[Antenatal exposure to corticosteroids for fetal lung maturation and its repercussion on weight, length and head circumference in the newborn infant]. / Exposición prenatal a glucocorticoides para acelerar la maduración pulmonar fetal y su repercusión sobre el peso, la talla y el perímetro cefálico del recién nacido.

BACKGROUND AND OBJECTIVE: To study the effects of antenatal corticosteroids treatment to promote fetal lung maturation, on fetal growth, depending on the number of the courses administered. PATIENTS AND METHOD: The study was based on data from the Spanish Collaborative Study of Congenital Malformations (ECEMC), analysing a sample of 29,557 singleton liveborn infants without congenital defects. An stratified analysis by gestational age was performed to compare the weight, length and head circumference at birth, in the exposed and unexposed infants to dexamethasone/betamethasone. To control confounding factors (year of birth, maternal age, gestational age, parity, maternal smoking and/or alcohol consumption, gestational diabetes, non-gestational diabetes and other maternal chronic diseases) we used a general linear model with random effects, being the randomised variable the place of birth. RESULTS: The exposure to more than one course of antenatal corticosteroids resulted in a significant reduction of birth weight, length and head circumference in singleton preterm infants. The birth weight decreased by 22% (p < 0.0001), the length 5% (p = 0.002) and the head circumference 6% (p = 0.0005). The treatment with only one course reduced also significantly the weight and length but not the head circumference. In addition, we observed a significant interaction between the treatment and gestational age at birth indicating that the effect of corticosteroids is stronger in the most premature babies. CONCLUSIONS: In this retrospective analysis, the antenatal exposure to corticosteroids to promote fetal maturation is associated with diminished weight, length and head circumference in the premature newborn infant. This negative effect was greater in those premature babies exposed to multiple courses.

[Secular evolution and evolution according to autonomous communities of the frequency of fertility treatments, multiple deliveries and cesarean sections in Spain]. / Evolución secular y por autonomías de la frecuencia de tratamientos de fertilidad, partos múltiples y cesáreas en España.

BACKGROUND AND OBJECTIVE: Fertility treatments, multiple deliveries and caesarean sections are related to maternal age. Because maternal age has increased in Spain, it can also be expected an increase in these variables. We analyzed their evolution over the time and by maternal age, either globally and by Spanish Autonomous Communities. SUBJECTS AND METHOD: We studied a sample of 30,956 mothers of non-malformed newborn infants from all over Spain. STUDY PERIOD: between 1977 and June 2002. RESULTS: The percentage of fertility treatments shows a statistically significant increasing trend in all of the maternal ages groups. However, this was higher in mothers older than 34 years, among whom the frequency of multiple deliveries also increased (p = 0.01). The same trends were observed by Spanish Autonomous Communities, yet with differences between them. In the Comunidad Valenciana, we identified the highest frequency of fertility treatments, while the highest mean maternal age was observed in Aragón. Galicia has one of the lowest proportions of multiple deliveries, while the percentage of fertility treatments is similar to other regions. The percentage of caesarean sections (over 25%, globally) shows a statistically significant increasing trend in all the maternal ages groups, the highest one being among mothers older than 39 years. CONCLUSIONS: The observed increasing maternal age implies a higher use of fertility treatments, multiple deliveries and caesarean sections. All these variables show statistically significant variations between Spanish Autonomous Communities and over the time.