Table 2.
Risk of selected complications and adverse outcomes after IVF vs. SC pregnanciesa
| Complication/ outcome | IVF | SC | Crude RR (95% CI) | RR (95% CI) adjusted for: | ||
|---|---|---|---|---|---|---|
| Maternal age | + Study period | + Ethnicity, education, marital status | ||||
| Pregnancy-related complications b | 650 | 8206 | 1.49 (1.40–1.59) | 1.28 (1.19–1.36) | 1.28 (1.20–1.37) | 1.28 (1.19–1.36) |
| Pre-eclampsia | 78 | 1007 | 1.46 (1.17–1.83) | 1.24 (0.97–1.57) | 1.25 (0.98–1.59) | 1.25 (0.98–1.59) |
| Placental complicationsc | 49 | 299 | 3.09 (2.30–4.17) | 2.71 (1.96–3.76) | 2.74 (1.98–3.79) | 2.74 (1.97–3.79) |
| Placenta previa | 22 | 51 | 8.14 (4.95–13.39) | 7.51 (4.27–13.23) | 7.57 (4.29–13.35) | 7.15 (4.04–12.66) |
| Placental abruption | 32 | 250 | 2.42 (1.68–3.48) | 2.08 (1.40–3.07) | 2.10 (1.42–3.10) | 2.12 (1.43–3.14) |
| Cesarean sectiond | 620 | 7715 | 1.52 (1.42–1.62) | 1.28 (1.20–1.37) | 1.29 (1.20–1.38) | 1.28 (1.20–1.37) |
| Planned | 217 | 1698 | 2.41 (2.11–2.75) | 1.89 (1.64–2.17) | 1.92 (1.67–2.21) | 1.92 (1.67–2.21) |
| Emergency | 403 | 6017 | 1.26 (1.16–1.38) | 1.09 (1.00–1.20) | 1.10 (1.00–1.20) | 1.09 (0.99–1.19) |
| Adverse pregnancy outcomes e | 400 | 5720 | 1.32 (1.21–1.44) | 1.18 (1.07–1.29) | 1.18 (1.07–1.29) | 1.17 (1.07–1.29) |
| Preterm birth (< 37 weeks) | 153 | 1668 | 1.73 (1.48–2.01) | 1.49 (1.26–1.76) | 1.49 (1.26–1.76) | 1.51 (1.28–1.78) |
| Spontaneous preterm birth | 48 | 616 | 1.47 (1.10–1.96) | 1.30 (0.95–1.77) | 1.30 (0.95–1.77) | 1.32 (0.97–1.80) |
| Iatrogenic preterm birth | 105 | 1052 | 1.88 (1.55–2.29) | 1.60 (1.31–1.96) | 1.61 (1.31–1.97) | 1.62 (1.32–1.98) |
| Very preterm birth (< 32 weeks) | 30 | 300 | 2.10 (1.44–3.05) | 1.47 (0.99–2.18) | 1.48 (0.99–2.20) | 1.49 (1.00–2.23) |
| Low birthweight (< 2500 g) | 109 | 1146 | 1.80 (1.48–2.17) | 1.46 (1.19–1.78)f | 1.46 (1.20–1.78)f | 1.47 (1.20–1.80)f |
| Very low birthweight (< 1500 g) | 22 | 241 | 1.90 (1.23–2.93) | 1.32 (0.84–2.06)f | 1.31 (0.84–2.05)f | 1.31 (0.84–2.06)f |
| Small for gestational age | 46 | 613 | 1.42 (1.05–1.90) | 1.23 (0.91–1.67) | 1.23 (0.91–1.67) | 1.23 (0.91–1.66) |
| Apgar score at 5 min < 7 | 30 | 401 | 1.41 (0.98–2.04) | 1.20 (0.81–1.77) | 1.22 (0.82–1.80) | 1.20 (0.81–1.77) |
| Congenital anomalies | 40 | 506 | 1.49 (1.09–2.05) | 1.50 (1.08–2.09) | 1.52 (1.09–2.12) | 1.51 (1.08–2.11) |
| Admission to a NICU | 300 | 4369 | 1.30 (1.16–1.44) | 1.14 (1.02–1.27) | 1.13 (1.02–1.27) | 1.13 (1.01–1.26) |
aLiveborn singletons to primiparas in Estonia, 2005–2014
bAt least one of the following complications: pre-eclampsia, placenta previa, placental abruption, cesarean section
cPlacenta previa or placental abruption
dPlanned or emergency cesarean section
eAt least one of the following outcomes: preterm birth, low birthweight, small for gestational age, Apgar score at 5 min < 7, congenital anomalies, admission to a NICU
fAdditionally adjusted for infant’s sex
CI Confidence interval, IVF In vitro fertilization, NICU Neonatal intensive care unit, RR Relative risk (prevalence proportion ratio), SC spontaneously conceived