ULTRASOUND DATING SCAN

The Crown-rump Length

This measurement can be made between 7 to 13 weeks and gives very accurate estimation of the gestational age. Dating with the CRL can be within 3-4 days of the last menstrual period. An important point to note is that when the due date has been set by an accurately measured CRL, it should not be changed by a subsequent scan.

The Biparietal Diameter

The diameter between the 2 sides of the head. This is measured after 13 weeks. It increases from about 2.4 cm at 13 weeks to about 9.5 cm at term. Different babies of the same weight can have different head size; therefore dating in the later part of pregnancy is generally considered unreliable. Dating using the BPD should be done as early as is feasible.

 The Femur Length

Measures the longest bone in the body and reflects the longitudinal growth of the fetus. Its usefulness is similar to the BPD. It increases from about 1.5 cm at 14 weeks to about 7.8 cm at term. Similar to the BPD, dating using the FL should be done as early as is feasible.

The Abdominal Circumference

The single most important measurement to make in late pregnancy. It reflects more of fetal size and weight rather than age. Serial measurements are useful in monitoring the growth of the fetus.

4D baby scan, Peek inside the womb.

A baby can’t drown in the womb because until they are born they don't breathe air. The umbilical cord is attached to the baby by the placenta, which is attached to the wall of the womb. We can see the placenta & cord on your ultrasound baby scan. The cord passes nutrients and oxygen in and removes waste back to the mother's system for elimination. She does the breathing and eating for the baby. We can see baby drinking the fluid around them, then weeing it out. You can see the umbilical cord with your ultrasound baby scan, the cord floats in the fluid that surrounds baby, it can be clearly seen on 4D scans as a thick black rope, and often appears wraped around baby, its nothing to be worried about, cord rolls around baby and slips off when baby moves all through your pregnancy. Lots of babies enjoy the feel of the cord or placenta on their faces, it’s their first comfort blanket.

In 4D ultrasound scans we need a pool of fluid in front of babies face to get good clear imaging, so we ask mum to drink extra fluid for a week or more before her scan to ensure she is totally hydrated and to encourage better volume of fluid around baby.

The baby is physically protected both by the flesh of the mother and a fluid sac which can deflect any soft impacts and a lot of hard impacts away from the baby. 

Amniotic Fluid, Umbilical Cord

Amniotic Fluid

Attached to placenta is the membranous sac which surrounds and protects the embryo. This sac is called the amnion. It grows and begins to fill, mainly with water, around two weeks after fertilization. This liquid is called Amniotic fluid, it allows the baby to move freely, without the walls of the uterus being too tight against its body. Buoyancy is also provided here for comfort. After a further 10 weeks the liquid contains proteins, carbohydrates, lipids and phospholipids, urea and electrolytes, all which aid in the growth of baby. In the late stages of gestation much of the amniotic fluid consists of babies urine. The baby swallows the fluid and then wees it out to prepare its digestive organs for use after birth. The baby also "breathes" the fluid to aid in lung growth and development.

As with too little fluid, too much fluid or polyhydramnios, can be a cause or an indicator of problems for the mother and baby. Polyhydramnios is a predisposing risk factor for cord prolapse and is sometimes a side effect of a macrosomic pregnancy. In both cases, however, the majority of pregnancies proceed normally and the baby is born healthy.

Umbilical Cord

This is the life support for a growing embryo. The umbilical cord stretches between the placenta and the baby. This cord contains the umbilical arteries and vein. The umbilical cord forms by week 5 of conception. The cord can be 22 to 36 inches long and may have the appearance of a coil. The umbilical cord is very rich in stem cells and is often used for parents who choose to store their stem cells in a blood bank or donate it to a blood bank. These stem cells can be used to treat over 45 disorders and is an alternative from extracting the stem cells from a donor.

During your ultrasound scan you may see that the cord is around baby, we see this in over 80% of scans and it is nothing to be worried about.

The placenta

The placenta is a structure that develops inside the uterus during pregnancy. It forms from the same cells as the embryo and acts as an unborn baby’s life-support system. One side of the placenta attaches to the wall of the uterus and connects to the mother’s blood supply. The other side connects the baby to the placenta through the umbilical cord.

The placenta supplies the baby with nutrients and oxygen from the mother’s blood. It also removes waste from the baby’s blood and puts it into the mother’s blood. The mother’s kidneys dispose of the waste. We check postion of the placenta during your ultrasound scan to ensure its not low lying or covering the way out. 

The placenta also produces hormones that play a role in starting labour and help protect the baby from infections and harmful substances. After a woman gives birth, the placenta’s job is done. It comes out after the baby is born and is called the afterbirth.

The mature placenta is flat and shaped like a circle. It weighs about 1 pound. But sometimes the placenta:

• ·                                           Is not formed correctly
• ·                                           Is not in the right place in the uterus
• ·                                           Does not work correctly

These kinds of placental problems are some of the most common complications of the second half of pregnancy. 

Why it is harmful to smoke during pregnancy

Why it is harmful to smoke during pregnancy

A baby in the womb gets everything from its mother. Nutrients and oxygen come via the placenta and umbilical cord. Smoking not only exposes the baby to toxins in tobacco smoke, but it also damages placental function.

When a person smokes, some of the oxygen in their blood is replaced by carbon monoxide. If a pregnant woman smokes, her blood and therefore her child's blood will contain less oxygen than normal. This can cause the babies heart rate to rise as baby struggles to get enough oxygen. Some times we can see the damage to the placenta with ultrasound scanning.

The particles in tobacco smoke contain different toxic substances that change the blood's ability to work in a healthy and normal manner. This can affect the placenta that feeds the baby.

Babies born to mothers who smoke are more likely to be born prematurely and with a low birth weight (below 2.5kg or 5lb 8oz). and have poorer lung function.

Are twice as likely to die from cot death. There seems to be a direct link between cot death and parents smoking.

Are more likely to get painful diseases such as inflammation of the middle ear and asthmatic bronchitis more frequently in early childhood.

Are more likely to become smokers themselves in later years.

Based on a text by Dr Erik Fangel Poulsen, specialist, and Martin Døssing, specialist