What is the normal hCG level at 4 weeks of pregnancy?

At four weeks of gestation—calculated from the first day of the woman’s last menstrual period (LMP)—the serum human chorionic gonadotropin (hCG) level typically ranges from approximately 5 to 426 mIU/mL. This wide range reflects normal biological variability among individuals and depends on factors such as implantation timing, embryo viability, and assay methodology. It is important to note that hCG levels usually double every 48–72 hours in early viable pregnancies; therefore, a single measurement is less informative than serial measurements when assessing pregnancy health. Clinicians often rely on transvaginal ultrasound in conjunction with quantitative hCG testing after 5–6 weeks’ gestation to confirm intrauterine pregnancy and rule out ectopic or nonviable gestations.

A value below 5 mIU/mL generally indicates absence of pregnancy, while levels above 2,000 mIU/mL at this stage may raise concern for multiple gestation or molar pregnancy—but these interpretations require clinical correlation and further evaluation. Because hCG kinetics—not absolute values—are more predictive of pregnancy outcomes, repeat testing 48–72 hours later is standard practice if initial results are inconclusive or discordant with clinical findings.