Betamethasone Fetal Lung Maturity Timing

Antenatal corticosteroids for preterm birth <34 weeks: Betamethasone 12 mg IM × 2 doses, 24 hours apart (or dexamethasone 6 mg IM q12h × 4 doses). Benefit window: 24–34 weeks (strongest evidence); consider at 22–23 weeks for periviable infants. Peak effect: 48 hours–7 days after first dose. Reduces RDS, IVH, NEC, and neonatal mortality by ~40%.

Weight
Height
Clinical Guidance

BMI is a screening measure of body size, not a direct measure of body fat. The standard WHO categories are underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30).

BMI can overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Interpret it alongside waist circumference and clinical context rather than as a standalone diagnosis.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.
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How to Use

Enter the values for the scenario you are assessing. Antenatal corticosteroids for preterm birth <34 weeks: Betamethasone 12 mg IM × 2 doses, 24 hours apart (or dexamethasone 6 mg IM q12h × 4 doses). Benefit window: 24–34 weeks (strongest evidence); consider at 22–23 weeks for periviable infants. Peak effect: 48 hours–7 days after first dose. Reduces RDS, IVH, NEC, and neonatal mortality by ~40%. Use the betamethasone timing result to inform your calculation.

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