Irregular Fetal Heartbeat, Missed beats

Hi, thanks for your time in advance. I am 26 weeks pregnant and live in the UK. Had a normal anomoly scan at 20 weeks no problems detected. I have a doppler at home and used this for reassurance with my son (now 14months) due to placenta previa and episodes of bleeding. It was a sanity saver. I have now been using it with this pregnancy and checking baby about once every 2 days up till 20 weeks. The heart always sounded fine, perfect rythm and no missed beats.

After my 20 week scan, around 21 weeks, i heard an irregularity in the heart beat of my baby. This then seemed to disappear for a few days only to come back. Basically the heart beats about 5 beats pauses, 7 beats pauses, 10 beats pauses, 7 beats pauses and so on. The heart rate is around 125-130 when she is resting and can get up to about 140 when active. I cut out caffeine drinks and cut down on chocolate as i had read it could help and the problem seemed to go away for a week. I checked about 3 times a day and it was great. No missed beats. I thought it had gone.

At around 25 weeks it started again, but it seems even worse. I am still having no caffeine and little chocolate, though i have a sweet tooth so have been having fruit and a bit of icecream. I worry my blood sugar may be causing problems? Although nothing is detected in urine sample tests.

Midwives confirmed the missing beat, however typically when they have listened it seems to not be as bad as it can be and only missed say every 25 beats. For the last 4 days a beat has been missed less than every 10 beats consistently. Prior to this there did seem to be some recovery periods i.e she would have the irregularity for around 6 hours then it would go perfect again for a few hours then go irregular again.

I saw a consultant obstetrician on the NHS yesterday who said its normal and not to worry. He didnt check the baby, nor recommend scans just said it happens and that i need not worry, well that is like asking the wind not to blow! I worry the arrhythmia is getting worse although there are no signs of tachy or brachy rhythms. I am so scared that there could be something wrong with the placenta, that she is not getting enough oxygen, that she is growing or that it is affecting her. She does move but not half as frequently as my son. It appears the problem seems worse when she is resting too, when she perks up it doesn't seem as bad, so i worry that she is quiet due the the irregularity. in fact when she is active it appears there are extra beats rather than missed beats.

In case this helps for example the rythm can go: dum dum dum pause dum dum pause dum dum dum dum dum pause, dum dum pause dum dum dum dum dum dum pause. Hard to explain in writing but hte pauses are fairly frequent.

I worry about the frequency of the missed beats, there seems currently to be on average about 20 to 25 missed beats a minute.

Can you offer any advice?

[Dr. Kokil Mathur]

Hi!

Well, usually by 20 weeks the fetal heart rate become regular. However there is a variation in the rhythm every 5-15 beats and this can be perceived as a missed beat. However, yes, it can be an irregularity in rhythm too, as rhythm abnormalities do become obvious by 20 weeks.
The first thing to do is to contact your obstetrician. If at all this is a rhythm problem, then it’s probably due to premature atrial contractions. These usually resolve on their own by the end term. Also if at all there is a serious and persistent arrhythmia either due to a systemic disease or due to a congenital abnormality of the heart then you will need to be referred for a cardiac consultation. Since your scans have been normal, its unlikely that the baby has a congenital heart abnormality. Take care!