What you see on the outside — the general size and shape of your belly — doesn't have much to do with your baby, their health, or their size. A healthy baby can grow regardless of how your belly looks. During your second trimester, your doctor will start taking fundal height measurements.
Your Bump Can't Reveal: How Large Baby Is
A big bump doesn't automatically mean a big baby. “We measure bumps and palpate the abdomen to help gauge how baby is growing relative to gestational age, but bump size has only some relationship with baby's actual weight,” Page says.
The truth is, no-one can judge the size of your baby simply by looking at your belly – not even your doctor or midwife. As your body changes at each different stage of pregnancy, you can't compare yourself with other women. Remember, every pregnancy is unique.
Measuring bigger or smaller than the average is usually perfectly normal. In fact, research suggests fundal height measurements are often off by two weeks in non-obese women. There's always a margin of error when it comes to estimating the exact weight and size of an unborn baby.
This simple math will give you the range your pregnant belly size should be within. For example, belly measurement at 30 weeks should be between 28 and 32 centimeters. If you're 25 weeks along, your belly should measure between 23 and 27 centimeters.
Your Pregnant Belly: Third Trimester (Weeks 28 to 40)
By 28 weeks, your uterus—and your bump—has extended well above your belly button, Duke says. And as baby starts to put on more inches and ounces, they'll continue pushing your belly outwards, creating a sensation of fullness or tightness in your tummy.
A 32 weeks pregnant belly should measure about 30 to 34 centimeters from the top of the uterus to the pelvic bone.
The mother's height and weight impact the weight of the baby at birth - and the father's height and weight have an impact too. Some babies are small because it runs in the family. However, some babies may take more after the mother or the father, rather than being an average of both.
If you're tall your baby has a more growing space than someone who is small. Your womb will tend to grow upwards rather than push outwards, resulting in your bump looking smaller. If you're shorter, there's just less space, which means less room for the baby to grow upwards, so they grow outwards instead.
There are plenty of reasons that a healthy baby may appear small. It could be that there isn't much fluid around your baby. This may make your bump appear smaller, even if your baby is the right size. The position your baby's lying in, and your own height, shape and tummy muscles can all affect the measurement too.
Does my huge pregnant belly mean I'll have a bigger baby? Not necessarily. While some babies are macrosomic and truly are just measuring larger than average, showing early or feeling like you have a huge pregnant belly doesn't mean you're destined to deliver a bigger baby.
For some moms-to-be, constantly touching, patting, rubbing and holding their belly can be soothing. For others, it's a way to feel close to the baby inside. But no matter the reason, rubbing your belly simply makes you feel good.
It is true that on average baby boys weigh more at birth than baby girls, and so this could make the bump for a boy slightly bigger. But this small difference in weight does not change the shape of the bump. The second is the position of the foetus in the womb.
A small belly while pregnant is usually nothing to worry about, especially if you have a small frame or are experiencing your first pregnancy. Your doctor will begin measuring your fundal height around 20-weeks, and if they have any concerns about your belly size, they may conduct additional tests.
If your baby measures smaller than expected, we'll confirm its size with an ultrasound. “Generally, growth restriction is associated with either maternal risk factors, fetal anomalies, or a problem with the placenta – and sometimes a combination of these situations.
Measuring a little big or small is usually a-okay
That number in centimeters roughly equals the number of weeks along you are. But 1 or 2 centimeters in either direction is nothing to worry about — and it doesn't mean that your baby isn't growing fast enough or will be too big to deliver vaginally.
Some babies are large because their parents are large. Parents may pass along this trait to their children. A high birth weight can also be related to the amount of weight a mother gains during pregnancy. Women who gain a lot of weight during pregnancy often give birth to babies who are large for gestational age.
A baby may be large at birth due to genetic factors, the mother's health or, in rare cases, a medical condition that causes the fetus to grow too quickly. Several factors can contribute to large birth weight. For example: the baby's parents' height and stature.
Genetic, nutritional, environmental, uteroplacental, and fetal factors have been suggested to influence fetal growth. Uteroplacental and umbilical blood flow and transplacental glucose and fetal insulin are major determinants of fetal growth.
A note from Cleveland Clinic
If you're told the fetus measures ahead or behind schedule, try not to worry. It usually just means an ultrasound or further testing is needed. The fetus is more than likely developing perfectly.
When do you lose your mucus plug? Most people don't lose their mucus plug until after 37 weeks of pregnancy. In some cases, losing the mucus plug happens days or weeks before your baby's due date. Some people don't lose it until they're in labor.
Symptoms not to ignore when you're 36 weeks pregnant
You have a persistent headache or visual disturbance. If your feet/ankles/hands or face are unusually swollen. You experience vaginal bleeding. You have an unusual coloured discharge.