High-risk Singleton Pregnancies Research Articles

Influence of maternal nutritional status, weight gain and energy intake on fetal growth in high-risk pregnancies

To analyze the influence of maternal nutritional status, weight gain and energy consumption on fetal growth in high-risk pregnancies. A prospective study from August 2009 to August 2010 with the following inclusion criteria: puerperae up to the 5th postpartum day; high-risk singleton pregnancies (characterized by medical or obstetrical complications during pregnancy); live fetus at labor onset; delivery at the institution; maternal weight measured on the day of delivery, and presence of medical and/or obstetrical complications characterizing pregnancy as high-risk. Nutritional status was assessed by pregestational body mass index and body mass index in late pregnancy, and the patients were classified as: underweight, adequate, overweight and obese. A food frequency questionnaire was applied to evaluate energy consumption. We investigated maternal weight gain, delivery data and perinatal outcomes, as well as fetal growth based on the occurrence of small for gestational age and large for gestational age neonates. We included 374 women who were divided into three study groups according to newborn birth weight: adequate for gestational age (270 cases, 72.2%), small for gestational age (91 cases, 24.3%), and large for gestational age (13 cases, 3.5%). Univaried analysis showed that women with small for gestational age neonates had a significantly lower mean pregestational body mass index (23.5 kg/m², p<0.001), mean index during late pregnancy (27.7 kg/m², p<0.001), and a higher proportion of maternal underweight at the end of pregnancy (25.3%, p<0.001). Women with large for gestational age neonates had a significantly higher mean pregestational body mass index (29.1 kg/m², p<0.001), mean index during late pregnancy (34.3 kg/m², p<0.001), and a higher proportion of overweight (30.8%, p=0.02) and obesity (38.5%, p=0.02) according to pregestational body mass index, and obesity at the end of pregnancy (53.8%, p<0.001). Multivariate analysis revealed the index value during late pregnancy (OR=0.9; CI95% 0.8-0.9, p<0.001) and the presence of hypertension (OR=2.6; 95%CI 1.5-4.5, p<0.001) as independent factors for small for gestational age. Independent predictors of large for gestational age infant were the presence of diabetes mellitus (OR=20.2; 95%CI 5.3-76.8, p<0.001) and obesity according to body mass index during late pregnancy (OR=3.6; 95%CI 1.1-11.7, p=0.04). The maternal nutritional status at the end of pregnancy in high-risk pregnancies is independently associated with fetal growth, the body mass index during late pregnancy is a protective factor against small for gestational age neonates, and maternal obesity is a risk factor for large for gestational age neonates.

Transvaginal Sonographic Evaluation of the Cervix in Asymptomatic Singleton Pregnancy and Management Options in Short Cervix

Preterm delivery (PTD), defined as birth before 37 completed weeks of gestation, is the leading cause of perinatal morbidity and mortality. Evaluation of the cervical morphology and biometry with transvaginal ultrasonography at 16–24 weeks of gestation is a useful tool to predict the risk of preterm birth in low- and high-risk singleton pregnancies. For instance, a sonographic cervical length (CL) > 30 mm and present cervical gland area have a 96-97% negative predictive value for preterm delivery at <37 weeks. Available evidence supports the use of progesterone to women with cervical length ≤25 mm, irrespective of other risk factors. In women with prior spontaneous PTD with asymptomatic cervical shortening (CL ≤ 25 mm), prophylactic cerclage procedure must be performed and weekly to every two weeks follow-up is essential. This article reviews the evidence in support of the clinical introduction of transvaginal sonography for both the prediction and management of spontaneous preterm labour.

Intrapartum epidural analgesia and ST analysis of the fetal electrocardiogram

To evaluate the influence of intrapartum epidural analgesia on the occurrence of ST events of the fetal ECG. Nested case-control study. Single-centre academic hospital in the Netherlands. Laboring women with a high-risk singleton pregnancy in cephalic position beyond 36 weeks of gestation. Data of 72 women who received epidural analgesia using bupivacaine combined with sufentanil and 72 control women were collected and analyzed. The moment of epidural infusion was defined as t(0) . In the control group, t(0) was defined by matching dilatation in centimeters. STAN registrations from one hour before until two hours after t(0) were classified, and the numbers and types of ST events were recorded and judged according to the STAN clinical guidelines. T/QRS ratios were collected from one hour before t(0) until two hours after t(0) , and differences were compared between the two groups. Numbers and types of ST events and mean T/QRS ratios before and after t(0). There were no significant differences between cases and control women regarding the numbers of ST events, types of ST events and whether they were significant (intervention advised) or not. Correction for outliers (three cases and three control women) did not change the results. Differences of T/QRS ratios before and after t(0) were comparable between cases and control women. Epidural analgesia has no effect on the numbers or types of ST events when using ST analysis of the fetal ECG.

Vaginal micronized progesterone and risk of preterm delivery in high‐risk twin pregnancies: secondary analysis of a placebo‐controlled randomized trial and meta‐analysis

Progesterone treatment reduces the risk of preterm delivery in high-risk singleton pregnancies. Our aim was to evaluate the preventive effect of vaginal progesterone in high-risk twins. This was a subanalysis of a Danish-Austrian, double-blind, placebo-controlled, randomized trial (PREDICT study), in which women with twin pregnancies were randomized to daily treatment with progesterone or placebo pessaries from 20-24 weeks until 34 weeks' gestation. This subpopulation consisted of high-risk pregnancies, defined by the finding of cervical length ≤ 10th centile at 20-24 weeks' gestation or history of either spontaneous delivery before 34 weeks or miscarriage after 12 weeks. Primary outcome was delivery before 34 weeks. Secondary outcomes were complications for infants including long-term follow-up by Ages and Stages Questionnaire (ASQ) at 6 and 18 months of age. In 72 (10.6%) of the 677 women participating in the PREDICT study, the pregnancy was considered to be high-risk, including 47 with cervical length ≤ 10th centile, 28 with a history of preterm delivery or late miscarriage and three fulfilling both criteria. Baseline characteristics for progesterone and placebo groups were similar. Mean gestational age at delivery did not differ significantly between the two groups either in patients with a short cervix (34.3 ± 4.1 vs. 34.5 ± 3.0 weeks, P = 0.87) or in those with a history of preterm delivery or late miscarriage (34.6 ± 4.2 vs. 35.2 ± 2.7 weeks, P = 0.62). Similarly, there were no significant differences between the treatment groups in maternal or neonatal complications and mean ASQ score at 6 and 18 months of age. In high-risk twin pregnancies, progesterone treatment does not significantly improve outcome.

Prediction of Neonatal Metabolic Acidosis in Women with a Singleton Term Pregnancy in Cephalic Presentation

We sought to predict neonatal metabolic acidosis at birth using antepartum obstetric characteristics (model 1) and additional characteristics available during labor (model 2). In 5667 laboring women from a multicenter randomized trial that had a high-risk singleton pregnancy in cephalic presentation beyond 36 weeks of gestation, we predicted neonatal metabolic acidosis. Based on literature and clinical reasoning, we selected both antepartum characteristics and characteristics that became available during labor. After univariable analyses, the predictors of the multivariable models were identified by backward stepwise selection in a logistic regression analysis. Model performance was assessed by discrimination and calibration. To correct for potential overfitting, we (internally) validated the models with bootstrapping techniques. Of 5667 neonates born alive, 107 (1.9%) had metabolic acidosis. Antepartum predictors of metabolic acidosis were gestational age, nulliparity, previous cesarean delivery, and maternal diabetes. Additional intrapartum predictors were spontaneous onset of labor and meconium-stained amniotic fluid. Calibration and discrimination were acceptable for both models (c-statistic 0.64 and 0.66, respectively). In women with a high-risk singleton term pregnancy in cephalic presentation, we identified antepartum and intrapartum factors that predict neonatal metabolic acidosis at birth.

O6. Uterine artery Doppler in a risk population: What’s its role in the prediction of small for gestational age fetuses?

Objective: The aim of this retrospective study was to assess the role of uterine artery (UtA) Doppler velocimetry in the prediction of small for gestational age (SGA) fetuses in a high risk population. Methods: A population of 145 singleton high risk pregnancies was evaluated with serial UtA Doppler performed within 23 weeks (I UtADoppler) and between 23 and 30 weeks’ gestation (II UtA Doppler). Risk population was composed by women with chronic hypertension or with a previous pregnancy complicated by one of the following: preeclampsia, stillbirth, abruptio placentae, small for gestational age newborns. The association between an abnormal UtA velocimetry (Resistance Index > 0.58 and/or bilateral notch) and the probability to develop SGA fetuses was analysed. SGA fetuses were diagnosed on the base of ultrasonographic measurement of abdominal circumference below the 10 centile. Therapy with low-dose aspirin and/or Low Weight Molecular Heparin was prescribed according with a clinical protocol. Results: Gestational age at delivery, mean birth weight, abnormal UtA Doppler and Umbilical artery Doppler were significantly different between SGA fetuses and not SGA fetuses (Table 1). Particularly 30% of SGA fetuses with an abnormal UtA Doppler had also an abnormal Umbilical artery Doppler (defined as a Pulsatility Index >95 centile). Logistic regression analysis showed that only the abnormal UtA Doppler test performed between 23 and 30 weeks’ gestation independently correlated with SGA fetuses, otherwise ASA was a significant protective factor for SGA fetuses (Table 2). Persistence of abnormal UtA Doppler was associated with a statistically higher rate of SGA. Conclusion: An abnormal UtA Doppler in the late second or early third trimester remained the variable significantly related with SGA fetuses; therefore UtA Doppler evaluation between 23 and 30 weeks could be useful for the management of high risk population. ASA was a significant protective factor for intrauterine growth.

Fetal blood sampling in addition to intrapartum ST-analysis of the fetal electrocardiogram: evaluation of the recommendations in the Dutch STAN® trial

To evaluate the recommendations for additional fetal blood sampling (FBS) when using ST-analysis of the fetal electrocardiogram. Prospective cohort study. Three academic and six non-academic teaching hospitals in the Netherlands. Labouring women with a high-risk singleton pregnancy in cephalic position beyond 36 weeks of gestation. In labouring women allocated to the STAN® arm of a previously published randomised controlled trial who underwent one or more FBS during delivery, we assessed whether FBS was performed according to the trial protocol and how fetal acidosis, defined as an FBS pH < 7.20, was related to ST-waveform analysis. The number of FBS showing fetal acidosis, related to the different STAN® criteria where additional FBS is recommended. Among 2827 women monitored with STAN®, 297 underwent FBS, of whom 171 (57.6%) were performed according to the predefined criteria and 126 were performed in absence of these criteria. In the first group, rates of fetal acidosis (pH < 7.20) were two of 18, none of nine, 12 of 111 and three of 33 when FBS was taken for abnormal cardiotocogram (CTG) at the start, intermediary CTG at the start, abnormal CTG >60 minutes, and poor electrocardiogram quality, respectively. When the predefined criteria were not met and ST-analysis showed no ST-events, only two incidents of fetal acidosis were seen. The performance of FBS is valuable in the advised STAN® criteria. When these criteria are not met, performance of FBS does not seem helpful in the detection of fetal acidosis.

Effect of maternal betamethasone on fetal and uteroplacental blood flow velocity waveforms

To investigate the effects of antenatal betamethasone on fetal and uteroplacental hemodynamics. The study comprised 33 women with singleton high-risk pregnancies (23-33 weeks; 27 pregnancies < 30 weeks) not in labor, but at risk for preterm delivery based on fetal or maternal indications. They were treated with two doses of 12 mg betamethasone intramuscularly 24 h apart to enhance fetal lung maturity. Flow velocity waveforms were recorded with Doppler ultrasound from the umbilical artery, the fetal middle cerebral artery, the ductus venosus and both maternal uterine arteries, once before and twice after betamethasone administration. Twenty-one (64%) women delivered within 4 days, nine (27%) women within 5-7 days and three (9%) within 8-15 days after the first dose of betamethasone. Two days after betamethasone, a decrease in pulsatility index was found in the umbilical artery (P = 0.0002) and ductus venosus (P = 0.003). Changes in the umbilical artery waveform from reversed to absent, and from absent to positive diastolic flow, were noted in 12 of 15 cases (P < 0.01). After 4 days, umbilical artery and ductus venosus velocity waveforms in the undelivered fetuses either returned to the type of waveform observed before treatment or showed further deterioration. No significant effects of betamethasone were observed in the fetal middle cerebral artery and uteroplacental circulation. Maternal antenatal betamethasone resulted in a significant transient change in the velocity waveform and a decrease in the pulsatility index in the umbilical artery and ductus venosus, but did not influence uteroplacental circulation. These findings indicate a direct effect of betamethasone on fetal circulation.

Placental Infarction and Thrombophilia

To estimate the relative importance of positive maternal thrombophilia testing compared with additional pathological evidence of abnormal placentation with placental infarction. We performed a retrospective cohort study over a 10-year period in 180 singleton high-risk pregnancies (delivery at 22-34 6/7 weeks of gestation) that had histologic evidence of placental infarction. The rate of positive maternal tests for antiphospholipid syndrome, factor V Leiden, and prothrombin gene mutation were compared with the rate of detection of one or more gross or histological features of abnormal placentation (impaired placental development or differentiation, maternal vascular underperfusion, fetal vascular underperfusion, chronic inflammation, or intervillous thrombosis). Only 14 of 108 (13.0%) of placentas with documented infarction were associated with a positive maternal thrombophilia result. In contrast, 67 of 108 (62.3%) placentas showed features of abnormal placental development or differentiation and 85 of 108 (78.7%) had evidence of noninfarct-related maternal vascular underperfusion (P<.001). Only four of 108 (3.7%) infarcted placentas had no other pathologic lesions. Our data indicate that gross and histologic features of abnormal placentation associate strongly with placental infarction in comparison with maternal thrombophilia tests. II.

Cochrane Reviews' summaries and their relevance for imaging: Doppler in obstetrics

Cochrane Reviews' summaries and their relevance for imaging: Doppler in obstetrics

Soluble Endoglin for the Prediction of Preeclampsia in a High Risk Cohort

Objectives. To evaluate soluble endoglin (sEng) and the soluble fms-like tyrosine kinase 1 (sFlt1) to placental growth factor (PlGF) ratio for the prediction of preeclampsia in high-risk women, and to evaluate differences in sEng between women with high-risk singleton and multiple gestation pregnancies. Study Design. We collected serial serum specimens from 119 women at high preeclampsia risk. sEng, sFlt1 and PlGF were measured by ELISA. Results. Among subjects who did not develop preeclampsia, mean serum sEng was significantly higher in those with multiple gestation pregnancies vs. high-risk singletons. Among women with singleton gestations, mean serum sEng was higher in subjects who developed early-onset (<34 weeks) and late-onset (≥ 34 weeks) preeclampsia, as compared with subjects without preeclampsia, from 22 weeks and 28 weeks gestation onward, respectively. The within-woman rate of change of sEng was also higher in women who later developed preeclampsia. Conclusions. sEng is higher in women with multiple gestations vs. high-risk singleton pregnancies. In high-risk women, serum sEng is increased prior to preeclampsia onset.

Cardiotocography Plus ST Analysis of Fetal Electrocardiogram Compared With Cardiotocography Only for Intrapartum Monitoring

To estimate the effectiveness of intrapartum fetal monitoring by cardiotocography plus ST analysis using a strict protocol for performance of fetal blood sampling. We performed a multicenter randomized trial among laboring women with a high-risk singleton pregnancy in cephalic presentation beyond 36 weeks of gestation. Participants were assigned to monitoring by cardiotocography with ST analysis (index) or cardiotocography only (control). Primary outcome was metabolic acidosis, defined as an umbilical cord artery pH below 7.05 combined with a base deficit calculated in the extracellular fluid compartment above 12 mmol/L. Secondary outcomes were metabolic acidosis in blood, operative deliveries, Apgar scores, neonatal admissions, and hypoxic-ischemic encephalopathy. We randomly assigned 5,681 women to the two groups (2,832 index, 2,849 control). The fetal blood sampling rate was 10.6% in the index compared with 20.4% in the control group (relative risk 0.52; 95% [CI] 0.46-0.59). The primary outcome occurred 0.7% in the index compared with 1.1% in the control group (relative risk 0.70; 95% CI 0.38-1.28; number needed to treat 252). Using metabolic acidosis calculated in blood, these rates were 1.6% and 2.6%, respectively (relative risk 0.63; 95% CI 0.42-0.94; number needed to treat 100). The number of operative deliveries, low Apgar scores, neonatal admissions, and newborns with hypoxic-ischemic encephalopathy was comparable in both groups. Intrapartum monitoring by cardiotocography combined with ST analysis does not significantly reduce the incidence of metabolic acidosis calculated in the extracellular fluid compartment. It does reduce the incidence of metabolic acidosis calculated in blood and the need for fetal blood sampling without affecting the Apgar score, neonatal admissions, hypoxic-ischemic encephalopathy, or operative deliveries. I.

Uterine venous blood flow in normal and complicated pregnancies: a methodological study

To investigate the possibility of recording Doppler flow signals from the maternal uterine veins (UtVs) during pregnancy and to assess the relationship between UtV signals and other Doppler parameters as well as pregnancy outcomes. Transabdominal Doppler ultrasound examination of the UtVs on both sides of the uterus was performed in 40 normal and 44 high-risk singleton pregnancies at 23-39 weeks' gestation. The UtV was identified using color Doppler imaging and the flow velocity signals of the UtV and uterine artery (UtA) were recorded. Morphological examination of the placenta was carried out in 45 of the pregnancies (14 uncomplicated and 31 high-risk pregnancies). Flow-velocity signals of the UtVs were recorded from at least one side of the uterus in all patients (success rate of 81 and 89% for the right and left UtV, respectively). Three types of flow-velocity pattern were identified: continuous non-pulsatile flow (Type I, n = 70), pulsatile flow with a notch touching the zero line (Type II, n = 6) and pulsatile flow with absent flow signals for part of the heart cycle (Type III, n = 8). The UtA pulsatility index was significantly higher in women with UtV Types II and III than in those with UtV Type I (P = 0.039). Similarly, UtV Types II and III were more often found in pregnancies with bilateral UtA notching (P = 0.013) and with UtA score 3-4 (P = 0.024) than in those with normal UtA. No statistically significant association was found between the UtV flow pattern and abnormal histopathological findings in the placenta, or between the UtV and umbilical artery findings. It is possible to record Doppler signals from the UtVs in the late second and third trimesters of pregnancy. Pulsatile flow-velocity patterns of the UtVs are associated with abnormal UtA Doppler findings.

Progesterone for the Prevention of Preterm Birth in Twin Pregnancy (STOPPIT): A Randomized, Double-Blind, Placebo-Controlled Study and Meta-Analysis

Women with twin pregnancy are at high risk of spontaneous preterm delivery. Three large randomized trials have shown that progesterone reduces the rate of preterm delivery in high-risk singleton pregnancies, although evidence of significant reduction in perinatal mortality or clear neonatal benefit in singleton women is lacking. The STOPPIT study was a randomized, double-blind, placebo-controlled trial designed to evaluate the potential benefit of progesterone for prevention of preterm birth in women with twin pregnancy. Between 2004 and 2008, 500 women with twin pregnancy were enrolled from 9 antenatal clinics at hospitals in the United Kingdom. At 24 weeks of gestation, the study subjects were randomized to either 90 mg of vaginal progesterone gel (n = 250) or placebo gel (n = 250) daily for 10 weeks. The primary study outcome was delivery or intrauterine death before 34 weeks of gestation. Analysis was performed according to intention to treat. The investigators also performed a meta-analysis of all published and unpublished studies in which women with twin pregnancy were randomly allocated to treatment with a progesterone (including progesterone). No significant difference was found between the 2 groups in the combined proportion of twin pregnancies that resulted in intrauterine death or delivery before 34 weeks (24.7% or 61/247 in the progesterone group vs. 19.4% or 48/247 in the placebo group; odds ratio, 1.36; 95% confidence interval, 0.89–2.09; P = 0.16). The meta-analysis, which included pooled data from 2 studies fulfilling inclusion criteria and data from the present study, confirmed that progesterone does not reduce the risk of early preterm birth or intrauterine death in twin pregnancies (pooled odds ratio, 1.16; 95% confidence interval, 0.89–1.51). No difference between the 2 groups was found in the rate of adverse events. These findings are consistent with previous studies showing that progestogens do not prevent preterm delivery in women with twin pregnancy.

Progesterone for the prevention of preterm birth in twin pregnancy (STOPPIT): a randomised, double-blind, placebo-controlled study and meta-analysis

Women with twin pregnancy are at high risk for spontaneous preterm delivery. Progesterone seems to be effective in reducing preterm birth in selected high-risk singleton pregnancies, albeit with no significant reduction in perinatal mortality and little evidence of neonatal benefit. We investigated the use of progesterone for prevention of preterm birth in twin pregnancy. In this double-blind, placebo-controlled trial, 500 women with twin pregnancy were recruited from nine UK National Health Service clinics specialising in the management of twin pregnancy. Women were randomised, by permuted blocks of randomly mixed sizes, either to daily vaginal progesterone gel 90 mg (n=250) or to placebo gel (n=250) for 10 weeks from 24 weeks' gestation. All study personnel and participants were masked to treatment assignment for the duration of the study. The primary outcome was delivery or intrauterine death before 34 weeks' gestation. Analysis was by intention to treat. Additionally we undertook a meta-analysis of published and unpublished data to establish the efficacy of progesterone in prevention of early (<34 weeks' gestation) preterm birth or intrauterine death in women with twin pregnancy. This study is registered, number ISRCTN35782581. Three participants in each group were lost to follow-up, leaving 247 analysed per group. The combined proportion of intrauterine death or delivery before 34 weeks of pregnancy was 24.7% (61/247) in the progesterone group and 19.4% (48/247) in the placebo group (odds ratio [OR] 1.36, 95% CI 0.89-2.09; p=0.16). The rate of adverse events did not differ between the two groups. The meta-analysis confirmed that progesterone does not prevent early preterm birth in women with twin pregnancy (pooled OR 1.16, 95% CI 0.89-1.51). Progesterone, administered vaginally, does not prevent preterm birth in women with twin pregnancy. Chief Scientist Office of the Scottish Government Health Directorate.

What is the contribution of Doppler sonography of the umbilical artery in diagnosis of intrauterine growth retardation?

Pulsed Dopplersonography of the umbilical artery was performed in 155 singleton high-risk pregnancies without malformations or chromosomal abnormalities. 59 foetuses were classified as foetuses with intrauterine growth retardation (IUGR). 46 of them had a birth weight below the tenth percentile. In 20 cases the pulsatility index (PI) was elevated (sensitivity: 44%). In all there were 50 neonates with a birth weight below the tenth percentile, 46 of whom were detected by biometry (sensitivity: 92%). 8 dystrophic neonates with a biometry that revealed IUGR were compromised by perinatal asphyxia. In six cases operative delivery was necessary and two cases with reversed diastolic flow ended in intrauterine foetal death. 7 of those foetuses had an elevated PI. The sensitivity of Dopplersonography in this group was 88%, the negative predictive value 97%. The positive predictive value with regard to a dystrophic neonate can be improved from 78% to 91%, if compared with biometry alone. Summing up, Dopplersonography of the umbilical artery can distinguish very well between IUGR foetuses at risk of perinatal morbidity or mortality and those IUGR foetuses with sufficient placental circulation who are, therefore, not at risk.

Circulating angiogenic factors in singleton vs multiple-gestation pregnancies

Placental soluble fms-like tyrosine kinase-1 may contribute to the pathogenesis of preeclampsia. Here we describe alterations in serum angiogenic factor levels in women with multiple gestation pregnancies, a major preeclampsia risk factor. We collected serial serum specimens from 101 pregnant women at high preeclampsia risk between 22 and 36 weeks' gestation. Soluble fms-like tyrosine kinase-1 and placental growth factor were measured by enzyme-linked immunosorbent assay. Women who had preeclampsia or gestational hypertension develop were excluded. Maternal soluble fms-like tyrosine kinase-1 was higher in multiple gestation (n = 20) compared with high-risk singleton (n = 81) pregnancies for each gestational age range examined. Maternal placental growth factor was significantly higher in multiple vs high-risk singletons before 31 weeks' gestation, whereas the soluble fms-like tyrosine kinase-1/placental growth factor ratio was higher in multiple vs high-risk singletons after 27 weeks. Alterations in circulating angiogenic factors are present in women with multiple gestations and may contribute to higher preeclampsia risk in this population.

Diurnal nonstress test variations in the human fetus at risk

Objective: To compare the results of the nonstress test (NST) performed at 9:00 PM and 9:00 AM on women with high-risk pregnancies. Method: The NST was performed 2 h after a meal, at 9:00 AM and 9:00 PM, in a quiet room exposed to daylight, on 80 women with high-risk singleton pregnancies. Each session lasted 20 min. If the NST was nonreactive, the entire biophysical profile was immediately performed. The women's blood pressure was measured before, 10 min within, and at the end of the NST. Women who smoked or had uterine contractions were excluded from the study. Results: Diurnal nonstress test variations were manifested by a higher incidence of reactive NSTs and an increased number of fetal heart accelerations after 9:00 PM (82.5%) than at 9:00 AM (68.8%) ( p < 0.027 P < 0.001). Conclusions: Evening appointments for fetal assessments, except in emergency conditions, may eliminate the need for additional tests such as the entire biophysical profile because of the decreased incidence of nonreactive NSTs. Evening NSTs would save time and decrease maternal anxiety.

Noninvasive ultrasound assessment of maternal vascular reactivity during pregnancy: a longitudinal study.

To estimate the pattern of maternal vascular reactivity in normal and high-risk pregnancies using postocclusion brachial artery diameter. Prospective, longitudinal study of 44 low-risk singleton pregnancies and 28 high-risk pregnancies, defined as pregestational diabetes (n = 7), chronic hypertension (n = 4), twin gestation (n = 6), and a previous history of preeclampsia, fetal growth restriction, or vascular disease (n = 11). During each trimester, the brachial artery was ultrasonographically imaged above the antecubital crease. Brachial artery diameter was measured and then occluded for 5 minutes using an inflated blood pressure cuff. Changes in brachial artery diameter at 1 minute after occlusion were expressed as percent change from baseline and were compared across trimesters for both low-risk and high-risk groups, adjusting for potential confounders. Brachial artery diameters were increased after occlusion in every trimester for all groups. For low-risk women, the degree of postocclusion brachial artery dilatation was similar in the first and second trimesters, but was lower in the third trimester. In the first trimester, low-risk women had significantly greater brachial artery diameter increases at 1 minute compared with high-risk singleton pregnancies (19% compared with 12%; P <.001). Compared with low-risk women, pregnancies complicated by pregestational diabetes or chronic hypertension had significantly smaller 1-minute brachial artery diameter changes in the first trimester (7.0 +/- 0.5%, P <.001), whereas twin gestations had greater brachial artery responses (22.9 +/- 6.0%, P <.001). Women with previous preeclampsia or vascular disease had responses similar to low-risk women. Maternal vascular reactivity as assessed by postocclusion brachial artery dilatation decreases in the third trimester in both low-risk and high-risk women. In addition, singleton pregnancies at high risk for preeclampsia display decreased brachial artery reactivity compared with low-risk women.

Prophylactic administration of progesterone by vaginal suppository to reduce the incidence of spontaneous preterm birth in women at increased risk: A randomized placebo-controlled double-blind study

Objective: The purpose of this study was to evaluate the effect of prophylactic vaginal progesterone in decreasing preterm birth rate in a high-risk population. Study design: A randomized, double-blind, placebo-controlled study included 142 high-risk singleton pregnancies. Progesterone (100 mg) or placebo was administered daily by vaginal suppository and all patients underwent uterine contraction monitoring with an external tocodynamometer once a week for 60 minutes, between 24 and 34 weeks of gestation. Progesterone (n = 72) and placebo (n = 70) groups were compared for epidemiologic characteristics, uterine contraction frequency, and incidence of preterm birth. Data were compared by χ2 analysis and Fisher exact test. Results: The preterm birth rate was 21.1% (30/142). Differences in uterine activity were found between the progesterone and placebo groups (23.6% vs 54.3%, respectively; P < .05) and in preterm birth between progesterone and placebo (13.8% vs 28.5%, respectively; P < .05). More women were delivered before 34 weeks in the placebo group (18.5%) than in the progesterone group (2.7%) (P < .05). Conclusion: Prophylactic vaginal progesterone reduced the frequency of uterine contractions and the rate of preterm delivery in women at high risk for prematurity. (Am J Obstet Gynecol 2003;188:419-24.)