Beta HCG Calculator
Calculate HCG doubling time and assess early IVF pregnancy viability
Last updated: December 2024
First Beta HCG Test
Typically tested 9-14 days post transfer
Second Beta HCG Test
Usually 48-72 hours after first test
Common Questions
What is a normal HCG doubling time?
For HCG levels below 1200 mIU/mL, doubling time should be 48-72 hours. Between 1200-6000 mIU/mL, it doubles every 72-96 hours. Above 6000 mIU/mL, doubling slows to 96+ hours. Peak levels occur at 8-11 weeks, then gradually decline.
Can a pregnancy be viable with slow doubling?
Yes, some viable pregnancies have slower HCG rise. Single values are less important than the overall trend. Factors like vanishing twin, later implantation, or individual variation can affect doubling time. Only ultrasound can confirm viability definitively.
What HCG level is normal after IVF transfer?
For Day 5 transfer: 9dp5dt (14 DPO): 50-200 mIU/mL; 11dp5dt (16 DPO): 100-400 mIU/mL; 14dp5dt (19 DPO): 300-1000 mIU/mL. Twin pregnancies typically have higher levels. Wide variation is normal; doubling rate matters more than single values.
When should I be concerned?
Concerning signs include: doubling time over 96 hours in early pregnancy, plateauing or declining HCG, levels below 50 at 14 DPO, severe cramping or bleeding, or one-sided pain (ectopic risk). Contact your fertility clinic immediately with any of these symptoms.