Third-trimester abnormal uterine artery Doppler findings are associated with adverse pregnancy outcomes

Association between transabdominal uterine artery Doppler and small-for-gestational-age: a systematic review and meta-analysis

BACKGROUND

The association between uterine artery Doppler (UtA) measurements and small for gestational age (SGA) has not been quantitatively analyzed throughout the whole pregnancy. This systematic review and meta-analysis aims to comprehensively explore the association between UtA measurements and SGA in the first, second, and third trimesters.

METHODS

Studies were searched from Pubmed, Embase, Cochrane Library, and Web of Science. Weighted mean difference (WMD), odds ratio (OR), and relative risk (RR) with 95% confidence interval (CI) were used as the effect size. Heterogeneity of all effect sizes was tested and quantified using I2 statistics. Sensitivity analysis was conducted for all outcomes, and publication bias was evaluated using Begg's test.

RESULTS

A total of 41 studies were finally included in our meta-analysis. In the first trimester, mean PI was significantly higher in the SGA group than the non-SGA group (WMD: 0.31, 95%CI: 0.19-0.44). In the second trimester, odds of notch presence (OR: 2.54, 95%CI: 2.10-3.08), mean PI (WMD: 0.21, 95%CI: 0.12-0.30), and mean RI (WMD: 0.05, 95%CI: 0.05-0.06) were higher in the SGA group. Also, abnormal UtA measurements were associated with the increased odds of SGA (all P < 0.05). In the third trimester, PI z-score (WMD: 0.62, 95%CI: 0.33-0.91) and PI MoM (WMD: 0.08, 95%CI: 0.06-0.09) showed a significant increase in the SGA group. The odds of SGA were higher in the women with mean PI > 95% (OR: 6.03, 95%CI: 3.24-11.24).

CONCLUSIONS

Abnormal UtA measurements were associated with high odds of SGA, suggesting that UtA might be an adjunctive screening method for SGA in the whole pregnancy.

A Review of Roles of Uterine Artery Doppler in Pregnancy Complications

The invasion of trophoblasts into the uterine decidua and decidual vessels is critical for the formation of placenta. The defects of placentation are related to the etiologies of preeclampsia (PE), fetal growth restriction (FGR), and small-for-gestational age (SGA) neonates. It is possible to predict significant vascular events during pregnancy through uterine artery Doppler (UAD). From the implantation stage to the end of pregnancy, detecting changes in uterine and placental blood vessels can provide a favorable diagnostic instrument for pregnancy complications. This review aims to collect literature about the roles of UAD in pregnancy complications. We consider all relevant articles in English from January 1, 1983 to October 30, 2021. Predicting pregnancy complications in advance allows practitioners to carry out timely interventions to avoid or lessen the harm to mothers and neonates. Administering low-dose aspirin daily before 16 weeks of pregnancy can significantly reduce the incidence of pregnancy complications. From early pregnancy to late pregnancy, UAD can combine with other maternal factors, biochemical indicators, and fetal measurement data to identify high-risk population. The identification of high-risk groups can also lessen maternal mortality. Besides, through moderate risk stratification, stringent monitoring for high-risk pregnant women can be implemented, decreasing the incidence of adversities.

Prevalence and determinants of anaemia during third trimester of pregnancy: a retrospective cohort study of women in the northern region of Ghana

Anemia during the third trimester of pregnancy is linked to adverse maternal and fetal outcomes. This retrospective cohort study estimated the prevalence of anemia and its determinants among third-trimester pregnant women in Ghana's northern region. We analyzed 359 pregnant women aged 18-48, drawn at random from 12 health facilities in the Tatale-Sanguli and Zabzugu districts. A questionnaire collected demographic, obstetric, as well as data on medical interventions. Data on hemoglobin (Hb) levels in the third trimester of pregnancy were gathered from antenatal care (ANC) records. Logistic regression models identified the determinants of anemia during the third trimester. The average age was 28.2 (±6.2 years), and their average Hb level in the third trimester was 10.3 ± 1.1 g/dL. There were 259 women whose Hb values indicated anemia, giving a prevalence of 72.1% (95% CI: 67.3-76.6). Among these, 4 (1%), 108 (42%), and 147 (57%) had severe, moderate, and mild anemia, respectively. Anemia status at first ANC registration (aOR = 1.97; 95% CI: 1.14-3.41) and exposure to information on anemia (aOR = 2.85; 95% CI: 1.10-7.43) were strong determinants. Anemia prevalence is high among third-trimester pregnant women in the study area. Strategies implemented to control anemia should be intensified to prevent maternal and neonatal adverse outcomes.

Uterine Artery Pulsatility Index as a Pre-eclampsia Predictor in the 3 Trimesters in Women with Singleton Pregnancies

OBJECTIVE

 To evaluate the mean uterine artery pulsatility index (UtAPI) in each trimester of pregnancy as a predictor of early or late pre-eclampsia (PE) in Colombian pregnant women.

METHODS

 The UtAPI was measured in singleton pregnancies in each trimester. Uterine artery pulsatility index as predictor of PE was evaluated by odds ratio (OR), receiver operating characteristic (ROC) curves, and Kaplan-Meier diagram.

RESULTS

 Analysis in the 1^st and 3^rd trimester showed that abnormal UtAPI was associated with early PE (OR: 5.99: 95% confidence interval [CI]: 1.64-21.13; and OR: 10.32; 95%CI: 2.75-42.49, respectively). Sensitivity and specificity were 71.4 and 79.6%, respectively, for developing PE (area under the curve [AUC]: 0.922). The Kaplan-Meier curve showed that a UtAPI of 0.76 (95%CI: 0.58-1.0) in the 1^st trimester was associated with early PE, and a UtAPI of 0.73 (95%CI: 0.55-0.97) in the 3^rd trimester was associated with late PE.

CONCLUSION

 Uterine arteries proved to be a useful predictor tool in the 1^st and 3^rd trimesters for early PE and in the 3^rd trimester for late PE in a pregnant population with high prevalence of PE.

Uterine artery Doppler for the prediction of outcome in pregnancies complicated by hypertensive disorders of pregnancy

OBJECTIVES

To evaluate, in pregnancies complicated by hypertensive disorders of pregnancy (HDP), the predictive role of uterine artery (UtA) Doppler for pregnancy outcome compared to the definition of preeclampsia (PE) established by ISSHP recommendations.

STUDY DESIGN

Retrospective cohort study including singleton pregnancies diagnosed with HDP, who underwent UtA Doppler assessment at admission in 2011-2017. The study population was classified considering the presence or absence of PE and according to the presence or absence of abnormal UtA Doppler (mean pulsatility index > 95th percentile).

MAIN OUTCOME MEASURES

Pregnancy outcome, maternal and fetal complications, evaluated as composite outcomes (CO), and duration of pregnancy (from admission to delivery).

RESULTS

A total of 311 mother-infant couples was included.The diagnostic ability of the two classifications was analysed comparing the relative likelihood ratio in the Biggerstaff graph. ISSHP definition turned out to be more efficient in detecting maternal adverse CO in comparison to UtA Doppler, relative positive likelihood ratio 1.50 (1.35-1.66) and 1.31 (1.07-1.60). UtA Doppler classification resulted more efficient in predicting adverse neonatal CO than PE definition, relative positive likelihood ratio 2.21 (1.77-2.75) and 1.61 (1.37-1.90). UtA Doppler was significantly associated with delivery at earlier gestational ages both for patients affected by PE and for women affected by HDP without superimposed PE (respectively p = 0.009 and p = 0.037).

CONCLUSIONS

UtA Doppler at HDP diagnosis is a useful bedside marker of fetal/neonatal complications, and is associated with pregnancy duration.

Intrapartum Doppler ultrasound: where are we now?

Intrapartum hypoxic events most commonly occur in low-risk pregnancies with appropriately grown fetuses. Continuous intrapartum monitoring by means of cardiotocography has not demonstrated a reduction in the frequency of adverse perinatal outcome but has been linked with an increase in the caesarean section rate, particularly among women considered at low risk. Available data from the literature suggests that abnormalities in the uterine artery Doppler and in the ratio between fetal cerebral and umbilical Doppler (i.e. cerebroplacental ratio [CPR]) are associated with conditions of subclinical placental function occurring in fetuses who have failed to achieve their growth potential regardless of their actual size. In this review we summarize the available evidence on the use of intrapartum Doppler ultrasound for the fetal surveillance during labor and the identification of the fetuses at risk of intrapartum distress.

Shipp TD, Zelop CM, Maturen KE, Deshmukh SP, Dudiak KM, Henrichsen TL, Oliver ER, Poder L, Sadowski EA, Simpson L, Weber TM, Winter T, Glanc P. ACR Appropriateness Criteria® Growth Disturbances-Risk of Fetal Growth Restriction

Fetal growth restriction, or an estimated fetal weight of less than the 10th percentile, is associated with adverse perinatal outcome. Optimizing management for obtaining the most favorable outcome for mother and fetus is largely based on detailed ultrasound findings. Identifying and performing those ultrasound procedures that are most associated with adverse outcome is necessary for proper patient management. Transabdominal ultrasound is the mainstay of initial management and assessment of fetal growth. For those fetuses that are identified as small for gestational age, assessment of fetal well-being with biophysical profile and Doppler velocimetry provide vital information for differentiating those fetuses that may be compromised and may require delivery and those that are well compensated. Delivery of the pregnancy is primarily based upon the gestational age of the pregnancy and the ultrasound findings. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Prelabor short-term variability in fetal heart rate by computerized cardiotocogram and maternal fetal doppler indices for the prediction of labor outcomes

Objectives: To investigate (i) the association between pre-labor maternal-fetal Dopplers and fetal heart rate short-term variability (FHR STV) with arterial cord blood pH and (ii) the potential value of pre-labor maternal-fetal Dopplers, FHR STV and Dawes-Redman criteria in predicting composite neonatal morbidity at term in a cohort of unselected women.Method: A prospective study in 218 women with term singleton pregnancy in latent phase of labor or due to undergo induction of labor. Data on maternal characteristics, maternal-fetal Dopplers indices and computerized cardiotocography (CTG) findings of FHR STV and Dawes-Redman criteria were collected. Pearson correlation analysis was used to determine the relationship between maternal-fetal Dopplers and FHR STV and arterial cord blood pH. Logistic regression analysis was used to determine which factors amongst maternal characteristics, labor onset, indication of labor induction, estimated fetal weight (EFW), maternal-fetal Dopplers, FHR STV and Dawes-Redman criteria were significant predictors of composite neonatal morbidity and arterial cord blood pH less than 7.2.Result: Of the 218 cases, 12 (5.5%) women were delivered by emergency operative delivery for pathological CTG, and 42 babies (19.3%) had composite neonatal morbidities. Arterial cord blood pH was not associated with maternal-fetal Doppler indices and FHR STV, but rather it was associated with maternal age and body mass index. The composite neonatal morbidity and arterial cord blood pH less than 7.2 were not significantly associated with maternal characteristics, labor onset, indication of labor induction, pre-labor assessment of EFW, maternal-fetal Doppler indices, FHR STV and Dawes-Redman criteria by computerized CTG.Conclusion: In unselected women in latent phase of labor or undergoing induction of labor at term, admission maternal-fetal Doppler indices, FHR STV and Dawes-Redman criteria are not predictive of composite neonatal morbidity.

Does Uterine Doppler Add Information to the Cerebroplacental Ratio for the Prediction of Adverse Perinatal Outcome at the End of Pregnancy?

OBJECTIVE

To evaluate whether the addition of the mean uterine arteries pulsatility index (mUtA PI) to the cerebroplacental ratio (CPR) improves its ability to predict adverse perinatal outcome (APO) at the end of pregnancy.

METHODS

This was a prospective study of 891 fetuses that underwent an ultrasound examination at 34-41 weeks. The CPR and the mUtA PI were converted into multiples of the median (MoM) and the estimated fetal weight (EFW) into centiles according to local references. APO was defined as a composite of abnormal cardiotocogram, intrapartum pH requiring cesarean section, 5' Apgar score <7, neonatal pH <7.10 and admission to pediatric care units. The accuracies of the different parameters were evaluated alone and in combination with gestational characteristics using univariate and multivariate analyses by means of the Akaike Information Criteria (AIC) and the area under the curve (AUC). Finally, a comparison was similarly performed between the CPR and the cerebro-placental-uterine ratio (CPUR; CPR/mUtA PI) for the prediction of APO.

RESULTS

The univariate analysis showed that CPR MoM was the best parameter predicting APO (AIC 615.71, AUC 0.675). The multivariate analysis including clinical data showed that the best prediction was also achieved with the CPR MoM (AIC 599.39, AUC 0.718). Moreover, when EFW centiles were considered, the addition of UtA PI MoM did not improve the prediction already obtained with CPR MoM (AIC 591.36, AUC 0.729 vs. AIC 589.86, AUC 0.731). Finally, the prediction by means of CPUR did not improve that of CPR alone (AIC 623.38, AUC 0.674 vs. AIC 623.27, AUC 0.66).

CONCLUSION

The best prediction of APO at the end of pregnancy is obtained with CPR whatever is the combination of parameters. The addition of uterine Doppler to the information yielded by CPR does not result in any prediction improvement.

Third trimester uterine artery Doppler indices as predictors of preeclampsia and neonatal small for gestational age

Objective: To test the hypothesis that third-trimester uterine artery Doppler (UAD) predicts adverse pregnancy and neonatal outcomes in a high-risk population.Study design: This is a nested case control study of women with singleton gestations referred for a fetal growth ultrasound between 24 and 36 weeks. Third-trimester UAD was performed if estimated fetal weight (Hadlock's chart) was <20th percentile as these patients were considered high risk for poor pregnancy outcomes. The primary outcomes assessed were neonatal small for gestational age (SGA) and hypertensive disorders. Secondary outcomes included pH <7.10, NICU admission, Apgar <7 at 5 minutes, respiratory distress syndrome, hypoglycemia, and a composite (presence of one or more of the secondary outcomes) neonatal adverse outcome. The sensitivity and specificity of the UAD indices for predicting these outcomes were compared.Results: Among 200 women included, neonatal SGA occurred in 91 (46%) neonates, preeclampsia in 21 (10.5%), early preeclampsia in 4 (2%) and a composite adverse outcome in 67 (34%) neonates. Abnormal UAD indices, specifically left uterine artery notching and pulsatile index (PI) >95th percentile, were significantly correlated with an increased relative risk (RR) of a number of outcomes. Left uterine artery notching was significantly associated with SGA, RR 1.76 (1.03-3.04), preeclampsia, RR 2.53 (1.47-4.37) and early preeclampsia, RR 2.88 (1.34-6.20). The PI >95th percentile was significantly associated with SGA, RR 1.83 (1.21-2.76), NICU admission, RR 1.79 (1.14-2.79), preeclampsia, RR 1.98 (1.29-3.03), and early preeclampsia, RR 3.13 (2.54-3.86). The mean UAD PI >95th percentile had the best sensitivity for SGA, but the area under the ROC curve (AUC) was modest (0.60, 95% CI = 0.53-0.67). Left uterine artery notching and PI >95th percentile had similar predictive utility for preeclampsia AUC 0.65, 95% CI = 0.53-0.76 (mean uterine artery PI >95th percentile) and AUC 0.66, 95% CI = 0.54-0.77 (left uterine artery notching).Conclusion: Abnormal third-trimester UAD indices are associated with adverse perinatal outcomes including neonatal SGA, preeclampsia, and early preeclampsia. Though statistically significantly correlated, the predictive value of UAD indices for adverse pregnancy and neonatal outcomes was modest.

Placental volume and other first-trimester outcomes: are there differences between fresh embryo transfer, frozen-thawed embryo transfer and natural conception?

RESEARCH QUESTION

Does mode of conception influence placental volume and other first-trimester outcomes?

DESIGN

This retrospective single-centre case-control study led in Dijon University Hospital included 252 singleton pregnancies (84 IVF with either fresh embryo transfer or frozen-thawed embryo transfer [FET] and 168 natural conceptions). First-trimester placental volume, uterine artery pulsatility index and maternal serum PAPP-A and beta-HCG were measured. Statistical analyses were adjusted for gestational age, the newborn's gender, maternal age, parity, body mass index and smoking status.

RESULTS

Placental volume was significantly greater in the FET group than in the control group (P = 0.043) and fresh embryo transfer (P = 0.023) groups. At birth, fresh embryo transfer newborns were significantly smaller than controls (P = 0.01) and FET newborns (P = 0.008). Postpartum haemorrhage was far more frequent in FET than in controls and fresh embryo transfer group (38.1%, 2.6% and 1.9%, respectively; P < 0.0001). Placental volume positively correlated with PAPP-A, beta-HCG and the newborn's birth weight, and negatively correlated with uterine artery pulsatility index.

CONCLUSIONS

Placental volume and other first-trimester parameters are modified by IVF with fresh embryo transfer and FET compared with natural conception, but with opposite trends. Given the different protocols used for these techniques, hormonal treatment per se may have a major effect on pregnancy outcomes through the modification of placental invasiveness.

The Assessment of Association between Uterine Artery Pulsatility Index at 30-34 Week's Gestation and Adverse Perinatal Outcome

Background:

Given the high prevalence of adverse perinatal outcome in the developing countries and the association between uterine artery (UtA) blood flow and fetal status in the uterine, in the current study, we assess the association between UtA pulsatility index (UtA-PI) at 30–34 week's gestation and adverse perinatal outcome.

Materials and Methods:

This cohort study included 100 pregnant women at 30–34 weeks’ gestation. At baseline, UtA-PI was evaluated with color Doppler through abdominal ultrasound. Then, adverse perinatal outcomes including preterm labor, intrauterine fetal death, preeclampsia, low 5-min Apgar score (<7), low umbilical arterial cord blood pH, admitted to Intensive Care Unit in the first 3 days of birth, low birth weight, infant with low weight, death of newborns, cesarean section for respiratory distress, and meconial amniotic fluid were recorded. Ultimately, the collected data were analyzed using SPSS, version 20.

Results:

The presence of small-for-gestational-age fetuses indicated the highest prevalent adverse prenatal outcome with the incidence of 13.3% and 58.5%, respectively, among pregnancies with normal UtA-PI as well as those with high UtA-PI (P < 0.001). Overall, given that sensitivity and specificity of high UtA-PI were 37.5% and 73.3%, respectively, it could not properly predict adverse perinatal outcome (P = 0.360).

Conclusion:

According to the results, although the incidence of some of adverse perinatal outcomes in pregnant women with high UtA-PI was higher compared to those with normal UtA-PI, this factor alone cannot predict adverse perinatal outcome well. Therefore, this factor may predict these outcomes well, in the subgroups with high-risk pregnancies or with some blood factors or with pregnancy complications.

Perinatal loss at term: role of uteroplacental and fetal Doppler assessment

OBJECTIVE

To examine the associations of uterine artery (UtA) Doppler indices and cerebroplacental ratio (CPR) with perinatal outcome at term.

METHODS

This was a retrospective cohort study conducted at a tertiary referral center that included all singleton pregnancies undergoing ultrasound assessment in the third trimester that subsequently delivered at term. Fetal biometry and Doppler assessment, including that of the umbilical artery (UA), fetal middle cerebral artery (MCA) and UtA, were recorded. Data were corrected for gestational age, and CPR was calculated as the ratio of MCA pulsatility index (PI) to UA-PI. Logistic regression analysis was conducted to examine for independent predictors of adverse perinatal outcome.

RESULTS

The study included 7013 pregnancies, 12 of which were complicated by perinatal death. When compared with pregnancies resulting in perinatal survival, pregnancies complicated by perinatal death had a significantly higher proportion of small-for-gestational-age infants (25.0% vs 5%; P = 0.001) and a higher incidence of low (< 5^th centile) CPR (16.7% vs 4.5%; P = 0.041). A subgroup analysis comparing 1527 low-risk pregnancies that resulted in fetal survival with pregnancies complicated by perinatal death demonstrated that UtA-PI multiples of the median (MoM), CPR < 5^th centile and estimated fetal weight (EFW) centile were all associated significantly with the risk of perinatal death at term (all P < 0.05). After adjusting for confounding variables, only EFW centile (odds ratio (OR) 0.96 (95% CI, 0.93-0.99); P = 0.003) and UtA-PI MoM (OR 13.10 (95%CI, 1.95-87.89); P = 0.008) remained independent predictors of perinatal death in the low-risk cohort.

CONCLUSION

High UtA-PI at term is associated independently with an increased risk of adverse perinatal outcome, regardless of fetal size. These results suggest that perinatal mortality at term is related not only to EFW and fetal redistribution (CPR), but also to indices of uterine perfusion. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Utility of Doppler parameters at 36-42 weeks' gestation in the prediction of adverse perinatal outcomes in appropriate-for-gestational-age fetuses

Aim

To investigate the potential value of Doppler ultrasound and to assess cerebroplacental ratio (CPR) in the prediction of adverse perinatal outcome defined as Apgar score < 7 at 1 minute.

Material and methods

This was a retrospective cross-sectional study in selected pregnant women undergoing an ultrasound examination between 36 and 42 weeks of gestation. We measured estimated fetal weight (EFW), mean umbilical artery pulsatility index (UA PI), mean middle cerebral artery pulsatility index (MCA PI), CPR, and Apgar score in 1 minute. Multiples of medians (MoM) were calculated for MCA PI and UA PI.

Results

The study group consisted of 446 women, 236 were primipara and 210 were multipara. The average age was 29.6 years (range 16–46 years). The average week of delivery is 39.5 weeks of gestation (range 36–42). Mean MCA PI and UA PI were 1.3 (0.1–2.45) and 0.8 (0.39–1.66), respectively. The mean values were 1.03 (0.1–1.9) for MCA PI MoM and 1.04 (0.5–2.1) for UA PI MoM. Primiparas had lower values of MCA PI (1.27 vs. 1.34), MCA PI MoM (1.00 vs. 1.05), CPR (1.62 vs. 1.73), EFW (3479.53 g vs. 3579.25 g) and birth weight (3513.50 g vs. 3617.79 g). For CPR cut-off point of 1.08: sensitivity was (0.945), specificity 0.1, positive predictive values 0.979, negative predictive values 0.04 and accuracy 0.926. The ROC curves for CPR were: area under the curve was 0.52 at CI 95% (0.342–0.698), p = 0.8271.

Conclusion

Screening in pregnancies with appropriate-for-gestational-age fetuses at 36–42 weeks of gestation using Doppler parameters is not useful in the prediction of adverse perinatal outcomes like an Apgar score < 7 at 1 minute.

The large-conductance voltage- and Ca2+ -activated K+ channel and its γ1-subunit modulate mouse uterine artery function during pregnancy

KEY POINTS

The uterine artery (UA) markedly vasodilates during pregnancy to direct blood flow to the developing fetus. Inadequate UA vasodilatation leads to intrauterine growth restriction and fetal death. The large-conductance voltage- and Ca2+ -activated K+ (BKCa ) channel promotes UA vasodilatation during pregnancy. We report that BKCa channel activation increases the UA diameter at late pregnancy stages in mice. Additionally, a BKCa channel auxiliary subunit, γ1, participates in this process by increasing channel activation and inducing UA vasodilatation at late pregnancy stages. Our results highlight the importance of the BKCa channel and its γ1-subunit for UA functional changes during pregnancy.

ABSTRACT

Insufficient vasodilatation of the uterine artery (UA) during pregnancy leads to poor utero-placental perfusion, contributing to intrauterine growth restriction and fetal loss. Activity of the large-conductance Ca2+ -activated K+ (BKCa ) channel increases in the UA during pregnancy, and its inhibition reduces uterine blood flow, highlighting a role of this channel in UA adaptation to pregnancy. The auxiliary γ1-subunit increases BKCa activation in vascular smooth muscle, but its role in pregnancy-associated UA remodelling is unknown. We explored whether the BKCa and its γ1-subunit contribute to UA remodelling during pregnancy. Doppler imaging revealed that, compared to UAs from wild-type (WT) mice, UAs from BKCa knockout (BKCa-/- ) mice had lower resistance at pregnancy day 14 (P14) but not at P18. Lumen diameters were twofold larger in pressurized UAs from P18 WT mice than in those from non-pregnant mice, but this difference was not seen in UAs from BKCa-/- mice. UAs from pregnant WT mice constricted 20-50% in response to the BKCa blocker iberiotoxin (IbTX), whereas UAs from non-pregnant WT mice only constricted 15%. Patch-clamp analysis of WT UA smooth muscle cells confirmed that BKCa activity increased over pregnancy, showing three distinct voltage sensitivities. The γ1-subunit transcript increased 7- to 10-fold during pregnancy. Furthermore, γ1-subunit knockdown reduced IbTX sensitivity in UAs from pregnant mice, whereas γ1-subunit overexpression increased IbTX sensitivity in UAs from non-pregnant mice. Finally, at P18, γ1-knockout (γ1-/- ) mice had smaller UA diameters than WT mice, and IbTX-mediated vasoconstriction was prevented in UAs from γ1-/- mice. Our results suggest that the γ1-subunit increases BKCa activation in UAs during pregnancy.

Ultrasound prediction of abnormal infant development in hypertensive pregnant women in the second and third trimester

The objective was to assess the sensitivities and accuracies of Doppler ultrasound parameters in the second and third trimester of hypertensive pregnancies in determining perinatal outcomes. 1,054 pregnancies were retrospectively categorized into three groups (healthy pregnancies (HP, n = 988), pregnancies of hypertensive women (HypP, n = 30) and high-risk hypertension pregnancies (HRHypP, n = 36), depending on gestational hypertension as well as fetal birth weights and pregnancy outcomes. Systolic/diastolic ratio (S/D), resistance index (RI), pulsatility index (PI) of the bilateral uterine artery, umbilical artery and vein as well as venous flow velocity data were monitored by Doppler ultrasound. At 20–27 and 28–32 gestational weeks, uterine artery PIs and RIs were significantly higher in the HRHypP group than in the HP and HypP patients. At gestational weeks 20–27 and 28–32 left plus right PI data with cut-off values of 2.35 and 1.73 indicated a risk of stillbirth, premature pregnancy termination and a birth weight of less than 2,500 g with sensitivities of 94.4% and 93.1% as well as specificities of 95.2% and 90.1%, respectively.

Doppler screening and predictors of adverse outcomes in high risk pregnancies affected by tobacco

OBJECTIVE

The purpose of this study was to investigate associations between Doppler measurements and adverse outcomes in an obstetric population with high tobacco use.

METHODS

This retrospective study included patients with Doppler data (umbilical systolic/diastolic velocity ratios (S/D), uterine S/D, uterine left/right ratio index (RI)). Receiver operator characteristic curve analysis determined cut-off elevated Doppler indices. Stepwise logistic regression was used to predict adverse outcomes.

RESULTS

338 of 745 patients (45.4%) had adverse outcomes. Doppler artery indices identified significant associations with IUGR, preeclampsia, low birth weight, pre-term birth and composite adverse outcome variable. An elevated Umbilical S/D was 2.1 (95% Confidence Interval (CI): 1.5-2.9; p<0.001) times was more likely to have an adverse outcome. For left uterine artery S/D and nulliparity, the odds ratios were 1.8 (95% CI: 1.3-2.5) and 1.4 (95% CI: 1.0-1.9), respectively.

CONCLUSION

Umbilical and uterine left S/D indices and nulliparity are significant independent predictors of adverse outcomes.

Uterine artery pulsatility index at 30-34 weeks' gestation in the prediction of adverse perinatal outcome

OBJECTIVE

To investigate the potential value of uterine artery (UtA) Doppler at 30-34 weeks' gestation in the prediction of adverse perinatal outcome.

METHODS

This was a screening study in 30 780 singleton pregnancies at 30-34 weeks. UtA pulsatility index (UtA-PI) was measured and the values were converted to multiples of the median (MoM) after adjustment for variables relating to maternal characteristics and medical history that affect the measurements. Multivariable logistic regression analysis was used to determine if measuring UtA-PI improved the prediction of adverse perinatal outcome provided by screening with maternal characteristics, medical history and obstetric factors. The detection rate (DR) and false-positive rate (FPR) of screening by UtA-PI were estimated for stillbirth, Cesarean section for fetal distress, umbilical arterial cord blood pH ≤ 7.0 or umbilical venous cord blood pH ≤ 7.1 and 5-min Apgar score < 7.

RESULTS

The incidence of adverse perinatal outcome was higher in small-for-gestational-age (SGA) fetuses than in non-SGA fetuses, but the majority of cases with each adverse outcome were in the non-SGA group, including about 70% of stillbirths and more than 80% with Cesarean section for fetal distress, low cord blood pH and low Apgar score. The performance of UtA-PI > 95(th) percentile in screening for each adverse outcome was poor with DR of 6-16% and a FPR of 5-6%. The DR of adverse outcome when screening by high UtA-PI was greater in pregnancies complicated by SGA than in non-SGA pregnancies; 24% vs 13% for stillbirth, 15% vs 5% for Cesarean section for fetal distress, 30% vs 9% for low cord blood pH and 20% vs 3% for low 5-min Apgar score, respectively.

CONCLUSION

High UtA-PI at 30-34 weeks' gestation may be useful in the prediction of adverse perinatal outcome in pregnancies with a SGA fetus, however, in the absence of SGA, UtA-PI is a poor predictor of adverse outcome. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Value of third-trimester cerebroplacental ratio and uterine artery Doppler indices as predictors of stillbirth and perinatal loss

OBJECTIVE

Placental insufficiency contributes to the risk of stillbirth. Cerebroplacental ratio (CPR) is an emerging marker of placental insufficiency. The aim of this study was to evaluate the association of third-trimester fetal CPR, uterine artery (UtA) Doppler and estimated fetal weight (EFW) with stillbirth and perinatal death.

METHODS

This was a retrospective cohort study including 2812 women with a singleton pregnancy who underwent an ultrasound scan in the third trimester. EFWs were converted into centiles, and Doppler indices (UtA and CPR) were converted into multiples of the median (MoM), adjusting for gestational age. Regression analysis was performed to identify, and adjust for, potential confounders, and receiver-operating characteristics (ROC) curve analysis was used to assess the predictive value.

RESULTS

When adjusting for EFW centile and UtA mean pulsatility index (UtA-PI) MoM, CPR-MoM remained an independent predictor of stillbirth (odds ratio (OR) = 0.003 (95% CI, 0.00-0.11), P = 0.003) and perinatal mortality (OR = 0.001 (95% CI, 0.00-0.03), P < 0.001). UtA-PI ≥ 1.5 MoM was significantly associated with low CPR-MoM, even after adjusting for EFW centile (OR = 5.22 (95% CI, 3.88-7.04), P < 0.001) or small-for-gestational age (SGA; OR = 4.73 (95% CI, 3.49-6.41), P < 0.001). These associations remained significant, even when excluding pregnancies with SGA or including only cases in which Doppler indices were recorded at term (P < 0.01). For prediction of stillbirth, the area under the ROC curve, using a combination of these three parameters, was 0.88 (95% CI, 0.77-0.99) with a sensitivity of 66.7%, specificity of 92.1%, positive likelihood ratio (LR) of 8.46 and negative LR of 0.36.

CONCLUSIONS

Third-trimester CPR is an independent predictor of stillbirth and perinatal mortality. The role of UtA Doppler, CPR and EFW in assessing risk of adverse pregnancy outcome should be evaluated prospectively.

Uterine Artery Doppler of the Gravid Uterus as a Predictor Identifying At-Risk Pregnancies

Uterine artery Doppler has been a useful aid in the sonographic evaluation of uteroplacental hemodynamics of the gravid uterus. Pulsatility index, resistive index, and systolic/diastolic ratio can be calculated and interpreted in the evaluation of blood flow. The waveform itself can be evaluated for diastolic notching and used to interpret the qualitative appearance of the blood flow. In addition to the hemodynamic characteristics, practitioners have incorporated maternal serum tests to attempt to isolate at-risk candidates. This article summarizes the effectiveness of each methodology, with a primary focus on an at-risk population, since studies of low-risk populations have not demonstrated significant sensitivity for prediction of complications such as pre-eclampsia, placental abruptia, or fetal demise.

Uterine artery Doppler longitudinal changes in pregnancies complicated with intrauterine growth restriction without preeclampsia

OBJECTIVE

The objective of this article is to evaluate the longitudinal changes in uterine artery Doppler pulsatility index (UtA-PI) in pregnancies complicated with early onset intrauterine growth restriction (IUGR).

METHOD

Case-control study comparing UtA-PI from 20 to 34 weeks gestation in pregnancies affected by IUGR at 20 to 28 weeks and confirmed at delivery (cases), matched with 1000 controls. Multivariable analyses were used to estimate the UtA-PI as a function of both gestational age and IUGR severity. Finally, bootstrapping technique was used to internally validate the models.

RESULTS

We retrospectively retrieved 53 cases and 1000 controls. Regression line having log10 UtA-PI as dependent variable was a function of both gestational age and IUGR. UtA-PI decreased with gestational age in both groups. In IUGR group, UtA-PI was higher from 20 weeks onward and the difference with controls increased with gestational age. In fact, at 20 weeks, the UtA-PI ratio between cases and controls was 1.84, but at 30 weeks it rose to 2.05. Finally, the weight at delivery in the IUGR group was also inversely correlated with the UtA-PI values.

CONCLUSION

We presented a reliable multivariable statistical model to evaluate the temporal changes of UtA-PI values as a function of both gestational age and IUGR.

Second- and third-trimester biochemical and ultrasound markers predictive of ischemic placental disease

Ischemic placental disease is a recently coined term that describes the vascular insufficiency now believed to be an important etiologic factor in preeclampsia, intrauterine fetal growth restriction, and placental abruption. Given the increased risk for poor maternal and fetal outcomes, early prediction and prevention of this disorder is of significant clinical interest for many. In this article, we review the second- and third-trimester serum and ultrasound markers predictive of ischemic placental disease. Limited first-trimester data is also presented. While current studies report a statistical association between marker levels and various adverse perinatal outcomes, the observed diagnostic accuracy is below the threshold required for clinical utility. An exception to this generalization is uterine artery Doppler for the prediction of early-onset preeclampsia. Metabolomics is a relatively new analytic platform that holds promise as a first-trimester marker for the prediction of both early- and late-onset preeclampsia.