Early pregnancy loss and obstetrical risk after in-vitro fertilization and embryo replacement.

Between March 1983 and March 1986, 108 pregnancies were obtained at the IVF clinic of St Pierre Hospital in Brussels. There were 29 chemical pregnancies (26.8%), five ectopic pregnancies (4.6%), 15 abortions (14%) and 59 ongoing pregnancies of over 20 weeks (54%). Patients who had experienced a chemical pregnancy at first trial displayed a significantly higher rate of ongoing pregnancy at their second attempt. Among the 15 cases of abortion, a chromosomal anomaly was detected in two cases and suspected in a third. Four of the five ectopic pregnancies occurred in patients with previously documented tubal pathology. The ongoing pregnancies were distributed as 44 singletons, 13 pairs of twins, one set of triplets and one set of quadruplets. The Caesarian section rates were 21 and 40% for single and multiple pregnancies, respectively. The prematurity rate was low for singletons (4.5%) but reached 46.6% in multiple pregnancies. Two minor malformations were observed and five perinatal deaths occurred; among these latter, four cases were twins. It appears that perinatal pathology is substantially higher among IVF pregnancies than in the normal population. It is clear, however, that most of this difference is accounted for by the considerably higher rate of twin pregnancy displayed by the former group.