Neonatal Outcomes in the Birth Center Setting: A Systematic Review.

Introduction: This systematic review investigates the effect of the birth center setting on neonatal mortality in economically developed countries to aid women and clinicians in decision making.

Methods: We searched the Google Scholar, CINAHL, and PubMed databases using key terms birth/birthing center or out of hospital with perinatal/neonatal outcomes. Ancestry searches identified additional studies, and an alert was set for new publications. We included primary source studies in English, published after 1980, conducted in a developed country, and researching planned birth in centers with guidelines similar to American Association of Birth Centers standards. After initial review, we conducted a preliminary analysis, assessing which measures of neonatal health, morbidity, and mortality were included across studies.

Results: Neonatal mortality was selected as the sole summary measure as other measures were sporadically reported or inconsistently defined. Seventeen studies were included, representing at least 84,500 women admitted to a birth center in labor. There were substantial differences of study design, sampling techniques, and definitions of neonatal outcomes across studies, limiting conclusive statements of the effect of intrapartum care in a birth center. No reviewed study found a statistically increased rate of neonatal mortality in birth centers compared to low-risk women giving birth in hospitals, nor did data suggest a trend toward higher neonatal mortality in birth centers. As in all birth settings, nulliparous women, women aged greater than 35 years, and women with pregnancies of more than 42 weeks' gestation may have an increased risk of neonatal mortality.

Discussion: There are substantial flaws in the literature concerning the effect of birth center care on neonatal outcomes. More research is needed on subgroups at risk of poor outcomes in the birth center environment. To expedite research, consistent use of national and international definitions of perinatal and neonatal mortality within data registries and greater detail on adverse outcomes would be beneficial.