Tuesday, May 26, 2015

Pregnancy after stillbirth: notes on CTGs and UTIs

Recently I've been thinking about CTGs and I also mentioned UTIs.   I wanted to put a few words about them on these here posts.

A UTI is a Urinary Tract Infection, like cystitis.  They are uncomfortable/painful at the best of times, causing pain (burning) when you urinate, making you want to pee more often than normal (and crucially, not having anything to piss out when you do go), and can make you feel grotty and under the weather.  In older people (pensioners) they can make you seriously unwell.  When you're pregnant an untreated UTI can cause premature labour and the infection can travel up your vagina, to the womb and infect the baby.  This can cause illness in the baby and can be fatal (to the child).

Hence why my midwife was concerned about the leukocytes and ketones as they can indicate an infection.  However, I did as she told me and the following Monday when my urine got tested again it was all clear.  So that's fine.

CTGs, or Cardiotocography traces, are used to monitor the baby's heartrate and uterine contractions.  It's done through putting two monitors on your bump, one at the top of your uterus (your fundus) and one roughly where the baby's heart is.  The machine my hospital uses gives the uterine contraction rate in a green number, and the baby's heartrate in a red number.  If you ring up your hospital concerned about movements and they ask you to come in they'll put a ctg trace on you.  At my hospital you go into delivery suite to have this emergency check done.  I've been in twice now, it's not pleasant.

Anyway, the point of this post is for me to explain about the baby's heartrate and what the ctg trace is picking up.  I asked a couple of fellow Sands ladies about this and they, along with my midwives, gave me the following information.

My midwives have all said that a normal baby's heartrate is between 110 and 160 beats per minute. When the baby moves, it is expected that the heartrate will go up to to 180 beats per minute (just as yours and mine heartrate would go up if we exerted ourselves by going up stairs, for example).  On a ctg trace, which records the heartrate on paper, a la the top line on this image:
You will expect to see at least two spikes occurring at the same time as movement.  The mother is given a beeper thing to press when she feels movement and this is also recorded on the trace.  These increases are called accelerations.

I believe that the lower line on the above image measures baseline uterine activity, i.e. contractions, and is normal.

The ctg tracking the heartrate will pick up when decelerations, i.e. when the heartrate dips below 110.  If more than two of these happen in a 20/30 minute period for more than 15 seconds at a time your midwife/consultant should be concerned and further monitoring is needed.

You have to meet set criteria for the midwife and doctor to be happy with the traces.  A normal CTG needs 4 features - baseline rate to be between 110 and 160bpm, variability has to be 5bpm or more, at least 2 accelerations in a 20 minute period and no decelerations.

For a non-reassuring trace, you need to meet just one of  the following criteria: baseline heartrate below 109bpm or above 160 bpm, variability less than 5bpm per 40 minutes or more than 5bpm for 90 minutes, unprovoked decelerations, decelerations related to uterine tightenings when not in labour.

A baby's heartrate is expected to vary from second to second, like humans out of the womb but there will be a baseline, which is not the same as a deceleration.  I have been told that decelerations are very obvious on ctgs, and that experienced midwives can hear a deceleration without having to have it checked by technology.  This applies when you have your heartbeat checks at regular antenatal midwife appointments and even the parents attending the appointment can hear it.  Having now heard this baby's heartrate weekly since 16 weeks, I would agree that it is obvious what a normal heartrate of around 140 to 150 beats per minute sounds like.

Note: fellow Sands women who are also midwives have told me that a normal heartrate is between 110-160 beats per minute and they expect accelerations with movements to go up to 180 beats per minute.  They have said a deceleration is classified as being at least 15 beats below the baseline for at least 15 seconds.  Which to me says it comes back to being what it normal for your baby.  One off decelerations can be fine, but the baby should always be monitored with a ctg and/or scan if one is suspected.

Another Sands mother says that when she had hours of CTG in the last 5 weeks of her pregnancy, her son only had decelerations in the day before being delivered, and that they were really really obvious on the CTG feed.  She says that movements led to a raise in heartrate, which then came back down, sometimes with a little valley below the average heart rate.  The deceleration was "massively and very distinctly different, with a marked downwards tench with no movement before it".  I'll add that although the mother might not feel every movement, on a ctg trace and a regular heartbeat check, you can hear movement as the baby pushes or shifts against the uterus.

I also asked Sands women about what they can pick up at scans regarding heartrate.  Most scans don't take 20 minutes.  They might take just ten or less.  I have been told that during a scan the sonologist looks for normal movement patterns and they can see if the heartrate is slow - they check it by eye.  if you have a doppler scan they can record the blood flow through the umbilical cord - the print out looks a bit like the ctg trace.

That's a rather long post, but I feel better for getting it out there.  I'm a huge believer in the more information available to parents the better.

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