Merry Little and colleagues assessed the perinatal health of infants born of mothers who were homeless or underhoused or had substance abuse. Compared to women without these problems women who were underhoused or homeless were 2.9 times more likely to have a pre-term delivery, 6.9 times more likely to give birth to an infant who weighed less than 2000 grams and 3.3 times more likely to have a newborn small for gestational age, even after adjustment for (taking into account) known risks factors such a age of the mother, number of previous pregnancies and tobacco smoking.
Pregnant women who are underhoused, homeless or suffer from substance abuse are at very high risk for having an adverse perinatal outcome that compromises the health of their infant.
Adverse perinatal outcomes associated with homelessness and substance use in pregnancy
-- Dr. M. Little et al.
http://www.cmaj.ca/misc/press/pg615.pdf
Canadian Medical Association Journal