Figure 2. The effects of antenatal betamethasone on both spontaneous and indomethacin-induced ductus constriction at 7 days after birth.

Bars represent the incidence of moderate-to-large PDA that persist beyond 7 days. Open bars = Conservative era; Dark bars = Prophylactic indomethacin era. The top panel shows the effects of betamethasone at each gestational week: ≤24^6/7, 25^0/7-25^6/7, 26^0/7-26^6/7, and 27^0/7-27^6/7 weeks. Statistical analyses were performed on the two gestational age groups presented in the bottom panel (≤25^6/7) and (26^0/7-27^6/7).

BMZ+, “Adequate BMZ exposure” see Methods for definition. N, number of infants examined by echocardiogram at 7 days. *, p<0.05; NS, not significant.