Objective: To measure the use of infertility treatments in the general
population and their association with neonatal health. Design: Cross-
sectional, population-based study. Setting: Canton of Vaud, Switzerlan
d; Etude du Developpement des Nouveau-nes (EDEN), a prospective study
of chronic childhood conditions. Patient(s): Six thousand four hundred
seventy-seven live newborns(6,379 pregnancies) delivered of residents
of Vaud in the 19 maternity hospitals between 1993 and 1994. Main Out
come Measure(s): Neonatal morbidity, multiplicity, low birth weight, p
rematurity, intrauterine growth retardation, transfer to intensive car
e, and length of hospital stay. Result(s): Infertility treatments were
reported for 2.1% of pregnancies (129 women, 148 newborns) and were a
ssociated significantly with adverse outcomes. Population-attributable
risks varied from 3%-20%. The outcomes of twins did not differ regard
less of whether their mother was treated for infertility. Among single
tons, only low birth weight was significantly more frequent when infer
tility treatments were used. Unadjusted odds ratios for neonatal morbi
dity were significant only for multiple births (2.56; 95% confidence i
nterval 1.21-5.42). This association was not influenced by maternal ch
aracteristics and it disappeared after controlling for sex, gestationa
l age, and birth weight. Conclusion(s): An independent effect of infer
tility treatments on neonatal morbidity cannot be ruled out, but most
of their impact appeared to be mediated by multiplicity and prematurit
y. Reducing the number of medically induced multiple pregnancies is th
e most effective prevention of neonatal morbidity related to infertili
ty treatments. Follow-up studies are needed. (C) 1998 by American Soci
ety for Reproductive Medicine.