Table 2 Pregnancy outcomes (ITT)

From: IVF versus ICSI in patients without severe male factor infertility: a randomized clinical trial

Parameters

ICSI (n = 414)

c-IVF (n = 408)

Risk difference (95% CI)

Risk ratio (95% CI)

P valuea

Primary outcome

 CLBR

179/414 (43.2%)

193/408 (47.3%)

−0.04 (−0.11 to 0.03)

0.91 (0.79–1.06)

0.24

 Missing data

0

0

–

–

–

Secondary outcomes

 Participants with more than one live birthb

7/414 (1.7%)

16/408 (3.9%)

−0.02 (−0.05 to 0.00)

0.43 (0.17–1.00)

0.06

Outcomes following first embryo transferc

 Embryo transfers

327/414 (79.0%)

341/408 (83.6%)

−0.46 (−0.10 to 0.01)

0.95 (0.88–1.01)

0.09

 Fresh, n (%)

243/327 (74.3%)

253/341 (74.2%)

–

–

–

 FET, n (%)

84/327 (25.7%)

88/341 (25.8%)

–

–

–

 Participants with no embryo transfer

87/414 (21.0%)

67/414 (16.4%)

0.46 (−0.01 to 0.10)

1.28 (0.96–1.71)

0.09

 Positive s-hCG rate

176/414 (42.5%)

187/408 (45.8%)

−0.03 (−0.10 to 0.03)

0.93 (0.79–1.08)

0.34

 Fresh transfer

126/243 (51.9%)

132/253 (52.2%)

–

–

–

 FET

50/84 (59.5%)

55/88 (62.5%)

–

–

–

 Missing data

0

0

–

–

–

 Implantation rated

139/327 (42.5%)

152/341 (44.6%)

−0.04 (−0.10 to 0.03)

0.90 (0.75–1.08)

0.27

 Fresh transfer

96/243 (39.5%)

104/253 (41.1%)

–

–

–

 FET

43/84 (51.2%)

48/88 (54.5%)

–

–

–

 Missing data

0

0

–

–

–

 Ongoing pregnancy rate

120e/414 (29.0%)

132f/408 (32.4%)

−0.03 (−0.10 to 0.03)

0.90 (0.73–1.10)

0.3

 Fresh transfer

83e/244 (34.0%)

91f/255 (35.7%)

–

–

–

 FET

37/84 (44.0%)

41/88 (46.6%)

–

–

–

 Missing data

0

0

–

–

–

 Live birth rate

110e/414 (26.6%)

129f/408 (31.6%)

−0.05 (−0.11 to 0.01)

0.84 (0.68–1.04)

0.11

 Fresh transfer

77e/244 (31.6%)

89f/255 (34.9%)

–

–

–

 FET

33/84 (39.3%)

40/88 (45.5%)

–

–

–

 Missing data

0

0

–

–

–

 Pregnancy loss

24/414 (5.8%)

21/408 (5.1%)

6.50 × 10−3 (−0.03 to 0.04)

1.13 (0.64–2.01)

0.68

 Early pregnancy lossg

23/414 (5.6%)

21/408 (5.1%)

40.8 × 10−3 (−0.03 to 0.04)

1.08 (0.61–1.93)

0.79

 Late pregnancy lossh

1/414 (0.2%)

0

–

–

–

 Elective abortion

4/414 (1.0%)

0

–

–

–

 Anembryonic pregnancyi

33/414 (8.0%)

30/408 (7.4%)

6.18 × 10−3 (−0.03 to 0.04)

1.08 (0.67–1.75)

0.74

 Ectopic pregnancy

4/414 (1.0%)

5/408 (1.2%)

−2.59 × 10−3 (−0.02 to 0.01)

0.79 (0.2–2.96)

0.72

 Stillborn

0

1 (0.2%)

–

–

–

 Twin pregnancy

1/414 (0.2%)

1/408 (0.2%)

0 (−0.01 to 0.01)

0.99 (0.04–24.87)

0.99

 Twin delivery

0

1/408 (0.2%)

–

–

–

Time to pregnancy from inclusion date (d)

 Time to 25% of population achieved live birthj

331

320

–

–

–

 Time to viable pregnancy leading to live birth, median (IQR)

90 (42–158)

93 (43–127)

–

–

0.82

  1. CLBR is defined as at least one live birth resulting from an ART cycle, including the initial fresh embryo transfer and all subsequent FETs from that cycle. The follow-up period was 12 months after the inclusion of the last participant (14 December 2023), encompassing all embryos transferred within this timeframe, as well as one spontaneous pregnancy in the ICSI group and two in the c-IVF group.
  2. aThe P values for binary variables were calculated using a Wald test, with effect estimates (β) and s.e. derived from a generalized linear model. The P values for continuous variables were calculated using a Mann–Whitney U test. All tests were two sided.
  3. bParticipants who experienced two live birth episodes (twins not included) resulting from separate embryo transfers using embryos derived from the study cycle, occurring within the 12-month follow-up period after inclusion of the last participant.
  4. cFirst transfer outcomes were not prespecified in the study protocol.
  5. dImplantation rate was calculated using all participants who had a positive s-hCG after the first transfer, excluding those with an ectopic pregnancy or an anembryonic pregnancy, as the numerator (ultrasound scans were not routinely performed before GA week 7) and the total number of embryos transferred in the first transfer as the denominator.
  6. ePlus one additional spontaneous pregnancy.
  7. fPlus two additional spontaneous pregnancies.
  8. g<GA12, including blighted ovum.
  9. hGA 11 + 6 − 22 + 0.
  10. iAn anembryonic pregnancy was defined as a positive s-hCG combined with the absence of a gestational sac on ultrasound at 7 weeks of gestation and/or a low initial serum hCG level that subsequently declined to zero before the scheduled 7-week scan.
  11. jPopulation means 414 participants in the ICSI group and 408 participants in the c-IVF group.
  12. s-hCG, serum human chorionic gonadotropin; GA, gestational age.
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