Table 4.

Analysis of fetal events

EventDenominatorFixed-Effects AnalysisRandom-Effects Analysis
Test for HeterogeneityEstimated Rate (95% CI)Estimated Rate (95% CI)SD Estimatea
Induced abortionsNumber of pregnancies<0.0017.2% (6.0%, 8.4%)5.9% (3.2%, 8.6%)5.6%
Spontaneous abortionsNumber of pregnancies without induced abortions<0.00116.6% (14.7%, 18.5%)16.0% (12.1%, 19.9%)7.6%
StillbirthsNumber of pregnancies without induced abortions0.0014.0% (2.9%, 5.1%)3.6% (2.0%, 5.2%)2.2%
Neonatal deathsNumber of pregnancies without induced abortions0.0502.8% (1.9%, 3.8%)2.5% (1.2%, 3.8%)1.5%
Unsuccessful pregnanciesNumber of pregnancies without induced abortions0.02523.0% (20.3%, 25.6%)23.4% (19.5%, 27.3%)4.7%
Intra Uterine Growth Retardation (IUGR)Number of pregnancies without induced abortions<0.00114.3% (12.4%, 16.2%)12.7% (8.8%, 16.7%)6.8%
Premature Birth RateNumber of live births<0.00137.1% (34.8%, 39.4%)39.4% (32.4%, 46.4%)17.6%
  • a To compute an estimate of the random-effects SD, which depends on the value of the complication rate, the central value from the random-effects model (i.e., the random-effects estimated rate) was used in the calculation.