Is preeclampsia in pregnancy preventable?

A few days ago I had to do a caesarean section for a young lady in her first pregnancy. She was only 28 weeks into her pregnancy. Unfortunately she had developed severe preeclampsia, a condition of the placenta characterised by high blood pressure, swelling and protien in the urine. She had underlying essential hypertension which was probably inherited and subsequently developed this condition. As her blood pressure became uncontrollable despite all medications, I made the decision to deliver her as it would otherwise have endangered her life and that of her baby.

There have been many proposals put forward over the years to prevent this condition but none proven. These include, a high protein diet but the World Health Authority concluded that in the abscence of a deficiency it would not be of benefit. Fish oil supplementation once proposed but subsequent trials have shown no benefit. There are more ongoing studies in New Zealand and Scandinavia. Calcium supplementation was shown initially to have some benefit in small trials but a large trial published by the New England Journal showed that there was no benefit in 1997. Low dose aspirin has been shown to have some benefit in those who have had previously had a pregnancy with preeclampsia and at risk in subsequent pregnancies so this may be of benefit but only on hindsight. The most recent study by the British Medical Journal showed that high doses of L-arginine together with anti-oxidants are of benefit but further studies need to be done.

www.eurekalert.org/pub_releases/2011-05/bmj-nss051811.php

How many caesarean sections is safe

It is a common belief that if you have had one caesarean section, you can only have only one more child if it is also by caesarean section. I believe that this misconception arose from the time of "two is enough" family planning policy in Singapore, and those who had a caesarean section were encouraged to have their tubes tied after their second caesarean section. In actual fact one can have as many children as one wishes by caesarean section and I have personally done six caesarean sections on one woman. The risks however increase with each caesarean section although a great deal depends on who performed the operation and the healing process that takes place afterwards.

The main risk is that the placenta implants on the caesarean section scar and this results in a placenta that is low down in the womb and one that becomes difficult to remove during the operation and the possibility of heavy blood loss. The other main risk is that with each operation there may be sticking of the bladder to the womb and injury may occur during the operation. During the second caesarean section, your obstetrician will most likely be able to advise you as to whether you would be able to have more children.

Ectopic pregnancy

The incidence is low 1:700 and unless there is a history of pelvic infection causing some damage to the lining of the fallopian tubes, an ectopic pregnancy is not common. Ectopic pregnancy is a pregnancy that is outside the womb. It can be on any portion of the fallopian tube or even grow on the ovary. This abnormal location of the pregnancy means that it is not possible for the pregnancy to grow to full term and needs to be removed. The risks with an ectopic pregnancy are that as it grows in the tube, it will erode through the tube and rupture a blood vessel resulting in bleeding into the abdomen.

Thus the importance of an early check-up with the obstetrician as he will be able to diagnose an ectopic pregnancy before any serious mishap. Unfortunately an ectopic may be difficult to view on ultrasound scan but will be suspected if there is no pregnancy sac in the womb, and blood pregnancy hormone levels show a slow rise. Sometimes the sac can be seen in the tube and it will give the typical vivid appearance of surrounding blood vessels called the 'ring of fire'.

Diagnosis is by laparoscopy ( inserting a telescope through the belly button) and viewing the fallopian tubes. Treatment is either removing the pregnancy alone by cutting open the afected tube, or removing th entire tube if it is too badly damaged. The alternative is to use a cancer drug to try and dissolve the pregnancy.

Syphillis and pregnancy

Syphillis is a sexually transmitted disorder. With the rising incidence of sexually transmitted disorders especially in China, routine screening during pregnancy is important. Syphillis may have no symptoms especially in the early stages but the infection can cause sudden death of the foetus after 28 weeks. If it is not screened for and therefore missed would be a travesty as if detected, a single dose of penicillin antibiotic would avoid a stilbirth due to this sexually transmitted disorder.

Why you should sleep on your left side

A recent article  showed that sleeping on the back and right side predisposes to a higher incidence of sudden death of the foetus. Although further studies need to be done, it would be prudent to follow this rule especially if you are in your third trimestor. The incidence of stilbirth is not high and is less than 1: 10000. Very often it is attributed to a cord accident but in a large proportion no obvious cause is found. It may be that sleeping on the back and right could well be a cause. Pregnant women have always been told to sleep on the side and the reason is that there is a major vessel running parallel to the spine on the right and behind the womb. As the womb expands there will be increased pressure on this vessel. This blood vessel also supplies the foetus with oxygen and nutrition. The womb is naturally tilted to the right, thus it would make sense that sleeping on the right and back would increase the pressure on this vessel possibly reducing the oxygen to the foetus.
So always remember to sleep on the LEFT side!

http://www.medscape.com/viewarticle/744648?sssdmh=dm1.695983

Down's Syndrome and other chromosome abnormality testing

With more women having children after the age of 35 years, testing for Down's Syndrome ( Mongolism ) and other chromosome abnormalities has become even more important. The test with the highest accuracy of course would be the amniocentesis, however this is an invasive procedure and it would not be practicle to perform this on every pregnant woman above 35 years. Testing has evolved from the triple test (measuring 3 markers in the blood at 15 weeks onwards ) to tests which are done in the first trimestor ie 11 -14 weeks.

In my practise, I will start with looking for the nasal bone between 11and 14 weeks. An absent nasal bone is strongly suggestive of a chromosome problem.  I will do two tests. The first is the measurement of the nuchal translucency ( this is the fluid at the back of the foetal neck which is present in all foetus's but is greatly increased in one with a chromosome disorder ). This should be <2.5mm. There are false positives and I increase the accuracy by combining this test with measurement of 2 markers in the blood, one a hormone beta-HCG and a protein PAPP-A. The combination of these tests is called the Oscar test. This gives a predictive accuracy of 95% for a chromosome abnormality.

If the tests are positive then an amniocentesis or CVS is offered. The alternative is to retest with a triple test and nasal bone measurement at 16 weeks, and if positive an amniocentesis should be done as the likelihood of a chromosome abnormality is high.

Normal delivery or caesarean section?

Obstetricians have always been taught that normal delivery was best, unless there was an indication for a caesarean section. It was assumed that every pregnant woman would want to have a normal delivery. But is normal delivery really better? The caesarean section rates have always been on the rise and now account for about 1 in 3-4 deliveries. I would say that after 25+ years of practising obstetrics, it would appear to me that a caesarean section delivery has a lot more going for it than a normal delivery. I will probably be shot down by many fellow obstetricians for this statement. However I have seen way more complications arising from a normal delivery than caesarean sections. Many pregnant women are unaware that a normal delivery has a higher risk to the baby ( this is only logical since a baby would be more prone to foetal distress having to traverse the female pelvis in its passage to this world, and a long labour may leave both mother and baby exhausted and more prone to potential hazards ). One would argue that recovery is faster with a normal delivery. This may not necessarily be true for a long labour or one with multiple vaginal tears.

Pregnant women now want to be more involved in decision making with regard to mode of delivery and this is a good thing so that a proper informed decision can be made. The obstetricians role is now more of a facilitator and educator in the antenatal care and delivery of the baby. Having weighed the pros and cons joint decisions are made, sometimes even with the input of of various family members.