Association between stressful life events during pregnancy and low birth weight, Puerto Rico, 1999-2000

Low birth weight (LBW) is the principal cause of fetal and neonatal morbidity and mortality, and has been associated with the development of certain chronic diseases later in life. Recent studies suggest that stressful life events (SLE) experienced by the mother during pregnancy are potential risk factors for premature and LBW babies, but this association has not been evaluated in Puerto Rico. This study evaluates the association between having experienced SLE during pregnancy and LBW of the neonates born in Puerto Rico between July 1999 and May 2000. This is a secondary data analysis of a matched case-control study entitled "Risk Factors Associated with Low Birth Weight in Puerto Rico". The population under study is a probabilistic sample representative of the mothers who gave birth from July 1999 thru May 2000 in one of 28 hospitals randomly selected from the 6 health regions in Puerto Rico. Babies whose birth weight was below 5.5 pounds were defined as cases (n=718); those whose weight was above 5.5 pounds were defined as controls (n=718). Mothers of LBW babies reported having experienced more SLE overall compared to mothers whose babies weighted more than 5.5 pounds. After classifying stressful life events as emotional, financial, partner-associated and traumatic, mothers who experienced traumatic stressors during pregnancy have a significantly higher probability of having a LBW baby (OR: 1.464, CI 95%: [1.142-1.877], p-value: 0.003) compared to mothers who did not experienced this kind of stressor. Screening for SLE have to be incorporated in the prenatal care protocol.