Previous studies have concluded that IUGR increased mortality, and male gender increased BPD incidence in <1500 grams. We hypothesized that maternal betamethasone is beneficial even in IUGR infants with regards to mortality, and infants of both sexes from BPD. Data were collected on 36 pairs of twins born between 1993 and 1994, inclusive. The mean birthweight (B.W.) was 1359±202 (±SD) grams (gm) and the mean gestational age (GA) was 30.3±1.7 wks. The male/female ratio was 11:23. Six (6) infants were IUGR, one was LGA, and 65 were AGA. All 6 IUGR infants were from different sets of twins. Results: There were 11 male:male twins, 19 female:female twins and 6 pairs with discordant for sex (female: male or male:female, for the birth order). The mean BW and GA for males was 1382±201gms and 30.3±1.9 wks and for females was 1337±181and 30.3±1.7 wks respectively. The incidence of BPD in Twin A was 19.4% vs 27.8% in Twin B (ns) and an incidence of IVH in Twin A of 11.1% vs 8.3% in Twin B (ns). Table shows other results. (IVH= intraventricular hemorrhage, Mat-B=maternal betamethasone).

Table 1
Full size table

The female vs male frequencies for IVH was 13.6% vs 3.6 (p<0.01), and for BPD was 27.3% vs 17.8%(ns). The effect of birth order was not significant. Summary and conclusions: From our data, all morbidities except IVH remained equal. We could not demonstrate higher morbidity in males. This could be a beneficial effect on males due to betamethasone. The mortality from the IUGR group was zero, the only death was in an AGA infant. Male gender show a larger size for gestational age than females did, however, did not have an effect on the BPD incidence. The birth order, as expected, did not show any significance with the incidences of either IVH and BPD.