin was assessed in 20 subjects with identified preeclampsia, 48 subjects with gestational hypertension, and 59 normotensive subjects. Urinary excretions of the thromboxane A2 and of the prostacyclin metabolites thromboxane B2 and 6-keto-prostaglandin F1 alpha were assessed in 16 subjects with preeclampsia, 35 subjects with gestational hypertension, and 31 normotensive subjects. RESULTS: Endothelin levels showed a second-trimester drop in all groups. In all 3 gestational trimesters a high correlation was found between the excretion of thromboxane B2 and that of 6-keto-prostaglandin F1 alpha (P <.001). The overall thromboxane B2 and 6-keto-prostaglandin F1 alpha urinary excretions increased throughout pregnancy and the overall thromboxane B2 /6-keto-prostaglandin F1 alpha ratio decreased. No significant differences in endothelin, thromboxane B2, and 6-keto-prostaglandin F1 alpha excretion levels or in thromboxane B2 /6-keto-prostaglandin F1 alpha ratios were found between women with preeclampsia, gestational hypertension, and normotension. Only in a small group of patients with severe preeclampsia (n = 2) and severe gestational hypertension (n = 2) were increased second-trimester endothelin values and increased thromboxane B2 /6-keto-prostaglandin F1 alpha ratios found. CONCLUSION: In this longitudinal study we found no evidence for prostacyclin deficiency or increased endothelin levels in preeclampsia. Only women with severe preeclampsia and severe gestational hypertension expressed increased endothelin levels and thromboxane dominance over prostacyclin.

Total plasma fibronectin as a marker of pregnancy-induced hypertensive disorders: a longitudinal study.

OBJECTIVE: To determine normal values of total plasma fibronectin in all three gestational trimesters and to examine 1) whether total plasma fibronectin levels differ between normotensive, hypertensive, and preeclamptic women; and 2) whether total plasma fibronectin may serve as an early marker of pregnancy-induced hypertensive disorders. METHODS: Total plasma fibronectin was measured in 376 nulliparous women once in each trimester of pregnancy. Normotensive controls (n = 222) and subjects with pregnancy-induced hypertensive disorders (n = 154) were identified after delivery. The group with pregnancy-induced hypertensive disorders was subdivided into a gestational hypertensive group (n = 125) and a preeclamptic group (n = 29). A complete total plasma fibronectin data set was obtained from 347 subjects. Trends in total plasma fibronectin values were compared for the different groups and relative risks (RRs) were calculated after optimal cutoff levels had been determined by receiver operating characteristic curves. RESULTS: Total plasma fibronectin values (+/- standard error of the mean) were 227 +/- 3 mg/L in the first, 219 +/- 3 mg/L in the second, and 260 +/- 5 mg/L in the third trimesters in normotensive pregnancies. In the first trimester and persisting throughout pregnancy, total plasma fibronectin levels were significantly higher in patients with pregnancy-induced hypertensive disorders than in controls and showed a sharper increase throughout pregnancy. Increased first-trimester total plasma fibronectin levels result in an RR of 1.4 (95% confidence interval [CI] 1.1, 1.8) of developing a pregnancy-induced hypertensive disorder in general. The RR for the development of preeclampsia was 1.7 (95% CI 0.9, 3.4), which was not significant, when the first-trimester total plasma fibronectin level was above the cutoff level of 240 mg/L. The RR for developing preeclampsia was 3.8 (95% CI 1.8, 8.0) when the second-trimester total plasma fibronectin level increased above 230 mg/L. CONCLUSION: The findings of the present study confirm those of previous studies that have found increased total plasma fibronectin levels in pregnancy-induced hypertensive disorders. This study discovered that in these women, total plasma fibronectin levels are elevated in the first trimester. Total plasma fibronectin appears to be a poor predictor of preeclampsia when measured in a general pregnant population. Therefore, total plasma fibronectin should not be used as a routine screening test in a low-risk population. However, obstetricians may use total plasma fibronectin values to help determine the relative risk of developing pregnancy-induced hypertensive disorders.

Decreased first trimester uric acid production in future preeclamptic patients.

The relationship between first trimester uric acid production and later development of pregnancy induced hypertensive disorders (PIHD) was investigated. An anti-oxidant role for uric acid has been mentioned. Since uric acid and fibronectin (PF) are both markers of preeclampsia, the relationship between these two substances was also studied. Controls (n = 72) and patients with PIHD (n = 120) were selected. Uric acid was measured in serum and 24-hours urine samples (uric acid excretion) and PF in blood plasma in 270 nulliparous women at 13 +/- 2 weeks of gestation. Uric acid excretion was significantly lower in the first trimester in a group of patients who later develop PIHD as compared to patients who remain normotensive (p < 0.05), especially when corrected for body weight (p < 0.01). Patients with elevated PF levels in the first trimester showed a significantly lower uric acid excretion than patients with normal PF levels (p < 0.05). The data show diminished uric acid production in patients who will likely develop preeclampsia suggesting an impaired anti-oxidant production in the first trimester. This observation fits well with the hypothesis that an imbalance between anti-oxidant and oxidants plays an important role in the pathogenesis of preeclampsia.

Psychosocial factors as predictors of maternal well-being and pregnancy-related complaints.

The aim of the current study was to investigate the effects of psychosocial variables on well-being and on pregnancy-related complaints throughout pregnancy. Three hundred and ninety-six nulliparous women completed questionnaires on number of daily stressors, social support, gestational factors and mental and physical work load in each trimester of pregnancy. In addition, the following dependent measures were assessed: depression, anxiety, somatic complaints, and the pregnancy-related complaints fatigue, nausea and back pain. The independent variables predicted depression best (r2 = 42-44%), followed by anxiety (R2 = 13-20) and somatic complaints (R2 = 16-21%). Number of daily stressors explained most of the variance. Satisfaction with social support and maternal age were negatively correlated with depression. In contrast, pregnancy-related complaints could be less accurately predicted by psychosocial factors. The amount of explained variance for fatigue ranged between 6 and 10%, for nausea between 2 and 6%, and for back pain between 5 and 7% for the three trimesters. It is concluded that depressive symptoms during pregnancy are associated with negative psychosocial factors, particularly the number of daily stressors and low satisfaction with received social support. To a lesser degree, this is also the case with anxiety and somatic complaints. Pregnancy-related complaints, on the other hand, appear to be relatively independent of psychosocial conditions.

Psychosocial factors and pregnancy outcome: a review with emphasis on methodological issues.

This review focuses on the research concerning the relation between psychosocial factors and pregnancy outcome. The following four outcome measures are dealt with: (1) birth weight, (2) preeclampsia, (3) preterm labour, and (4) intrapartum complications. The most consistent finding concerns the association between maternal exposure to taxing situations and preterm delivery. Three possible pathways are hypothesized: (1) an indirect influence via unhealthy coping and life style behaviour, (2) a direct influence via stress-dependent hormones, and (3) an additional direct influence via psycho-immunological factors. Intervention studies aimed at improving pregnancy outcome show fairly mixed results. It is recommended that studies on the relationship between psychosocial factors and pregnancy outcome should employ a prospective design with due attention to chronic stressors, should include appropriate biochemical assessments, and multivariate techniques are applied.