Compared

Each comparison names its basis first, and every figure links to the page it came from.

Is a U-shaped pillow better than a straight one?

Only if you turn over often. A straight 20 by 54 inch pillow gives the same knee and arm support in far less of the bed.

A wide U such as Regalo's runs 30 inches across (Regalo), which is half of a 60-inch queen (Avocado mattress size guide). A U supports both sides without being moved, so it suits people who switch sides often. The full comparison is in is a U-shaped body pillow worth it.

Is a wedge enough in pregnancy?

For belly support alone, often yes. It does nothing between the knees or behind the back.

ACOG suggests a pillow between the knees and another under the belly, or a full-length body pillow (ACOG). No pillow shape has been shown to keep you off your back: in a 2025 crossover trial, time on the back was 13.0% of sleep with people's own pillows and 16.0% with a pillow built to prevent it (Wilson et al., BJOG). See is a pregnancy wedge pillow enough.

Weighted or memory foam?

Weight gives pressure to hug, and foam holds the knees apart. No trial has tested a weighted body pillow.

The evidence sellers cite comes from weighted blanket trials, at a dose no pillow reaches. For keeping the top knee level, our judgement is that a firm full-length foam pillow does more than a narrow weighted tube. The figures are in weighted or memory foam body pillow.

Does a cooling cover beat an ordinary one?

At first touch, yes. Over a night, cooling fabric warms toward skin temperature, and only 2 of 9 listings read gave any cooling figure.

A review of nine studies found that cooling mattresses and toppers did not change measured sleep stages (Frontiers in Sleep). The room does more of the work. See does a cooling body pillow keep you cool all night.