You know you’ll have an ultrasound in your second trimester, but why might your doctor ask you to come back for another? It’s not common, but it’s also nothing to worry about just yet.
Did my doctor miss something?
Your doctor is a qualified and experienced professional, but that doesn’t mean they’re fully sure about everything all the time. Sometimes, additional investigation is needed to be fully safe. If your doctor suspects polyhydramnios (excess amniotic fluid), for example, they’ll ask you to return for another ultrasound one or two weeks after your first one. If your doctor suspects issues related to your cervix — particularly if you experienced such problems in a previous pregnancy — you’ll likely have to come in for an ultrasound every couple of weeks through week 24 or so.
If the ultrasound reveals delayed growth of the baby, you may be prescribed a Doppler ultrasound.
What is a Doppler ultrasound?
A Doppler ultrasound uses high frequency sound waves to get information about your blood flow, as well as the baby’s. It can be used to assess whether baby is getting enough oxygen and nutrients via the umbilical cord.
My doctor said everything is fine. Why would I need additional ultrasounds, in that case?
After your 20th week of pregnancy, each doctor’s appointment will include measurements of your uterus and abdomen, as well as listening to baby’s heartbeat and checking your blood pressure. If at any time your doctor is unsure about these measurements and checks, they’ll likely prescribe an ultrasound. Examples of this would be if your belly is too large or small (to rule out polyhydramnios or too little amniotic fluid) or if baby’s heartbeat is too fast, too slow or irregular. If your blood pressure is high, a Doppler ultrasound may be used to rule out complications associated with preeclampsia.
Sometimes the expectant mama herself may request an ultrasound if she’s noticed baby moving a lot less or not at all.
Are frequent ultrasounds bad for the baby?
Not that we know of [1]. Studies haven’t shown any adverse effects on baby. However, doctors don’t rule out that there may be effects we don’t know about yet, so they’re careful about scheduling them only when needed. If all signs of the pregnancy are normal, there’s no need for a “just in case” ultrasound [2].
