Triplets and Higher-Order Multiple Births

Population based study of rates of multiple pregnancies in denmark, 1980-94

“…The existence in Denmark of such complete national registers enabled us to study trends in rates of multiple pregnancy that were adjusted for such confounding effects. This is in contrast with previous studies that have either lacked this possibility or have only to some extent been able to distinguish between these factors 1 9 10 11. In the Netherlands a 1.3-fold increase was reported in the twinning rate and a 2.7-fold increase in the triplet rate from 1975 to 1989.…”

“…In white Americans in the United States there was a 1.3-fold increase in the ratio of twins among liveborn children from 1980 to 1992 10. In the same population a 2.1-fold increase was reported in the rate of triplet and higher order multiple births from 1972-4 to 1985-9, which, adjusted for maternal age, amounted to a 1.8-fold increase, an increase that was seen particularly in women ≥30 years of age 11. The impact of parity on the increasing rates in the United States, however, could not be determined in either of these studies 10 11…”

Ovarian stimulation and intrauterine insemination at the quarter centennial: implications for the multiple births epidemic

“…The corresponding figures for the twin birth rate were 12%-14% (16). As such, these observations are in general agreement with a body of earlier work (19)(20)(21)(22) dating back to 1971. Any remaining components of the national multiple birth rate must be viewed as iatrogenic and attributable to one or more fertility-promoting interventions (13), such as OS/IUI, ovulation induction (OI), IVF, and egg donation.…”

Illness severity measured by CRIB score: a product of changes in perinatal care?

“…The nearly fourfold increase in the rate of multiple pregnancies is unlikely to be explained wholly by an increased readiness to deliver babies before 31 weeks of gestation; the finding therefore confirms the impact of assisted fertility treatments on the population of very low birthweight babies and on the neonatal service 1516Although multiple birth had no significant effect on postnatal CRIB score or survival, firstborn babies had significantly lower postnatal CRIB scores, perhaps reflecting greater pulmonary maturity and reduced intrapartum asphyxia.…”