Timing of enhanced prenatal care and birth outcomes in New Jersey's HealthStart program

This study examined the effects of prenatal care and the timing of its initiation on birth weight and gestational age outcomes among women in a state-wide Medicaid enhanced prenatal care program.

Ordinary Least Squares and logistic regression analyses were performed using data on 88,196 births in New Jersey between 1988 and 1996. A large number of potentially confounding factors were included.

Initiating prenatal care in the first trimester was associated with a 56 g advantage in birth weight (p = .01) compared to no care. Initiating prenatal care in the first or second trimester was associated with a 1 day advantage in gestational age (p = .05). There were no significant effects of prenatal care, initiated in any trimester, on low-birth weight. Initiating care in the first versus the second trimester had no effect on the probability of delivering preterm. The findings did not vary by sociodemographic subgroup.

This study provides support for claims that there is little that prenatal care can do to improve aggregate birth outcomes because most pregnancy complications are the result of behaviors and life circumstances that precede the pregnancy and are very difficult to reverse. Prenatal care, even with enhanced services, appears to offer too little, too late.