Oh, that's why there are no Russians, Ukrainians, or Poles on my street! Oh, wait a minute ...
My anecdotal sample suggests that getting out of their home country makes Eastern Europeans more likely to have children. All the families I know are larger than average, and the Ukrainian Evangelicals are the only people in the neighborhood with as many children as my family. Perhaps what native-born Americans consider "way too poor to have children" looks really good, compared to Ukraine.
That trend is evident in Mexican immigrants here. The TFR in Mexico around 2.3, but for Mexican Americans the TFR of 2.99 per 2008 data.
I live in King County, WA, straight east of Seattle.
We have so many Russians here that the Bellevue Social Service office has telephone assistance in Russian, but NOT in Spanish!