# Average class number formula for imaginary quadratic fields with prime discriminant

For a positive integer $d$, let $h(-d)$ denote the class number of the imaginary quadratic field $\mathbb{Q}(\sqrt{-d})$. Is there a known asymptotic formula for the sum

$$\displaystyle \sum_{\substack{p \leq x \\ p \equiv 3 \pmod{4}}} h(-p)?$$

It seems to me one should be able to derive such a formula from the class number formula and the known statistical results on $L(1,\chi)$. But... I see now this has already been worked out. See
According to the MathSciNet review, the author gets asymptotic formulas for all the (positive integral) moments of $h(-p)$, for $p \equiv 3\pmod{4}$.