Background: The ductus venosus

What is ductus venosus flow?

The ductus venosus (DV) is a tiny vein connecting the umbilical circulation directly to the inferior vena cava where 20–30% of the highly oxygenated blood from the placenta bypasses the hepatic circulation and flows through the ductus venosus directly towards the foramen ovale into the left atrium [1].

What is the normal range of ductus venosus?

A statistical analysis of our cohort revealed that DV PIV values less than 0.73 and more than 1.22 were beyond the normal range. The mean S-wave, D-wave, a-wave, and TAMXV values were 31.18, 25.64, 8.68, and 22.72 cm/s, respectively. Conclusions: The value of DV PIV measurements is debated in the literature.

What is DV vessel?

The DV is a fetal vessel connecting the abdominal umbilical vein to the left portion of the inferior vena cava just below the diaphragm. The function of the DV is to shunt the substrate-rich blood coming from the placenta via the umbilical vein to the heart.

What is reverse flow in ductus venosus?

Ductus venosus (DV) reversed flow (RF) is regarded as an indicator of myocardial dysfunction in fetuses with IUGR, and is considered an indication for delivery, even at extremely preterm gestational ages.

What is NT scan in first trimester?

An NT scan is a common screening test that occurs during the first trimester of pregnancy. This test measures the size of the clear tissue, called the nuchal translucency, at the back of your baby’s neck. It’s not unusual for a fetus to have fluid or clear space at the back of their neck.

What is DV in ultrasound?

Background: The ductus venosus (DV) is an intrahepatic end-part of the umbilical vein. Inappropriate first trimester DV Doppler blood flow patterns correspond to a higher risk of chromosomal abnormalities.

What does umbilical vein become?

The fibrous remnant of the umbilical vein forms a cord that becomes the round ligament (ligamentum teres hepatis) in the adult. The supraumbilical falciform ligament encloses the remnant of the embryonic umbilical vein and the accompanying paraumbilical veins in its free edge.

What does the umbilical artery do?

The umbilical arteries carry deoxygenated blood from fetal circulation to the placenta. The two umbilical arteries converge together about at 5 mm from the insertion of the cord, forming a type of vascular connection called the Hyrtl’s anastomosis.

Why does blood bypass the fetal liver?

The fetal circulatory system uses 3 shunts. These are small passages that direct blood that needs to be oxygenated. The purpose of these shunts is to bypass the lungs and liver. That’s because these organs will not work fully until after birth.

Article first time published on

What should be the CRL at 12 weeks?

Our present study, in a large cohort, suggests that 12 weeks’ gestation (CRL > 55.4 mm) is a safe cut-off for decision-making in fetuses identified sonographically as males.

Can we know gender by CRL?

Conclusions: Fetal gender may reliably be determined when CRL ≥ 60 mm (gestational age ≥ 12+2). Male gender may already be reliably determined when CRL ≥ 55 mm (gestational age ≥ 12+0). If CRL < 50 mm (gestational age < 11+4) the gender cannot be reliably predicted.

When does ductus venosus close?

After birth, the ductus venosus generally closes between days of life 2 to 18 in term infants [2-5]. The natural decrease in portal venous pressure after birth contributes to the closure process [6-8].

What is the normal Cerebroplacental ratio?

6–8. Cerebroplacental ratio (CPR) has been studied and suggested as the most efficient vascular index to detect the above-mentioned fetal redistribution patterns. 9–12.

What is the meaning of nuchal translucency?

Definition. The nuchal translucency test measures the nuchal fold thickness. This is an area of tissue at the back of an unborn baby’s neck. Measuring this thickness helps assess the risk for Down syndrome and other genetic problems in the baby.

What is normal nuchal measurement?

What is a normal nuchal translucency measurement? An NT of less than 3.5mm is considered normal when your baby measures between 45mm (1.8in) and 84mm (3.3in) . Up to 14 weeks, your baby’s NT measurement usually increases as they grow.

What does DV stand for in pregnancy?

Ductus venosus (DV) Pregnancy Screening.

Is uterine artery present in males?

By term, the uterine artery PI for males in complicated pregnancies had returned to normal values. In contrast, the uterine artery PI for females in complicated pregnancies was elevated compared to normal pregnancies throughout gestation and, unlike the male complicated pregnancies, remains elevated at term.

Why is the ductus venosus important?

The ductus venosus is a shunt that allows oxygenated blood in the umbilical vein to bypass the liver and is essential for normal fetal circulation. Blood becomes oxygenated in the placenta and travels to the right atrium via umbilical veins through the ductus venosus, then to the inferior vena cava.

Is NT scan painful?

The scan shouldn’t be painful but you may feel some pressure as the sonographer presses on your abdomen to get a clear picture. Occasionally it can be difficult for the sonographer to get a clear scan from an abdominal ultrasound, in which case a vaginal ultrasound will be offered.

How can you tell boy or girl from NT scan?

We can tell the sex of the baby at the 12 week scan by assessing the direction of the nub. This is something that can be identified on babies at this stage and if it points vertically then it is likely to be a boy. If it points horizontally then it is likely to be a girl.

How much does a nuchal scan cost?

GestationSingle ScanTwin Scan12 to 14 weeks$250$320

Where do umbilical arteries go?

The umbilical arteries surround the urinary bladder and then carry all the deoxygenated blood out of the fetus through the umbilical cord. Inside the placenta, the umbilical arteries connect with each other at a distance of approximately 5 mm from the cord insertion in what is called the Hyrtl anastomosis.

How serious is single umbilical artery?

About 2 in 10 babies (20 percent) with a single umbilical artery have health problems, including heart, kidney or digestion problems and genetic conditions.

What do the umbilical arteries become after birth?

After birth, the proximal portions of the intra‐abdominal umbilical arteries become the internal iliac and superior vesical arteries, while the distal portions are obliterated and form the medial umbilical ligaments.

How do I find my umbilical vein?

Identify the umbilical vein: thin walled, patulous, compared to the thick-walled, smaller calibre arteries. Insert the tip of an iris forcep into the lumen of the vein. Gently and repeatedly dilate the vein by allowing the forceps to spring open.

Do adults have umbilical veins?

Despite this, it has been shown that the adult umbilical vein can be cannulated in a superficial position in the upper abdomen, and through it direct access to the portal venous system can be obtained.

What is ligamentum teres a remnant of?

The ligamentum teres is the remnant of the umbilical vein working throughout fetal life. Initially a pair of the umbilical veins entered the sinus venosus.

What is the last organ to develop in a fetus?

Almost all organs are completely formed by about 10 weeks after fertilization (which equals 12 weeks of pregnancy). The exceptions are the brain and spinal cord, which continue to form and develop throughout pregnancy.

Does a mother share blood with her baby?

Oxygen and nutrients from the mother’s blood are transferred across the placenta to the fetus. The enriched blood flows through the umbilical cord to the liver and splits into three branches. The blood then reaches the inferior vena cava, a major vein connected to the heart.

How can I increase my blood flow during pregnancy?

1. Exercise. …
2. Spice up your diet. …
3. Get a weekly massage. …
4. Avoid sitting all day. …
5. Avoid tight clothing. …
6. Wear compression stockings. …
7. Change your sleeping position. …
8. Stretch.