Hey Baby!

Cut the coffee?

For some time there has been a suspicion that coffee is harmful to the unborn baby. Most research on the topic is of rather dubious quality. It is, after all, difficult to be sure about how much women have genuinely consumed (although blood levels of caffeine have been used to confirm diary records) and probably more importantly there may be other factors at play.

We know that women with a high caffeine intake differ from those with low or no caffeine use in many ways. As the latest report in the British Medical Journal (26 January 2007) put it: [women with higher coffee consumption] smoke more, have higher alcohol intake and have attained a lower level of education. These are all independent risk factors for the kind of pregnancy outcomes that we are interested in and worry about, such as miscarriage, premature birth and low birthweight babies.

In early pregnancy there is evidence that higher intake of coffee can almost double the chance of miscarriage, but this is only if you are taking 5 or more cups per day (equivalent to 500mg of caffeine).  One or two cups per day is not linked with miscarriage.

This week's study looked at 1200 Danish women who were drinking more than 3 cups of coffee per day. The researchers gave half of the women decaffeinated coffee to have instead, starting from mid-pregnancy. Total coffeine intake for those who received decaf was overall the equivalent of 3 cups of coffee less than those who carried on as before.

No difference was found between the two groups of women in terms of likelihood of premature labour or having a low birthweight baby. This suggests that switching to decaf is unlikely to have any particular benefit if you drink more than 3 cups per day.

The study wouldn't be expected to pick up differences if reducing coffee earlier than mid-pregnancy was important or if greater reductions were necessary.

Approximate caffeine intake from common drinks is as follows:
Cup of coffee: 100mg
Mug of coffee: 200mg
Cup of tea: 50mg
Glass of cola: 20mg

This study is important as they did check for other factors mentioned above that are known to be associated with premature labour and growth problems. Also, the fact that it is a randomised, planned intervention study makes it more likely to be accurate (as compared to research that analyses population statistics).

It is my recommendation that pregnant women drink no more than 3-4 cups of coffee per day in early pregnancy and to probably limit it to less than 5-6 cups in later pregnancy, recognising that we still don't have complete data to inform us of the exact risks.

IVF overview

The New England Journal of Medicine has a good review article this week about IVF (in vitro fertilisation, or 'test tube' conceptions). Although it is aimed at doctors, most of the piece is pretty readable and it summarises well where we are with this form of infertility treatment.

It opens with the following vignette:

A 37-year-old woman who has never been pregnant and her 40-year-old husband have been attempting to conceive a child for the past 3 years. An infertility evaluation has shown no cause for the difficulty. She is ovulating regularly, and a hysterosalpingogram shows that her reproductive tract is anatomically normal. He has a normal sperm count; he has not fathered any children. They are frustrated and want to proceed with in vitro fertilization. What should you advise?

The article starts with an overview of when IVF is recommended, success rates, a nice diagram summarising the actual procedure of the treatment (full size), and finally some discussion of the risks both to the woman undergoing treatment as well as the risks to the baby conceived.

You can read the article in PDF format (600kB).

Flying in pregnancy

It's a common question - am I safe to fly? Usually the answer is yes, but there are a number of things that you need to be aware of...

Let's start with the least likely of problems - air crashes. The risk of this happening as we all know is pretty low - a mortality rate of between 1 in 400,000 and  1 in 10 million, depending upon the airline you choose. A daily flight for about 1000 years before you can expect a problem (OK, it's a pretty big one if it does happen...) Not bad statistics really, compared to car travel for example (1 in 5000), although that is an US figure, the risks of car travel may be different in NZ.

Premature labour
A study published in the Australia & NZ Journal of Obstetrics & Gynaecology last year suggested that there may be a link between air travel and going into premature labour. Although they did find a link, it was only in first time mothers and resulted in an average gestational age of 36 weeks at birth, as opposed to 39 weeks in those who did not fly. There are a number of other factors that they were not able to take into account (whether women smoked or not, a history of infertility and infections - all of which can put you at higher risk of early delivery), so questions still remain. Interestingly, although women went into labour a few weeks earlier than normal, the flights actually took place on average at 11 weeks of pregnancy - 6 months or so before then. As the authors say, more research needs to be done (as always).

If you were thought to be at high risk of early labour, an ultrasound scan of the cervix (right) can help predict the possibility. If the cervix is more than 2.5cm long, it indicates that early labour is much less likely.

Thrombosis
Deep Vein Thrombosis (DVT) or a Pulmonary Embolism (PE) in the lung are pretty serious and have been in the news re their association with flying, coining the term 'economy class syndrome'. Unfortunately, just being pregnant puts you at higher risk than average. I think it is fair to say that the jury is still out on the exact link between air travel and thrombosis, but there are certainly some things that you can do to reduce the risk.

It is important to drink plenty of fluids, but not alcoholic ones for obvious reasons. Keep mobile during the flight, with regular short trips (as if you need to be told with all those fluids and your pregnancy bladder!). Graduated compression stockings are recommended for women who fly long distance during pregnancy. Some recommend low dose aspirin, but compression stockings are just as effective.

If you have additional risk factors for thrombosis (e.g. a strong family history or a prior thrombosis yourself) then you may need injections to thin your blood. Talk to your LMC about it if you are unsure.

Radiation exposure
This is one of the main reasons that airline companies transfer pregnant flight attendants to ground duty in the first trimester. A transatlantic flight is approximately the equivalent of 2 chest x-rays radiation exposure. This may lead to approximately 1/350,000 additional risk of childhood cancer for the baby. To put this in perspective, the background or 'natural' chance is around 1 in 650 - so although it sounds serious, the additional risk is actually quite small.

Low oxygen
It is true that the oxygen concentration in aircraft is less than on the ground (equivalent to an altitude of 2400m) but the level is more than enough for the baby. A woman who is quite severely anaemic, however, might develop symptoms and need additional oxygen. Your blood count would have to be less than 80 g/l which is not that common, even in pregnancy.

Other things to think about
Finally there are a number of practical things to consider when you are thinking about flying, some relating to where you are going.

• Vaccines - inactive ones are safe, but if the risk of infection is high, even the live ones might be preferable to the disease itself.
• Malaria - chloroquine is known to be safe and unless you are travelling to an area known to be resistant, this would be the recommended anti-malarial.
• Emergencies - for the duration of your flight, you will obviously have minimal access to medical equipment and possibly no access to doctors or midwives (...I am of course available for accompanied flights to the Maldives, Fuji, etc!). In reality the chance of something happening mid-air is pretty small, especially if you are less than 36 weeks.
• Medical care at your destination - are they able to provide a similar level of care to that in NZ?
• Insurance - check you are covered for both yourself and neonatal care - a trip to the US could prove very expensive if you did give birth early and weren't covered.
• Activities at your destination - swimming, walking, hiking etc are all safe, but beware of altitude activities as emergency services may be limited. This is apart from the risk of injury.
• Scuba diving - not recommended during pregnancy and definitely no deeper than 18 metres.

So, once you've got all that covered - have a great trip!

Perineal massage to prevent episiotomy

When it comes to childbirth, one thing guaranteed to make all women cross their legs is the mention of the word 'episiotomy'. Even men shuffle uncomfortably at the thought of it, thanking their lucky stars (just that once, of course) that they miss out on the wonder of giving birth!

An episiotomy is a surgical cut carried out under local anaesthesia as the baby is born. It is used to widen the birth canal enough so the baby can fit through. The cut is made in a downward and outward (usually to the right) direction so that any extension is not in the direction of the anus. Sometimes an episiotomy is done because it is so clear that a significant tear is going to happen, it can be preferable to ensure it is both controlled and in an appropriate outward direction (as opposed to toward the anus). This is not by any means to say that an episiotomy is always better than a tear - most tears are minor - and we know that a 'liberal' approach to episiotomy as opposed to a 'restrictive' one results in more severe tears overall.

The Cochrane Library is an electronic medical resource full of helpful information for health professionals, and the latest version has something useful for pregnant women too. Research has found that perineal massage from 35 weeks of pregnancy can significantly reduce the need for episiotomy during childbirth. Irrespective of whether an episiotomy was done or not, women who did perineal massage were also 30% less likely to experience perineal pain at 3 months after the birth. The benefits were most likely for women who were experiencing their first birth, probably because the perineum is much more elastic in any case after the first baby has been born.

Don't worry, antenatal perineal massage doesn't require a trained masseuse and can be done in the privacy of your own home. The studies used a sweet almond oil based lubricant although other vegetable oil or water soluble one should be fine. Some women involve their partner.

• Wash hands, and find a relaxing place to do the massage (bathroom, bedroom, where ever you are comfortable)
• Sit in a comfortable position. (A warm bath or warm compresses on the perineum for 10 minutes before massage may help with relaxation.)
• Put the lubricant on the thumbs and perineum.
• Place a thumb just inside of the vagina.
• Press downward towards the rectum and to the sides at the same time until a very slight burning, stinging, or tingling sensation is felt
• Hold the pressure for about 1 minute
• Breathe deeply and slowly and try to consciously relax the muscles.
• Keep pressing down with the thumb and slowly and gently massage back and forth over the sides of the vagina in a 'U' movement for 3 minutes.
• Relax and repeat once.

Many recommend this to be done daily from 35 weeks, but the research suggests that twice a week is preferable.

Double trouble!

There is no doubt about it, twins are definitely something special. To many people the idea of twins is very attractive - not only are they very cute, but they also have the advantage of double the reward for only one pregnancy. Unfortunately it's not all gain/no pain - twin pregnancies are more risky for both mum and babies. Most complications of pregnancy are more common with twins (with the exception of going over the due date!) and probably the most common of these is being born early. The average birth gestation for twins is 36 weeks - approximately 4 weeks earlier than singleton pregnancies. The real concern however is those who are born before 32 weeks, because these babies are ones that have the most problems.

Kypros Nicholaides is a Professor of fetal medicine at King's College in London. When I was at medical school there, he was just building the department; now he has an empire, and is one of the major players in fetal medicine, having published a lot of the research into ultrasound screening for Down's Syndrome. Yesterday, I came across a new website of his with some nice images of twin pregnancies, along with a good description of the different types of twins. Twins can either be identical (monozygotic) or non-identical arising from two fertilised eggs (dizygotic) and two thirds of twins are non-identical.

The thing that obstetricians are most interested in when it comes to twins is how the placenta is arranged. Essentially, each baby in his or her own completely separate, dual-layer sac is best (called dichorionic), whereas sharing a single one (monoamniotic) is least favourable. Fortunately, monoamniotic twins are quite rare and indeed most twin pregnancies have a perfectly healthy outcome.

Kypros has other websites about his Fetal Medicine Centre and another site for heath professionals about Down's screening, including a free download of his 11-13 week scan book.

Vaginal discharge and premature babies

Vaginal discharge. Not the nicest of dinner-table conversation topics perhaps, but one that has had medical researchers and obstetricians in something of a quandry for a long time. We know that some vaginal infections can be trouble for babies. Take for example chlamydia - a growing problem in sexually active teens. Technically, chlamydia is an infection of the cervix rather than the vagina, but either way during childbirth it can be passed to the baby and lead to a nasty eye infection.

Group B Strep is a resident vaginal bacteria in around 20% of women, living there quite happily and not causing any concern to anyone. Except that it is the most common childbirth-acquired bacterial infection affecting babies, which can cause meningitis, blood poisoning, handicap and very rarely death. Fortunately, we know of the main high-risk scenarios when this is more likely to happen and recommend antibiotic treatment to prevent mum-to-baby transmission. More on GBS.

Bacterial vaginosis (or BV) is an infection that is heard about less commonly. Of the 20 or so bacteria that live in harmony in the vagina, one of the most common is called lactobacilli (one of the 'friendly bacteria' we are advised to top-up by probiotic drinks). In BV the lactobacilli are replaced by an overgrowth of other bacteria called anaerobes. One researcher called it quite nattily '... a complex alteration of the vaginal ecosystem'.

Some women with BV get a profuse vaginal discharge, others have no symptoms at all. It can cause an odd fish-like odour which is even more potent after intercourse. Depending upon populations studied, up to one third of pregnant women have BV, though it is less common in caucasians.

For the last 15 years or so there has been controversy over whether BV causes late miscarriage or early birth, and secondly whether treating it does any good in prevention. One study found a 3-fold reduction in late miscarriage/early birth when BV was treated. Only this month, others have called for a national screening programme for BV.

My reading of all this indicates that we should be looking for (and treating) BV in the following situations:

• if you have had a previous premature birth (before 37 weeks gestation) - and this needs to be done at around 15 weeks of pregnancy
• if you are underweight (less than 45kg), as this is an independent risk factor for premature birth.
• if you have unusual vaginal discharge

Bon appétit!