key: cord-0729783-ut0k1fe6
authors: Turgut, Ezgi; Ayhan, Sule Goncu; Oluklu, Deniz; Tokalioglu, Eda Ozden; Tekin, Ozlem Moraloglu; Sahin, Dilek
title: Fetal pulmonary artery Doppler evaluation in pregnant women after recovery from COVID‐19
date: 2021-09-16
journal: Int J Gynaecol Obstet
DOI: 10.1002/ijgo.13916
sha: 856613d34faf6c58f6294ed9c9b6a96016d881a1
doc_id: 729783
cord_uid: ut0k1fe6

OBJECTIVE: To evaluate fetal lung development using pulmonary artery Doppler in pregnant women who had recovered from COVID‐19. METHODS: The prospective case–control study included 41 pregnant women who had recovered from COVID‐19 and 43 healthy pregnant women (control group). All the women in the study group had been diagnosed with COVID‐19 and had completed a quarantine period. RESULTS: The demographic data of patients were similar in the groups (P > 0.05). Main pulmonary artery peak systolic velocity was higher and pulsatility indices were lower in pregnant women who recovered from COVID‐19 compared to the controls (P < 0.001, P = 0.001). Acceleration time, ejection time, and acceleration/ejection time ratio (PATET) of the fetal MPA Doppler were significantly decreased in pregnant women who recovered from COVID‐19 (P < 0.001, P = 0.036, and P = 0.002, respectively). The patients who had recovered from COVID‐19 were divided into two groups: those treated with expectant management and those treated in hospital. The pulmonary artery acceleration time and PATET ratio were significantly lower in the group treated in the hospital (P = 0.023 and P = 0.045, respectively). CONCLUSION: Detailed Doppler evaluations of the pulmonary artery may help in evaluating the fetal adverse effects of COVID‐19 disease.

Inadequate lung development leads to neonatal complications, with high mortality and morbidity, especially respiratory distress syndrome (RDS) in newborns. 1 In contrast to amniotic fluid testing, a Doppler exam is a non-invasive method to assess fetal lung maturation. [2] [3] [4] Determining fetal pulmonary artery blood flow acceleration time, ejection time, and acceleration/ejection time ratio (PATET) is a new approach for monitoring pulmonary artery pressure. 2, 3 Previous studies showed that the acceleration time was negatively correlated with pulmonary artery systolic pressure. 5, 6 The COVID-19 pandemic has spread rapidly worldwide, with adverse pregnancy outcomes, including maternal multisystemic organ damage, with hypercoagulation, hypoxia, and an excessive inflammatory response, reported in infected individuals. [7] [8] [9] [10] The aforementioned adverse effects can explain reported complications, such as early pregnancy loss and fetal growth retardation, caused by COVID-19. [11] [12] [13] Although the mechanisms underlying placental transmission of COVID-19 and its associated effects on fetal organs are not clear, fetal vascular malperfusion is the most common finding in placental pathology. 14, 15 Fetal vascular malperfusion may lead to incomplete maturation of fetal lungs and increased pulmonary artery pressure. The aim of the present study was to evaluate the development of fetal lungs using pulmonary artery Doppler in pregnant women who had recovered from COVID-19.

The present study was conducted at Ankara City Hospital between February 1, 2021, and June 30, 2021. The prospective case-control study included 41 pregnant women who had recovered from COVID-19 and 43 healthy pregnant women (control group). All the women in the study group had been diagnosed with COVID-19 by a reverse transcription polymerase chain reaction test and had completed a quarantine period. The quarantine period was 14 days for those discharged from the hospital and patients who were followed up at home. Women with a history of multifetal pregnancies, fetal structural anomalies, and maternal systemic diseases were excluded.

In the control group, pregnant women with symptoms associated with COVID-19 infection (e.g. a fever, cough, sore throat, or myalgia)

were not included.

Written informed consent was obtained from all participants.

Approval for the study was obtained from the Turkish Ministry of Health and Medical Research Ethics Department of the hospital (decision number E2-21-380).

Gestational age was determined by the last menstrual period or first trimester crown-rump length. All Doppler measurements were performed at 28-40 weeks of gestation by the same maternal fetal medicine specialist using a Voluson S10 ultrasound machine C1-5-RS convex probe (1.75-4.95 MHz; General Electric Healthcare). The fetal cardiac four-chamber view was obtained first and then the fetal main pulmonary artery (MPA) was visualized. The pulmonary valves and the bifurcation of the right and left branches of the pulmonary artery were identified. The measurements were obtained by placing the cursor between the valve and the bifurcation of pulmonary artery. When a specific MPA Doppler pattern was obtained, 4 systolic/diastolic (S/D) ratio, resistance index (RI), pulsatility index, and peak systolic velocity (PSV) values were measured by manual or automatic tracing. 16 Acceleration time and ejection time were measured by a manual trace. Acceleration time is the time from the onset of flow to the maximum flow of the PSV and ejection time is the time from the beginning to the end of ventricular systole. The PATET ratio was calculated. 16, 17 In the Doppler measurements, the mean values of three consecutive cardiac cycles were used.

Statistical analysis was enforced using IBM SPSS Statistics 17.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics were given as mean ± standard deviation for numerical data with normal distribution or median and minimum-maximum values for numerical data that do not follow a normal distribution. The normality of the variables was tested with both Shapiro-Wilk and Kolmogorov-Smirnov tests. Groups were compared with the Student t-test and Mann-Whitney U-test. A type-1 error less than 0.05 was considered statistically significant.

The present study included 41 patients who recovered from COVID-19 and 43 control cases. The findings of the Doppler assessments are shown in Table 3 . 

In the present study, low MPA pulsatility index, acceleration time, During fetal lung maturation, pulmonary impedance decreases, and pulmonary artery flow increases, with the ejection flow reaching a peak in mid-systole. In contrast, the ejection flow peaks earlier in patients with high pulmonary impedance. As a result, the acceleration time and PATET ratio decrease, as reported in earlier studies. 5, 6, 18 A study that investigated the relationship between the PATET ratio and surfactant/albumin ratio revealed an inverse relationship between the PATET ratio and neonatal respiratory distress. 18 In another study, the PATET ratio was lower in infants diagnosed with RDS. 5 important issue. [11] [12] [13] 20, 21 In a review on neonatal complications in newborns (n = 67), RDS or pneumonia was observed in 18% (n = 12), low birth weight in 13% (n = 9), asphyxia in 2% (n = 1), and perinatal death in 3% (n = 2) of the newborns. Despite strict infection control and prevention procedures during the birth and separation of the mother and newborn, four newborns, three of whom had pneumonia, were positive for COVID-19, and vertical transmission could not be excluded. 22 The present study has strengths and weaknesses. It was a prospective single-center study, with a standard follow-up protocol.

However, the cases were not evaluated with respect to vertical transmission. In addition, neonatal outcomes could not be presented as they were delivered at different centers.

In conclusion, COVID-19 causes more severe disease in pregnant women compared with non-pregnant women. 20, 21 Many studies have been conducted on fetal adverse effects, 14, 15, 20, 21 but many questions about fetal consequences remain unanswered. COVID-19 infection can have a negative impact on placental tissues and fetal organs. 24, 25 Further studies are needed to clarify the impact of maternal COVID-19 infection on fetal lung development.

The authors have no conflicts of interest.

ET, SGA, and DS conceived the study. ET, EOT, and DO performed the statistical analysis. The management of the trial was overseen by ET, SGA, DS, and OMT. ET drafted the manuscript. All authors contributed to the approved the final manuscript.

Ezgi Turgut https://orcid.org/0000-0002-5509-7888

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Fetal pulmonary artery Doppler evaluation in pregnant women after recovery from COVID-19