reverse end diastolic flow, REDF), urgent referral for specialist care is needed to avert a perinatal death. absent end diastolic flow, AEDF) or reversed (i.e. Дoppler ultrasound can be used during pregnancy to detect blood flow within the blood vessels of the umbilical cord as a proxy measure of placental function. Undetected IUGR increases the risk of serious fetal complications, making the detection and management of IUGR prior to birth crucial to preventing adverse perinatal outcomes. Despite the high prevalence of IUGR in many LMICs (up to 19% of live births in LMICs are small-for-gestational age), it is often not detected during routine antenatal care. Placental insufficiency is the leading cause of IUGR, mostly due to poor uteroplacental blood flow, placental thrombi and infarctions. IUGR is also associated with higher rates of neonatal death, perinatal morbidity and non-communicable diseases (such as diabetes) into adulthood. It is a well-established risk factor for stillbirth, and can increase the risk of stillbirth by up to eightfold. However, the prevalence of small-for-gestational-age (many of whom are growth restricted) is nearly 20% in low- and middle-income countries. The incidence of IUGR is difficult to estimate, varying between populations, settings and definitions used. Intrauterine growth restriction (IUGR) describes a pathological inhibition of fetal growth that prevents the fetus from attaining its growth potential. Further research on abnormal umbilical blood flow in pregnant women in low- and middle-income countries is required.ДЄn estimated 2.6 million stillbirths occur every year worldwide, 98% of which occur in low- and middle-income countries (LMICs). However we found limited evidence from low- and middle-income countries, where rates of growth restriction and preventable stillbirth are quite high. Across all studies, 55 women experienced absent of reversed blood flow in the umbilical artery, all of which occurred in just six studies. We found 42 studies reporting on over 18,000 women, mostly from high-income countries. women without significant medical, obstetric or fetal complications of pregnancy). We were interested in how often this occurred in women who had a singleton, low-risk pregnancy (i.e. In this review, we aimed to determine how often pregnant women experience abnormal umbilical flow during pregnancy, in particular the occurrence of absent or reversed flow. If the flow is absent or reversed, the baby may die. Poor umbilical blood flow can lead to a baby experiencing growth restriction. When this blood flow is restricted, absent or even reversed, the health of the baby can be threatened. There are insufficient data from lower-income countries and further research is required.Дoppler ultrasound can be used during pregnancy to determine how well blood is flowing through the umbilical cord. ConclusionsД®vidence from largely observational studies in higher-income countries suggests that AEDF and REDF are rare among low- and unselected-risk pregnant women. There was limited evidence from low- and middle-income countries. Four of these studies were in unselected-risk women and five were conducted in high-income countries. However, 55 AEDF or REDF cases were identified from just six studies (prevalence 0.08% to 2.13%). Thirty-six studies reported zero AEDF or REDF cases. ResultsДЄ total of 42 studies (18,282 women) were included. Two authors assessed eligibility and extracted data on primary (AEDF and REDF) and secondary (fetal, perinatal, and neonatal mortality, caesarean section) outcomes, with results presented descriptively. All randomized or non-randomized studies reporting AEDF or REDF prevalence based on Doppler assessment of umbilical arterial flowвЂ‰>вЂ‰20В weeksвЂ™ gestation were eligible.

We searched PubMed, Embase, CINAHL, CENTRAL and Global Index Medicus with no date, setting or language restrictions. In this systematic review, we aimed to synthesise available data on the prevalence of AEDF or REDF. This may be related to fewer events of abnormal Doppler flow, however the prevalence of absent or reversed end diastolic flow (AEDF or REDF) in such women is unknown. While Doppler ultrasound screening is beneficial for women with high-risk pregnancies, there is insufficient evidence on its benefits and harms in low- and unselected-risk pregnancies.

Doppler ultrasound pregnancy