[Out-of-hospital births in Germany--a comparison of "large", "medium", and "small" free-standing birth centres]

How do maternal and foetal outcomes in out-of-hospital births vary in relation to birth centre size?

Routine perinatal data from out-of-hospital births in 80 birth centres in Germany between 1999 and 2002 were analysed. Birth centres were grouped according to their annual mean birth rate into small (< or = 70 births per year), medium (71 - 155 births per year), and large (> 155 births per year) units. Breech births (n = 43) and twins (n = 14) were excluded from the analysis (level of significance p < 0.01).

Pregnancy and perinatal risks, foetal and maternal morbidity and mortality, perineal lacerations and transfer of newborns to NICU did not differ between the three groups which comprised a total of 14,629 births. Less episotomies were performed in large birth centres compared to small or medium-sized birth centres. Significantly less women were transferred from medium-sized birth centres to hospital following delivery. Five minute Apgar scores < or = 7 were significantly more frequent in birth centres with the highest birth rates. During labour significantly less women were transferred to hospital from medium-sized birth centres than from small or large centres. The transfer rate difference between nulliparae and multiparae was 4 : 1.

Perinatal parameters appear to differ in some aspects according to how the birth centres were labelled. Nevertheless, these differences have only little clinical significance and may be explained by the demographic characteristics of the population. These results do not allow the general conclusion that the quality of out-of-hospital care in Germany differs in relation to the annual birth rates of the birth centres.