Quick answer

Cloth diaper leaks usually come down to fit, absorbency, or compression. Check the leg gussets for gaps, add absorbency for heavy wetters, and ensure you're using the right insert material for your baby's output.

Common Leak Causes and Fixes

Fit issues are the most common culprit. If the diaper is too loose around the legs or waist, urine or poop can escape before the fabric absorbs it. Make sure the leg gussets sit snugly against the skin without leaving red marks. For newborns, a dedicated newborn size like the Thirsties Natural Newborn All-in-One (fits 5–14 pounds) provides a much better seal than a one-size diaper that hasn't been adjusted properly.

Absorbency problems show up as leaks through the fabric itself. If the diaper feels heavy and wet all the way through, you need more absorbent material or a different fiber. Cotton and hemp hold more liquid than microfiber and are less prone to compression leaks. For heavy wetters, consider adding a hemp booster or switching to a prefold setup like the Cloth-eez Prefolds found in the Hello Small Baby Kit.

Compression leaks happen when pressure forces liquid out of the insert—common when baby sits in a car seat or carrier. Synthetic materials like microfiber are especially prone to this. Using natural fibers (cotton, hemp) or pairing a microfiber insert with a natural fiber topper can solve the problem.

Leak Diagnosis Guide

  • Leak at the legs or waist: Check for gaps. The diaper should fit snugly without leaving marks. Adjust snaps or hook-and-loop tabs. If using a one-size diaper on a newborn, try a newborn-specific size. If gaps remain, try a different diaper style or size.
  • Leak through the fabric (soggy diaper): The diaper is saturated. Add a booster or switch to a more absorbent material like hemp or cotton. For heavy wetters, try a prefold or fitted diaper under a cover. If leaks persist, consider a nighttime diaper with extra layers.
  • Leak only after sitting or pressure: Compression leak. Replace microfiber inserts with natural fibers (cotton, hemp) or add a natural fiber topper. Avoid overstuffing pockets. If still leaking, the diaper may need stripping of detergent buildup.

Products That Help Prevent Leaks

  • Thirsties Natural Newborn All-in-One - Snap (for newborns): Thirsties Natural Newborn All-in-One is made of organic cotton and hemp, sized for newborns 5–14 pounds. It's an all-in-one diaper with the waterproof outer sewn together with the absorbent part. A proper newborn fit eliminates leg gaps that cause leaks, and the cotton-hemp blend provides reliable absorbency without compression issues.
  • Hello Small Baby Kit: Hello Small Baby Kit includes 2 dozen Cloth-eez Prefolds (size small, fits 10–15 pounds) and 2 dozen birdseye wipes, plus a how-to booklet. Prefolds offer customizable absorbency—you can fold them to add layers where baby needs them most, making it easier to fix absorbency issues as your baby grows.