Pregnancy Loss Symptoms and Diagnosis Is Miscarriage Imminent If hCG Is Not Doubling? By Krissi Danielsson Krissi Danielsson, MD is a doctor of family medicine and an advocate for those who have experienced miscarriage. Learn about our editorial process Krissi Danielsson Medically reviewed by Medically reviewed by Meredith Shur, MD on April 20, 2020 Meredith Shur, MD, FACOG, is board-certified in obstetrics and gynecology, as well as a certified medical examiner. Learn about our Review Board Meredith Shur, MD Updated on August 28, 2020 Print Most pregnancy journeys begin with a positive urine test. Pregnancy tests detect a telltale sign of pregnancy: rising levels of human chorionic gonadotropin (hCG), a hormone produced by the placenta. During the start of a normal pregnancy, the levels of hCG increase rapidly—doubling every two to three days in the first four weeks. Seeing those numbers rise can be comforting, but what if your hCG level isn't doubling? Many pregnant women worry that this is a sign of an impending miscarriage. However, hCG doesn't tell the whole story. Instead of hCG levels, an ultrasound is a more accurate indicator of a healthy pregnancy once you reach the 5- to 6-week mark. Measuring hCG Levels Urine tests detect the presence of hCG but not the amount. Blood tests can be either qualitative (meaning they determine if hCG is in your blood) or quantitative (determining exactly how much hCG is in your blood). Your doctor may want to check your hCG level in early pregnancy if you experience symptoms of a miscarriage, such as bleeding and cramping. Slow-rising hCG levels can also be a sign of an ectopic pregnancy. If your hCG level is high enough, ultrasounds can be used to detect a gestational sac and monitor fetal development. Patterns of hCG in Early Pregnancy Everyone is different, and hCG levels can fluctuate without indicating a larger issue. For instance, a study that monitored hCG patterns in healthy pregnancies found that the lowest documented two-day hCG increase was just 53%. This means an hCG level increase of about 75% (rather than by 100%, which is doubling) after three days could still be normal. If your hCG levels aren't exactly doubling but are still increasing, that's a good sign. Because of these natural variations, hCG patterns alone cannot determine whether or not your pregnancy is viable. Hormone testing should always be followed up by an ultrasound before a diagnosis is made. In the early weeks of pregnancy, hCG levels that decrease are more likely to indicate a miscarriage than those that increase at a slower rate. The hCG level tends to peak between weeks 8 and 11 of gestation. Once you enter the second trimester, hCG will level off and decline closer to the level it was back when you were just 6 to 8 weeks pregnant. A Word From Verywell Although it's tempting to read into every detail during the first few weeks of pregnancy, it's best to try and be patient for your first ultrasound appointment. Increases in hCG are expected for a viable pregnancy, but this information must be viewed within the context of additional tests, signs, and symptoms. Your doctor can help you decide which tests are best for you based on your individual medical history and concerns. Was this page helpful? Thanks for your feedback! Get diet and wellness tips delivered to your inbox. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Craig Medical Distribution INC. Chart of hCG hormone ranges during human pregnancy. Whitworth M, Bricker L, Neilson JP, Dowswell T. Ultrasound for fetal assessment in early pregnancy. Cochrane Database Syst Rev. 2010;(4):CD007058. doi:10.1002/14651858.CD007058.pub2 Seeber BE. What serial hCG can tell you, and cannot tell you, about an early pregnancy. Fertil Steril. 2012;98(5):1074-7. doi:10.1016/j.fertnstert.2012.09.014 American Pregnancy Association. What is HCG?. Updated April 25, 2017.