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| ORIGINAL ARTICLE |
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| Year : 2022 | Volume
: 17
| Issue : 1 | Page : 7-13 |
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Prediction of preeclampsia and adverse pregnancy outcome on the basis of uterine artery doppler
Prerna Anup Patwa1, Gaurav Vedprakash Mishra1, Rohan Kumar Singh1, Megha Manoj1, Rajasbala Pradeep Dhande1, Sonal Singh2, Aditi V Goyal3, Bhagyashree Yewale4
1 Department of Radio-diagnosis, Jawaharlal Nehru Medical College, Wardha, Maharashtra, India
2 Department of Dermatology, Venereology and Leprosy, Ram Manohar Lohia Hospital, Lucknow, Utter Pradesh, India
3 Department of Pathology, Jawaharlal Nehru Medical College, Wardha, Maharashtra, India
4 Department of Obstetrics and Gynecology, Bharatratna Dr Babasaheb Ambedkar Municipal General Hospital, Mumbai, Maharashtra, India
| Date of Submission | 24-Jan-2022 |
| Date of Decision | 12-Feb-2022 |
| Date of Acceptance | 18-Mar-2022 |
| Date of Web Publication | 25-Jul-2022 |
Correspondence Address:
Dr. Rohan Kumar Singh
Department of Radio-diagnosis, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha - 442 001, Maharashtra
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jdmimsu.jdmimsu_36_22
Background: Hypertensive disorders complicating pregnancy are common. Preeclampsia and eclampsia are major causes of maternal morbidity and mortality, particularly in developing countries. With prompt recognition of symptoms and early diagnosis of preeclampsia can lead to improved maternal and neonatal outcome. Numerous tests have been proposed for the prediction of preeclampsia, their results have been inconsistent. We focused to investigate the uterine artery by conducting Doppler ultrasound study in predicting the preeclampsia in women with a high-risk pregnancy. Methods: This prospective cross-sectional observational study was conducted on 195 pregnant women referred to Acharya Vinoba Bhave Rural Hospital, Wardha (India). Uterine artery Doppler was conducted on all women with raised blood pressure referred to the radiology department. The patients were followed up and outcomes such as eclampsia, chronic hypertension, death, neonatal intensive care unit (NICU) admission, low birth weight, and preterm labor association with preeclampsia were measured. Results: The mean age of pregnant women was 26.47 ± 4.96 years old. Preeclampsia was seen in 68 (34.9%) of the women. In the study, maternal outcome such as eclampsia and maternal high blood pressure (HTN) was significantly associated with preeclampsia. Similarly, neonatal outcomes such as low birth weight, NICU admission, and intrauterine growth restriction were significantly associated with preeclampsia. Pulsatility Index (PI) at >1.2 had the highest sensitivity of 64.71%, specificity of 71.65%, positive predictive value of 55%, and negative predictive value of 79.1% to predict preeclampsia than any other Doppler indices. Conclusion: The findings of this study suggest that PI at >1.2 had better validity in predicting preeclampsia compared to resistive index (RI) and Standard deviation.
Keywords: Preeclampsia, pulsatility index, resistance index, systolic/diastolic ratio, uterine artery Doppler
How to cite this article:
Patwa PA, Mishra GV, Singh RK, Manoj M, Dhande RP, Singh S, Goyal AV, Yewale B. Prediction of preeclampsia and adverse pregnancy outcome on the basis of uterine artery doppler. J Datta Meghe Inst Med Sci Univ 2022;17:7-13 |
| Introduction | |  |
Preeclampsia is a pregnancy-associated progressive condition with multisystem involvement. It is typically identified by acquired hypertension accompanied by proteinuria or an onset of hypertension and consequential end-organ functional deficits with or without proteinuria in the latter half of the pregnancy or postpartum.[1] The origin of the disorder is stipulated to be during early pregnancy and typically involves abnormal reorganization of the maternal spiral arteries at the placental location. Recent systematic reviews state that preeclampsia complicates around 4.6% of pregnancies globally.[2]
A meta-analysis of cohort studies comprising more than 1000 subjects evaluated the risk of preeclampsia and its association with the clinical risk factors frequently investigated in the first trimester.[3] Since historical risk components can only identify roughly 30% of women who are likely to develop preeclampsia,[4] utilizing laboratory and imaging techniques in combination with the previous history to estimate the risk of developing preeclampsia is an active field being explored.
A crucial hurdle for modern obstetricians is early recognition of high-risk pregnancies and pursuing the necessary procedures to ameliorate placentation and thereby bring down the prevalence of preeclampsia. Recent meta-analyses support the fact that uterine artery Doppler scanning can help identifying women at a higher risk of preeclampsia.[5],[6],[7] Resistance to the blood flow in the uterine arteries generally decreases as pregnancy advances. Heightened impedance with respect to the gestational age is an early radiographic characteristic of preeclampsia and probably reflects increased downstream resistance as a result of defective differentiation of trophoblast, ensuing in abnormal invasion of spiral arteries and insufficiency of these vessels to remodel into low resistance blood vessels. Two methods of uterine artery Doppler waveform analysis procedures have been utilized for early detection of preeclampsia, in addition to other disorders associated with compromised placentation (viz., pregnancy loss, fetal growth restriction [FGR]): (1) presence or absence of diastolic notching (unilateral, bilateral) of the uterine arcuate vessels and (2) flow waveform ratios (e.g., high resistance or pulsatility index [PI], systolic/diastolic [S/D] ratio).[8]
This study aimed to determine and compare the accuracy of uterine artery Doppler indices (resistance index [RI], PI, S/D ratio, and notching) for the prediction of preeclampsia among gravid women presenting to Acharya Vinoba Bhave Hospital, Wardha, for colour Doppler with clinical suspicion of preeclampsia.
| Methods | | |
Ethical consideration
- Institutional ethical clearance was obtained prior to the start of the study
- Informed consent was obtained from all the patients recruited prior to the start of the study
- Standard of care was provided to all the patients during the study and follow-up.
Study design and source of data
A prospective cross-sectional observational study was carried out for 24 months from October 2019 to September 2021 at the department of Radio diagnosis in Acharya Vinoba Bhave Rural Hospital, Sawangi (Meghe), Wardha.
Study population
The study included 195 patients who presented with raised blood pressure and suspicion of preeclampsia and were subjected to antenatal care (ANC) ultrasound.
Sample size determination
In-patient department and outpatient care patients with clinical suspicion of preeclampsia irrespective of age, duration of history, and etiology were included, it was calculated by formula.[9]
Za/2 = level of significance at 5% level of significance = 1.96
P = Incidence of hypertensive disorder of pregnancy = 10% = 0.1[10]
e = Desired error of margin = 5% = 0.05
C = confidence interval 0.05
N = 138.29 = 138
However, 150 patients were recruited to increase the accuracy of the study and 195 patients were finally collected during the period.
Inclusion criteria
- Pregnant patients with clinically raised blood pressure and proteinuria
- Patients with high suspicion of preeclampsia in their pregnancy.
Exclusion criteria
- All pregnant patients with hypertensive disorders complicating pregnancy getting terminated before 28 weeks were excluded
- Patients who are not willing to participate in the study
- All chronic hypertension cases were excluded from the study.
Data acquisition
After obtaining the informed consent and ethical clearance, patients underwent in-depth history recording through a structured questionnaire followed by ANC ultrasound Doppler evaluation. The patient was explained about the noninvasive/atraumatic nature of the procedure and made to lie down comfortably on the bed. Coupling gel was applied liberally over the abdomen to get a good acoustic windowing. Images were obtained using Aloka Hitachi ultrasound Machine Arietta 70 S, probe with a convex transducer of frequency 3 to 5 MHz Doppler waveform was obtained after localizing the vessels by B mode real-time scanner. Pulsed Doppler was used to get the Doppler signals after localizing the vessels. The maximum Doppler shift frequencies were obtained and various ratios were calculated from each vessel. Doppler examination was done when fetus was in apnoeic state to avoid the influence of fetal respiration on Doppler signals. Uterine artery PI, RI, and S/D ratios (derived automatically by the machine) were recorded on the datasheet. The women were followed till delivery and pregnancy outcomes were obtained from ANC records.
Data analysis
Data were entered into Microsoft excel data sheet and were analyzed using SPSS 22 version software (Chicago, Illinois, U.S.A.). Categorical data were represented in the form of frequencies and proportions. Chi-square test was used as test of significance for qualitative data. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios were calculated from contingency tables. The screening performance of the indices was compared by constructing receiver operating characteristic (ROC) curves and comparing the area under the curves. P = 5% (P < 0.05) was considered statistically significant.
| Results | | |
The study comprised of 195 antenatal women who were followed throughout the pregnancy and their pregnancy outcome was collected. The demographic profile of subjects [Table 1] and [Graph 1] showed the majority of subjects in the age group of 21–25 years (42.6%) with the mean age of the subjects was 26.46 ± 4.96 years; ranging between 18 and 45 years.
[Table 2] shows the distribution of signs and symptoms of subjects. Major signs and symptoms were pedal edema, dizziness, and headache accounting for 71.3%, 52.8%, and 41%, respectively. 49.7% had urine protein on the dipstick test.
In the study, 46.7% of the cases were primigravida and 53.3% were multigravida. 59.0% of the cases were nulliparous, 23.6% of the cases had one previous abortion and 6.2% of the cases had one previous death of the child.
In the study, 36.4% of subjects had preterm delivery, 34.9% had preeclampsia, 3.6% had eclampsia, 0.5% had death, and 6.2% had HTN. The frequency data of different maternal outcomes are summarized in [Table 3].
The blood pressure showed mean systolic blood pressure (SBP) was 136.30 ± 17.57 mmHg (range 110–200 mmHg), mean diastolic blood pressure (DBP) was 89.63 ± 11.55 mmHg (range 70–150 mmHg). Doppler indices of the uterine artery were as follows: mean right and left RI was 0.55 ± 0.17 and 0.56 ± 0.11, respectively (range 0.3–0.9); mean right and left PI was 0.80 ± 0.34 (range 0.4–2.2) and 0.85 ± 0.35 (range 0.5–2.3), respectively; and mean right and left S/D was 1.92 ± 0.52 (range 2.4–5.9) and 1.94 ± 0.49 (range 1.3–6.2), respectively. During the study, it was observed that at right side 10.3% had notch and 14.4% had left-side notch [Table 4].
In the study, 48.2% had low birth weight, 28.2% required neonatal intensive care unit (NICU), 20% had intrauterine growth restriction (IUGR), 2.1% had IUFD, 5.1% had fetal death, and 0.5% had stillbirth. The frequency data of different neonatal outcomes are summarized in [Table 5].
Association analyses
Association between preeclampsia and outcome
In the study, the maternal outcome such as eclampsia and maternal HTN was significantly associated with Preeclampsia. Similarly, the neonatal outcomes such as low birth weight, NICU admission, IUGR, IUFD, and fetal death were significantly associated with preeclampsia [Table 6].
Analysis of validity of pulsatility index in prediction of preeclampsia
In the study, PI at >1.2 had the highest sensitivity of 64.71%, specificity of 71.65%, PPV% of 55%, and NPV of 79.1%. The data are summarized in [Graph 2].
Validity of RI in prediction of preeclampsia
In the study, RI at >0.75 had highest sensitivity of 69.12%, specificity of 62.78%, PPV of 50.5%, and NPV of 79.4%. The data are summarized in [Graph 3].
Validity of standard deviation in prediction of preeclampsia
In the study, SD at >2.85 had the highest sensitivity of 58.82%, specificity of 76.38%, PPV of 57.1%, and NPV of 77.6%. The data are summarized in [Graph 4].
Comparison of RI, pulsatility index, and systolic/diastolic with respect to preeclampsia
In the study, there was a significant difference in RI, PI, and S/D among subjects with and without preeclampsia. However, PI at >1.2 had better validity in predicting preeclampsia compared to RI and SD.
| Discussion | | |
Pregnancy-induced hypertensive disorders are one of the most common pregnancies associated complications; and preeclampsia is known to affect 3%–5% of pregnant females worldwide.[11],[12] It is hypertension with proteinuria which develops after 20 weeks of gestation and is estimated to cause over 60,000 maternal mortality per year worldwide.[11],[13] The pathogenesis of preeclampsia finds it origin in the placenta. It is believed to be caused due to abnormal placentation resultant of abnormal invasion of placental cytotrophoblast by the maternal spiral arteries and hence, placenta plays an important role in the development and regression of preeclampsia.[14],[15] This abnormal placentation can be predicted by the assessment of uterine artery flow which is a combination of placental resistance and perfusion; therefore, recent studies have indicated the use of uterine artery Doppler studies for the evaluation of the same.[16]
During the 1990s and early 2000s, researchers reported a clear correlation between increase in resistance to blood flow in the uterine arteries and an elevated risk of complications in pregnancy,[17],[18],[19],[20] and the reference ranges have been established previously.[21] However, the sensitivity and the PPV of the investigations were below par in predicting unfavorable pregnancy outcomes.[22]
Lees et al.[19] established that the mean uterine artery PI greater than the 95th percentile, estimated at 23 weeks' pregnancy is strongly associated with placental abruption, deficits in fetal growth, preeclampsia, and fetal demise. In similar lines, Papageorghiou et al.[23] described that mean uterine artery PI of more than the 95th percentile (1.63) in the second trimester identified only 41% of the cases of preeclampsia and 16% of cases that were complicated by FGR. In spite of the low sensitivity, it was possible to detect 93% of the preeclampsia cases and 56% of the FGR pregnancies that required deliver before 32 weeks of gestation with the same cutoff values.[23]
Yu et al.[17] examined more than 30,000 pregnancy cases in 2008, and, likewise, found that uterine artery Doppler was useful in predicting cases of preterm preeclampsia, but not the cases that occur at term. According to a recent meta-analysis comprising 18 studies and more than 55,000 pregnancy cases, using uterine arteries PI of more than the 90th percentile in the first trimester it was only possible to identify 47% of the early-onset preeclampsia and 39.2% of early-onset FGR, with a false-positive rate of 7%.[6] The detection of the presence or absence of diastolic notching as an indicator of vascular resistance also has less sensitivity and specificity, especially in the first trimester, when it is a common occurrence in more than half of the cases.[6]
The present study was an attempt to evaluate the effectiveness of the Doppler velocimetry indices in predicting preeclampsia and adverse pregnancy outcome. The relationship between the Doppler velocimetry indices and neonatal/maternal outcome in preeclampsia complicated pregnancy was also explored.
The mean age of the women enrolled in the study was 26.47 ± 4.96 years with the majority of subjects in the age group from 21 to 25 years (42.6%). The mean age of subjects who developed preeclampsia was 27.338 ± 4.8549 years. Razavi et al.[24] found the mean age of 25.4 ± 5.6 and 26.1 ± 5.5 years in the whole sample set and preeclamptic women, respectively. However, a mean age of 32.03 ± 4.11 years (range 22–39 years) was observed by Adekanmi et al.[25]
Majority of the patients in the study were nulliparous 115 women (59%) of which 34 women (29.5%) developed preeclampsia, while in a study by Adekanmi et al.[25] 37 (39.7%) out of 93 women were nulliparous.
It was observed that most patients recruited for the study had pedal edema, followed by dizziness and headache as one of the symptoms accounting for about 139 patients (71.3%), 103 (52.8%), and 80 patients (41.0%), respectively. The mean of the SBP and DBP of the recruited subjects recorded were 136.19 ± 17.66 mm Hg and 89.63 ± 11.55 mmHg, respectively. These findings were in correspondence to the observation made my Rashid et al.[26] where that the majority of the patients 107 (66.0%) had blood pressure <140/90 mmHg.
The Doppler velocimetry parameters of the current study were as follows, the mean resistive index (RI) on right was 0.55 ± 0.17, mean RI on left was 0.56 ± 0.17; the mean PI on right was 0.80 ± 0.34, mean PI on left was 0.85 ± 0.35 and mean standard deviation (S/D) on right was 1.92 ± 0.52, mean S/D on left was 1.94 ± 0.49. Among the group that did not develop preeclampsia, the mean PI (± SD) was 1.11 (± 0.37) and the PI range was 0.70 to 2.75; while the mean PI (± SD) in preeclamptic patients was 1.46 with SD 0.55 and it ranged from 0.65 to 2.80. Among the group that did not develop preeclampsia, the mean RI (± SD) was 0.53 (± 0.16) and the RI range was 0.30 to 0.9; while the mean RI (± SD) in preeclamptic patients was 0.58 with SD 0.15 and it ranged from 0.50 to 0.9. The mean S/D ratio (± SD) for the group that did not develop preeclampsia, was 2.71 (± 0.42) and the S/D ratio range was 2.05 to 4.10; while the mean S/D ratio (± SD) in preeclamptic patients was 3.10 with SD 0.68 and it ranged from 2.05 to 4.95. A significant difference in RI, PI, and S/D among subjects with and without preeclampsia was observed. This is supported by reports by Mallikarjunappa et al.[27] where the three uterine artery Doppler ultrasound parameters were elevated in women with preeclampsia. This finding was also corroborated by Adekanmi et al. and Li et al.'s findings.[25],[28]
On the contrary, Lopez-Mendez et al.[29] observed no significant difference between the RI and PI the vessels of the high-risk women with preeclampsia and in nonpreeclamptic women. This difference in the findings could be a result of difference in the population dynamics, examination protocols, and abnormality limitations which may be different in different populations. Similar results were found in studies performed by Sultana et al. and Aardema et al.[30],[31]
| Conclusion | | |
In high-risk as well as low-risk pregnancies, elevated impedance to blood flow in the uterine blood vessels is associated with a higher risk for ensuing the development of IUGR and preeclampsia. Pregnant women with normal impedance to blood flow in the uterine arteries are rendered with a decreased risk of developing subsequent obstetric complications associated with uteroplacental insufficiency. Altered impedance to the uterine arterial flow in women attending routine ANC detects about 50% of cases that subsequently develop preeclampsia. Anomalous Doppler finding with a sensitivity of approximately 75% is superior in predicting severe compared to mild preeclampsia.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]
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