Product Launch! - The "hi! Baby Sounder" - Your at Home Fetal Doppler
Learn more about how our handheld Doppler can make your pregnancy feel safe.
By Myrah M.
There are two main reasons for not picking up a fetal heartbeat with the doppler. One is not using sufficient conductive gel, which is easily solved by using more gel. The second is that the doppler probe is not being held sufficiently close to the baby’s heart. To confirm that the doppler itself is working, you could place the wand over your own heart. You should hear your own heartbeat very easily.
Next, and the part that can be tricky - you need to determine your baby’s position. At and beyond 16.5 weeks, a baby may move out of range frequently, meaning you might have it for one minute and the next minute you can’t find them.
You should be able to feel the outlines of your uterus in your abdomen at this stage, with the fundus (top) of the uterus somewhere just below your belly button, and the sides about 4-6” (10-15cm) wide in an inverted pear shape. At this point your baby is still very small, with an even smaller heart - so finding the right spot is where the challenge lays.
In the early second trimester, the baby is still small enough that it could be anywhere in your uterus, so just start in the middle near the top and move slowly in a circle like you’re using a joystick. See if you hear anything faintly and then move the wand towards that sound. It should sound like a “ta-tok” sound, but you may hear something more like a “shh.” The frequency should be between 120-160 beats per minute, or counting by 15 second increments, 30-40 beats. If you hear something slower than that and it sounds like “shh” it’s likely you’re hearing your own heartbeat through an abdominal artery. Be patient, even for experts at this stage it might take a few minutes to find. Know that the next time you go to look the baby may be in a completely different spot.
In the third trimester, finding the baby’s heartbeat means finding the baby’s back and shoulders. At this time, the baby should be big enough to be able to feel its position from the outside. Start by palpating the edges of the uterus and see if one side feels firmer or fuller than the other. The side that feels fuller is likely where the baby’s back is. If you feel lots of small movements on one side, likely the back is on the opposite side.
In the early third trimester (26-30 weeks gestation) it’s possible the baby may still be lying transverse, that is, with the head on one side laying horizontally in your abdomen rather than vertically. Don’t be afraid to push firmly with your fingers and thumbs to try to find an outline of a baby–at 26 weeks it may feel about the size and shape of an large head of kale, (~2 pounds), at 30 weeks more like a large cantaloupe, (around 3 pounds). Remember - babies are all folded up and cozy inside your uterus. You may be able to tell which side the head is on, but it’s less likely until the baby is bigger. Start by placing the wand about ¾ of the way to one side along the long edge of the shape you feel. If you don’t find it after moving slightly around and orienting the wand in various directions (like a joystick), try ¾ of the way to the other end. If you hear something that is in the frequency of 120-160bpm but it sounds like “shhh shhh shhh,” you have likely found the placenta or the umbilical cord. While this may be reassuring because it confirms the heart beat, keep looking until you find the more defined “tok” or “ta-tok” sound of the heart to confirm the position of the baby.
Later in the third trimester, it is possible to more definitively determine the position of the baby. First you distinguish the back of the baby, as described above, and from there you can find the “poles” of the baby, which are the head and bum. Try to grasp each between thumb and forefingers and give it a bit of a wiggle. When wiggling the bum, the whole back/body of the baby will move within your abdomen. When wiggling the head, just the head will move side to side. Locate the baby’s heartbeat where you’d expect the back of the neck to be: just adjacent to the head and on the side where the back is lying.