It is pretty uncommon to be “showing” at 8 weeks with a first baby, but not that unusual with subsequent ones. After the first, your abdominal muscles may not be as good at holding it all in, and your tummy can stick out sooner. Still, 8 weeks is pretty early to “show.”
Common reasons for being bigger than expected include:
- wrong due date—you could be further along in the pregnancy than you think
- twins or other multiples
- benign fibroid tumors on your uterus, which can grow from the hormones of pregnancy (and can be seen on ultrasound)
- excess weight gain, where the larger size is really your abdomen and not the uterus
- bloating from constipation or lactose intolerance (Pregnancy hormones can cause constipation, and many women change their diets in pregnancy to include more milk products.)
Your doctor or midwife can get a sense of which of these is likely at your prenatal appointment. If your uterus seems big, an ultrasound will help determine the cause.
In your situation, the problem may be that you (and not just your uterus) are getting bigger. Excessive weight gain can increase the risk of gestational diabetes (GD), excessively large babies, and Cesarean birth. Early on, many moms-to-be need to eat constantly to ward off nausea. That weight gain usually slows down after the first trimester when the nausea abates. But some moms just eat too much throughout pregnancy. Remember that even though you are “eating for two,” one of you is only the size of a walnut! Overall the excess calories needed in pregnancy amount to an extra apple and yogurt each day.
This might be a good time to look at your energy balance. Weight gain comes from the balance between calories out (your basal metabolism plus activities) and calories taken in, although some weight gain in pregnancy results from water retention. Recommended weight gain for average weight women is 25 to 35 pounds over the nine months, generally 7 to 10 pounds in the first half of the pregnancy and 1/2 pound to 1 pound each week in the second half. So you are a little ahead of schedule already! Underweight women and those carrying twins should gain more, and overweight women should gain substantially less. Women who start off obese (with a BMI over 30) are now recommended to keep their weight gain under 15 pounds.
What can you do about excess weight gain? Start now increasing your activity levels every day. For healthy women with normal pregnancies, exercise is good for Mom and Baby. Guidelines include staying well hydrated, keeping cool, and not working so hard that you can’t talk. That’s it! So even women who are not gaining excess weight should consider regular exercise, and women gaining excess weight can use activity to help them control their energy balance.
As for diet, whole books have been written on what to eat during pregnancy, but much of the information is not based on good science. What we do know is that a healthy balanced diet is a good place to start: lots of vegetables and fruits, protein at every meal, and complex carbohydrates. Water and nonfat milk are your best drinks. Stay away from fruit juice and soft drinks, which contain a lot of calories and don’t provide much in the way of nutritional benefits. And if we all can just learn to eat when we are hungry, stop a bit before we are full, and not eat for the wrong reasons (boredom, temptation, pleasing someone else, etc.), we would have good eating habits that could last a lifetime!
That said, I can’t tell from your question why you are bigger than expected. Your doctor or midwife can help you figure this out at your next prenatal appointment.