Gary R. Thurnau

Low-Dose Aspirin to Prevent Preeclampsia in Women at High Risk

Background Whether low-dose aspirin prevents preeclampsia is unclear. It is not recommended as prophylaxis in women at low risk for preeclampsia but may reduce the incidence of the disease in women at high risk. Methods We conducted a double-blind, randomized, placebo-controlled trial in four groups of pregnant women at high risk for preeclampsia, including 471 women with pregestational insulin-treated diabetes mellitus, 774 women with chronic hypertension, 688 women with multifetal gestations, and 606 women who had had preeclampsia during a previous pregnancy. The women were enrolled between gestational weeks 13 and 26 and received either 60 mg of aspirin or placebo daily. Results Outcome data were obtained on all but 36 of the 2539 women who entered the study. The incidence of preeclampsia was similar in the 1254 women in the aspirin group and the 1249 women in the placebo group (aspirin, 18 percent; placebo, 20 percent; P = 0.23). The incidences in the aspirin and placebo groups for each of the four hi...

Risk factors for preeclampsia, abruptio placentae, and adverse neonatal outcomes among women with chronic hypertension

Background Women with chronic hypertension who become pregnant have an increased risk of preeclampsia and adverse neonatal outcomes. However, within this group, the risk factors for these adverse events are not known. Methods We analyzed data on outcomes for 763 women with chronic hypertension enrolled in a multicenter trial of low-dose aspirin for the prevention of preeclampsia. Preeclampsia was defined as new-onset proteinuria (urinary protein excretion, ≥300 mg per 24 hours) in the 682 women without proteinuria at base line. It was defined according to strict clinical criteria in the 81 women who had proteinuria at base line. The end points were maternal and neonatal outcomes. Results Among the 763 women, 193 (25 percent) had preeclampsia. The frequency of preeclampsia was not affected by the presence of proteinuria at base line (27 percent among women with proteinuria, vs. 25 percent among those without it), but it was greater in women who had had hypertension for at least four years (31 percent vs. 2...

Asthma during pregnancy

OBJECTIVE: To determine neonatal and maternal outcomes stratified by asthma severity during pregnancy by using the 1993 National Asthma Education Program Working Group on Asthma and Pregnancy definitions of asthma severity. The primary hypothesis was that moderate or severe asthmatics would have an increased incidence of delivery at <32 weeks of gestation compared with nonasthmatic controls. METHODS: This was a multicenter, prospective, observational cohort study conducted over 4 years at 16 university hospital centers. Asthma severity was defined according to the National Asthma Education Program Working Group on Asthma and Pregnancy classification and modified to include medication requirements. This study had 80% power to detect a 2- to 3-fold increase in delivery less than 32 weeks of gestation among the cohort with the moderate or severe asthma compared with controls. Secondary outcome measures included obstetrical and neonatal outcomes. RESULTS: The final analysis included 881 nonasthmatic controls, 873 with mild asthma, 814 with moderate, and 52 with severe asthma. There were no significant differences in the rates of preterm delivery less than 32 weeks (moderate or severe 3.0%, mild 3.4%, controls 3.3%; P = .873) or less than 37 weeks of gestation. There were no significant differences for neonatal outcomes except discharge diagnosis of neonatal sepsis among the mild group compared with controls, adjusted odds ratio 2.9, 95% confidence interval 1.2, 6.8. There were no significant differences for maternal complications except for an increase in overall cesarean delivery rate among the moderate-or-severe group compared with controls (adjusted odds ratio 1.4, 95% confidence interval 1.1, 1.8). CONCLUSION: Asthma was not associated with a significant increase in preterm delivery or other adverse perinatal outcomes other than a discharge diagnosis of neonatal sepsis. Cesarean delivery rate was increased among the cohort with moderate or severe asthma. LEVEL OF EVIDENCE: II-2

Risk Factors and Outcome of Varicella-Zoster Virus Pneumonia in Pregnant Women

To determine the factors associated with an increased risk of developing varicella-zoster virus (VZV) pneumonia during pregnancy, a case-control analysis was done in which 18 pregnant women with VZV pneumonia were compared with 72 matched control subjects. VZV infection was identified clinically, and VZV pneumonia was diagnosed by dyspnea and findings on chest radiographs. Of 347 pregnant women with VZV infection, 18 (5.2%) had pneumonia treated with acyclovir, and none died. Mean gestational age at rash onset was 25.8 plus minus 8.8 weeks for patients with pneumonia and 17.7 +/- 10.3 weeks for control subjects, which was not significant in the multivariable model. Women with VZV pneumonia were significantly more likely to be current smokers (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.6-16.7) and to have > or = 100 skin lesions (OR, 15.9; 95% CI, 1.9-130.2). Pregnant women with VZV infection may be more likely to develop varicella pneumonia if they are smokers or manifest > or = 100 skin lesions.

Predictors of pre-eclampsia in women at high risk

OBJECTIVE We assessed several variables as predictors for pre-eclampsia risk in a group of women at high risk. STUDY DESIGN We studied 2503 women with either diabetes mellitus, chronic hypertension, multifetal gestation, or pre-eclampsia in a previous pregnancy who participated in a multicenter study comparing aspirin and placebo in preventing pre-eclampsia. We evaluated multiple variables for predicting pre-eclampsia risk with use of univariate and multivariable analysis. RESULTS Parity and mean arterial pressure at randomization were most predictive of pre-eclampsia risk. The risk was 8% with a mean arterial pressure at enrollment of <75 mm Hg versus 27% with a mean arterial pressure >85 mm Hg (relative risk and 95% confidence interval 3.3 [2.4 to 4.4]). The risk of pre-eclampsia was 26% in nulliparous patients versus 17% in parous subjects (relative risk and 95% confidence interval 1.5 [1.3-1.8]). CONCLUSIONS The finding that second-trimester mean arterial pressure affects pre-eclampsia risk suggests that the pathophysiologic process of preeclampsia is initiated before that time.

Cerebrospinal fluid levels of magnesium in patients with preeclampsia after treatment with intravenous magnesium sulfate: A preliminary report

The purpose of this study is twofold: (1) to correlate magnesium levels of serum with those of cerebrospinal fluid in patients with preeclampsia receiving intravenous magnesium sulfate, and (2) to determine whether the magnesium ion crosses the blood-brain barrier in significant amounts after intravenous magnesium sulfate therapy. Of the 21 patients in whom spinal anesthesia was used for delivery, ten patients with preeclampsia with therapeutic serum magnesium levels made up the study group and 11 term nontreated normotensive gravid women served as controls. At the time of spinal anesthesia, a 1 ml aliquot of cerebrospinal fluid was obtained from each patient. The mean cerebrospinal fluid magnesium level for the control group was 2.56 ± 0.19 mg/dl (range 2.2 to 2.8 mg/dl). For the preeclamptic group who received intravenous magnesium sulfate, the mean cerebrospinal fluid magnesium level was 3.04 ± 0.12 mg/dl (range 2.9 to 3.2 mg/dl). Although only a small amount of magnesium crosses the blood-brain barrier after intravenous magnesium sulfate treatment, this increment is highly significant (p

The Preterm Prediction Study: Association of cesarean delivery with increases in maternal weight and body mass index

OBJECTIVE Our purpose was to evaluate whether maternal weight and body mass index measured either before or during pregnancy are associated with an increased risk of cesarean delivery. STUDY DESIGN Maternal weight and height were prospectively collected on 2929 women in the National Institutes of Health Maternal-Fetal Medicine Units Network Preterm Prediction Study. Prepregnancy and 27- to 31-week maternal weight and height were used to calculate the body mass index, and its contribution to the risk of cesarean delivery was determined. Women with prenatally diagnosed congenital anomalies (n = 89) and pregestational diabetes (n = 31) were excluded from analysis. RESULTS Univariate analysis of risk factors for cesarean delivery in the 2809 eligible women revealed a decreased risk of cesarean delivery with maternal age < 18 years and multiparity; increased risk of cesarean delivery was noted with maternal age > 35 years and a male fetus. Increases in either prepregnancy or 27- to 31-week maternal weight (5-pound units) or body mass index (1.0 kg/m2 units) were significantly associated with an increased odds of cesarean delivery (p = 0.0001). Each unit increase in prepregnancy or 27- to 31-week body mass index resulted in a parallel increase in the odds of cesarean delivery of 7.0% and 7.8%, respectively. Multivariable stepwise logistic regression analysis confirmed the association of male fetus, age, nulliparity, and body mass index as significant variables contributing to cesarean delivery risk. CONCLUSIONS The risk of cesarean delivery is associated with incremental changes in maternal weight and body mass index before and during pregnancy after adjustment for potential confounding factors. Prepregnancy counseling about optimizing maternal weight and monitoring weight gain during pregnancy to decrease the risk of cesarean delivery are supported by this study.

A simple estimated fetal weight equation based on real-time ultrasound measurements of fetuses less than thirty-four weeks' gestation

Based on ultrasonographic mensuration, a number of equations have previously been devised for the purpose of estimating fetal weights. The objective of this study was to develop a mathematical equation that is simple, accurate, and easy to use when applied to preterm or low-birth weight fetuses (less than 2,500 gm). Real-time ultrasound measurements of fetal biparietal diameters (BPDs) and abdominal circumferences (ACs) were obtained in 62 pregnant women within one week of premature delivery. Mean gestational age and mean birth weight +/- SD for this study group of neonates were 28.5 +/- 3.5 weeks and 1,135 +/- 343 gm, respectively. With the aid of computer analysis, a simple regression equation was derived: EFW = (BPD x AC x 9.337) - 229. When predicted estimated fetal weight (EFW) was compared with actual birth weight (ABW), multiple regression analysis demonstrated a correlation coefficient (R) of 0.957. Preliminary results on 19 patients of a prospective study showed an absolute mean difference between the computed EFWs and the ABWs to be within 7.0% of ABW (70 gm/kg of ABW). The standard deviation of the difference was 9.3% of ABW (93 gm/kg of ABW). Based on these data, this simple equation appears to be clinically reliable and easy to use when estimating weights of preterm or low-birth weight fetuses of less than 2,500 gm.

The fetal-pelvic index as an indicator of fetal-pelvic disproportion: A preliminary report

The objective of this study was to develop a standardized method of identifying fetal-pelvic disproportion by comparing fetal head and abdomen circumferences with the respective maternal pelvic inlet and midpelvis circumferences. Fetal ultrasound and maternal x-ray pelvimetry measurements were performed on 75 term pregnant women with indications for a trial of labor. By means of individually measured fetal and maternal pelvic diameters, circumferences of the fetal head, fetal abdomen, maternal pelvic inlet, and maternal midpelvis were computed. Based on four circumference differences between the fetus and maternal pelvis (fetal head--maternal pelvic inlet, fetal head--maternal midpelvis, fetal abdomen--maternal pelvic inlet, and fetal abdomen--maternal midpelvis), a fetal pelvic index number was derived from the sum of the two most positive values. Of the 27 patients requiring cesarean sections for failure to progress in labor, all but four had positive fetal pelvic index values (sensitivity = 85%). Of the 48 patients who were delivered vaginally, all but four had negative fetal pelvic index values (specificity = 92%).

Iron Deficiency Anemia in Pregnancy

Iron deficiency is seen commonly in women during their reproductive years and particularly during pregnancy. The physician who primarily cares for women should be aware of this and initiate iron supplementation when indicated. The association of poor pregnancy outcome is of concern when iron deficiency is present in the first trimester. It is unclear whether this is because of the anemia or other epidemiologic factors. It is also unknown whether correcting iron deficiency before conception improved neo-natal outcome. Until more is known concerning IDA, it is recommended that pregnant women receive nutritional assessment and prenatal care along with adequate iron supplementation to potentially decrease the risk of poor pregnancy outcome.