This is a commonly asked question and the answer can vary, depending upon the circumstances. For example, are you lying down with your baby, or is s/he lying down in your arms? Is your baby being breastfed or formula fed? The concern with this position is that if your baby is lying down, fluid can enter the ear canal and possibly cause an infection.
For most breastfeeding mothers, the answer is simple. If you think about it, your child is likely lying down while eating, even in your arms. So yes, you can nurse your baby while lying down too. Breastmilk has a high level of antibodies in it, and there is no research that shows an increase of ear infections due to positioning. In fact, no matter what position your baby is in while feeding, breastmilk will help decrease infection. So go ahead and put your feet up while you nurse your baby, without worry. If you choose to co-sleep, please follow the recommendations for safely sleeping near your baby.
The answer differs for formula and bottle feeding. In this case, never feed your baby while s/he is lying down. Even in your arms, it is important to keep your child at a minimum of a 30-degree angle. This is because milk from a bottle comes out much faster than it does from a breast, so it can increase the chance of baby choking. Milk can also pool in baby’s mouth and eventually go into his/her ear canals. While breastmilk prevents infection, this is not the case with formula. There is actually an increase in ear infections among babies that are fed formula within the first year, as compared with those that are breastfed, and feeding positions are partially responsible for this. If possible, try to keep your baby upright for about 30 minutes after feeding to prevent regurgitation and reflux, as this also contributes to ear infections.
Follow these simple guidelines and hopefully, your baby will be free of ear infections, and you will get some much-needed rest throughout the first year!