Gestação gemelar momento e via de parto Ben Willem Mol CMGO 2015

Gestação gemelar Momento e via de parto Prof Ben Mol Department of Obstetrics & Gynaecology University of Adelaide

Twins: where do they come from

%

N

1276

1264 1178 1200 1170 1122

976

902

=

9088

Gestação gemelar: Momento de parto

Meta-analysis for prospective risk of stillbirth was undertaken by a competing-risk survival analysis, with delivery as a competing event.

For neonatal outcomes, we fitted multilevel random effects logistic regression models.

Appendix 4: Cumulative risk of stillbirth and weekly risk of neonatal death in monochorionic and dichorionic twin pregnancies after 34 weeks’ gestation Stillbirth (DCDA)

0

2

4

6

Cumulative risk (x1000)

8

Stillbirth (MCDA)

34+0 - 34+6

35+0 - 35+6

36+0 - 36+6

37+0 - 37+6

38+0 - 38+6 34+0 - 34+6

36+0 - 36+6

37+0 - 37+6

38

Neonatal death (DCDA

20 10 0

Risk (x1000)

30

Neonatal death (MCDA)

35+0 - 35+6

34+0 - 34+6

35+0 - 35+6

36+0 - 36+6

37+0 - 37+6

38+0 - 38+6 34+0 - 34+6

35+0 - 35+6

36+0 - 36+6

37+0 - 37+6

38

Stillbirth (DCDA)

0

2

4

6

8

Stillbirth (MCDA)

34+0 - 34+6

35+0 - 35+6

36+0 - 36+6

37+0 - 37+6

38+0 - 38+6 34+0 - 34+6

36+0 - 36+6

37+0 - 37+6

38+0 - 38+6

39+0 - 39+6

Neonatal death (DCDA)

10

20

30

Neonatal death (MCDA)

35+0 - 35+6

0

Risk (x1000)

Appendix 4: Cumulative risk of stillbirth and weekly risk of neonatal death in monochorionic and dichorionic twin pregnancies after 34 weeks’ gestation

34+0 - 34+6

35+0 - 35+6

36+0 - 36+6

37+0 - 37+6

38+0 - 38+6 34+0 - 34+6

35+0 - 35+6

36+0 - 36+6

37+0 - 37+6

38+0 - 38+6

39+0 - 39+6

Steroids

Steroids Glucocorticoid-exposed children were twice as likely to be identified as being in the lowest achievement group at school compared with the control group (33 of 186 [17.7%] vs 14 of 164 [8.5%]) relative risk, 2.1; 95% CI, 1.1-3.7; P = .01).

Stutchfield PR Arch Dis Child Fetal Neonatal Ed. 2013;98:F195-F200.

Timing of delivery • Taking into account the risks of stillbirth and neonatal death, clinicians should consider delivery at 36+0 to 6 weeks in monochorionic and at 37+0 to 6 weeks in dichorionic twin pregnancies.

Gestação gemelar: Via de parto

Death of either twin at term • Risk of death by mode of delivery Planned CD: 1.4 per 1,000 Other: 5.2 per 1,000 • Risk difference 3.79 per 1,000 (95% CI=1.24-6.34) • Odds ratio for planned CD 0.26 (95% CI 0.03–1.03)

• Driven by increased risk of death of the second twin Smith GCS et al, BJOG 2005;112:1139-1144

Roberts et al.

• Planned caesarean section and first twin at term –RR = 1.01, 95% CI 0.31–3.29 • Planned caesarean section and second twin at term –RR = 0.24, 95% CI 0.09–0.63 • Absolute risk reduction with pre-labor cesarean was 4.9 per 1,000 deliveries Roberts et al, Obstet Gynecol. 2015;125:103-10

How many women did I say you would need for a trial? “With a rate of 3 deaths of second twins due to intrapartum anoxia per 1000 deliveries, allowing 80% power for a one sided test, and assuming that the rate of perinatal death in the planned caesarean group is zero, a randomised controlled trial would need to recruit about 6500 women with twin pregnancies [at term]� (BMJ 2002)

What did we say about including preterm births?

• “Inclusion of preterm births may mask a protective effect of caesarean section on perinatal mortality if the principal effect of caesarean section is to reduce the risk of complications for the second twin (BMJ 2007)”

Why just preterm?

• The additional risk of death/severe morbidity of the second twin is in the region of 0.5 to 1% • If you have a study where a large proportion of women deliver preterm, the vast majority of the adverse outcomes in both arms of the trial will be due to prematurity • We have shown that the increased risk of death of the second twin can only be measured at term Smith GCS et al, BMJ 2002;325:1004; BJOG 2005;112:1139-1144; BMJ. 2007;334:576

Recruited 2,726 women Recruitment from 32 weeks onwards ~50% delivered preterm

The Twin Birth Study • No significant difference in the primary outcome between the plannedcesarean-delivery group and the planned-vaginal-delivery group – OR planned CD = 1.16, 95% CI 0.77 to 1.74

• However, most of the primary outcomes in both arms of the trial will have been due to preterm birth

Less than 500 women recruited at term

Conclusions • Monochorionic twin 36+0 to 6 weeks • Dichorionic twin 37+0 to 6 weeks • Do not use corticosteroids for fetal ripening for elective CS • Vaginal delivery of twins is associated with a poor outcome rate of 3/1000 (second twin)

A day without randomisation is a day without progress

Um dia sem randomização Ê um dia sem progresso

Twitter @bwmol ben.mol@adelaide.edu.au www.globalobstetricsnetwork.org/