Aside from the ill-effects that caffeine may have on your baby-to-be, ingesting it at 12 weeks can cause a host of problems such as elevated blood pressure and dehydration. These effects can be seen throughout a pregnancy. However, during the first trimester, excessive caffeine intake may possibly increase the risk of miscarriage.
The majority of miscarriages happen during the first 13 weeks of pregnancy, according to the March of Dimes. As of 2014, no definitive connection has been made between caffeine and miscarriages. However, a Swedish study detailed in "The New England Journal of Medicine" found miscarriages occurred more often in women who had at least 100 mg of caffeine per day. Dr. Pooja Shah, an OB/GYN at the Banner Baywood Medical Center in Mesa, Arizona, notes that women in their first trimester and beyond should limit overall caffeine intake to less than 200 mg per day.
Perhaps even before you knew you were pregnant, you noticed you had to constantly running to the bathroom. While this is just part of early pregnancy, caffeine can make it worse. While it's commonly thought of as a stimulant, it's also a pretty effective diuretic. That means it increases the need to urinate, and that increases a mother's chances to suffer some dehydration says Shah.
An increased cardiac output — the amount of blood your heart pumps out — is a natural part of early pregnancy that pushes up your pulse rate. Caffeine can enhance that and hike your blood pressure. Small amounts of caffeine will only cause a minimal and temporary spike. However, having more than 200 mg per day — or one 12 ounce cup of coffee — may elevate the heart rate even more.
Drinking more than one cup of coffee — or an equivalent amount of caffeine — can cause sleeplessness. During the first trimester, changes such as an increase in progesterone can make you feel more tired than usual according to the Yale Medical Group. When you couple the fatigue you're feeling at 12 weeks with the up-all-night effects of caffeine, you may exacerbate first trimester tiredness. You may also notice you're overly sensitive to caffeine.
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