Twins pregnancy

1. น.พ. ธีระ ทองสง
ภาควิชาสูติศาสตร์และนรีเวชวิทยา
คณะแพทยศาสตร์ มหาวิทยาลัยเชียงใหม่

2. 2 sperms, 2 eggs
Incidence : variable
Fetal sex : same or different
Membranes : dichorionic, diamnionic
Placenta : one fused or two separate

3. Incidence : 1:250 pregnancies
Fertilization : 1 sperm, 1 egg
Fetal sex : same (except XO,XY)
Placenta : one fused or separate
(two separate : dichorionic)
Division of zygote : depend on day of twinning

6. Twin-specific Complication (%)
Type of Twinning
Twins
(%)
Fetal Growth
Restriction
Preterm
Delivery
Placental
Vascular
Anastomosis
Perinatal
Mortality
Dizygotic 80 25 40 0 10-12
Monozygotic 20 40 50 15-18
-Diamnion/dichorion 6-7 30 40 0 18-20
-Diamnion/monochorion 13-14 50 60 100 30-40
-Monoamnion/monochorion <1 40 60-70 80-90 58-60
Conjoined Twins 0.002 -
0.008
— 70-80 100 70-90

7. History :
Weak : maternal family history, advanced maternal age,
high parity, large maternal size
Strong : recent clomiphene citrate or gonadotropins,
Assisted reproductive techniques (ART)
Clinical examination : size > date (2nd trimester)
Ultrasound : separate gestational sac, 2 head
or abdomen in the same plane

8. Chorionicity
Dichorion :
twin peak sign (lambda sign)
thick dividing membrane
(> 2 mm)
separate placenta
Monochorion :
T sign
Zygosity
genetic testing
sex

10. 3500 kcal/day
Iron (60 mg/day)
Folic acid (1 mg/day)
Calcium (2000 mg/day)
TWG 16 – 20 kg at term
DM screening (as same as singleton)

11. Serial U/S in 2nd and 3rd trimester
Monochorionic twins
every 2 – 3 wks in 2nd trimester
Dichorionic twin
every 4 – 6 wks in 2nd trimester (or after 20 wks)
Frequent scans if FGR or growth discordance

12. Antepartum testing in uncomplicated twin
No benefit
Indicated in
IUGR
Discordant growth
Abnormal amniotic fluid volumes
Monoamniotic twins
Preeclampsia
NSTs or BPPs 1 – 2 weekly

13. Bed rest
Is often recommended for prevention of preterm labor
RCTs of hospitalization or bed rest in twin  failed to prolong GA
Home uterine monitoring
Effectively detects contractions predictive of preterm labor
There are no data that it improves neonatal outcome

14. Measurement of cervical length
Routine U/S for cervical length : not recommended
Fetal fibronectin
Routine fFN test of asymptomatic women : not recommended
Cerclage
RCT of prophylactic cerclage in twin : no benefit
Tocolytic drugs
Routine tocolysis for asymptomatic women : not effective

16. 2 skilled OB attendants for labor and delivery
Anesthesiologist available at delivery
Neonatal care personnel
Portable ultrasound scanner
Reliable IV access
CTG with dual monitoring capability
Delivery bed with lithotomy stirrups
Forceps or vacuum
Oxytocin infusion
Tocolytic agent for uterine relaxation
Methergine, 15-methyl PGF2 alpha or both
Immediate availability of blood
Capabilities and staff for emergency C/S

17. Latent phase
Active phase
Epidural block
Hypotonic uterine dysfunction
Hypocontractility after delivery of first twin
Postpartum hemorrhage

18. Vertex-Vertex
Vertex-Nonvertex
Nonvertex

19. Vaginal delivery
Time interval between deliveries of twins
Fetal distress
Instrumental delivery (vacuum, forceps)
Internal podalic version
Cesarean section

20. Clamp umbilical cord of twin A
PV, U/S
A short period of uterine quiescence 
external manipulation of twin B if necessary
Oxytocin IV infusion to resume uterine contraction
(if no contraction within 10 min)
Amniotomy when the head engage

21. Mean interval 21 min (2/3 interval < 15 min)
ACOG 1998  interval between delivery of twins
is not critical in determining the outcome of 2nd twin
Umbilical cord blood gas deteriorate with increasing time interval
Maximum time limit of 30 min with documentation of reassuring FHR pattern

22. There is a clear, emergent OB indication
EFW > 1500 gm
Experienced operator
Available anesthesia for effective Uterine relaxation
Simultaneous preparation for emergency C/S

24. Vaginal delivery
Breech extraction of 2nd twin (partial or total)
External cephalic version of 2nd twin
Cesarean delivery of 2nd twin
Cesarean delivery of both twins

25. Vaginal breech delivery of 2nd twin
increase risk of mortality
C/S delivery is associated with the lowest rate
of neonatal morbidity and mortality

26. Observational, non-RCT study :
no increased risk of adverse neonatal outcome
Only 1 RCT prospective
Maternal fever (11.1% vs 40.7%)
Postpartum hospitalization (4.9 vs 8 days)
Neonatal hospitalization (8.0 vs 13.1 days)
Success rate > 95%

27. Operator must be experienced in Vg breech delivery
Should be avoided if
EFW of Twin B > Twin A 500 gm
EFW of Twin B < 1500 gm
Emergency conditions
Total breech extraction
C/S

28. An alternative for fetuses not appropriate for vaginal breech delivery
Literature review
5 series reviewed, 118 patients
Successful Vg deliveries (58% vs 98% in breech extraction)
Complications (10% vs 1% in breech extraction)
Cord prolapse (5% vs 0.3% in breech extraction)
More likely to undergo abdominal delivery than breech extraction

30. Comparison of BE of 2nd twin, ECV of 2nd twin, C/S of both
Healthy newborn
BE > ECV and C/S
Ventilator requirement
C/S > ECV> BE
Length of stay
C/S > ECV> BE
Charges
C/S > ECV> BE
Vaginal breech extraction of nonvertex 2nd twin provides equivalent, if not superior,
outcomes at a lower cost

31. Limited data to support C/S delivery
Transverse
Breech (EFW < 1500 or > 1500 gm)
Interlocking of fetal heads
Interference of 2nd twin on descent of 1st twin deflection of head
Inadequately dilate of cervix
ACOG recommends C/S delivery of a nonvertex presenting 1st twin

33. C/S does not eliminate the possibility of a technically difficult or traumatic birth
Type of uterine incision should be based on
Size and weight of twins
Skill of the operator
Degree of development of lower uterine segment

34. The worst of both worlds
A tiring and often risky pregnancy
A tiring labor
A major abdominal operation
Two lots of stitches
Two new babies to care for

35. 9.5%
Increase C/S rate, increase combined delivery
1/3 of vertex-nonvertex twin
No one intentionally plans a combined delivery
If – for whatever reason – safe vaginal delivery of twin B cannot be expected,
no need to test one’s ability to handle cataclysmic situations

36. Premature twins
Prior cesarean

37. Vertex-Vertex
Vertex-Nonvertex
Increase perinatal asphyxia and birth trauma in
very low birth weight twin with vaginal breech delivery
ACOG conclude that C/S of nonvertex 2nd twin EFW< 1500-2000 gm
is an appropriate management option

38. Should not be an absolute contraindication to vaginal delivery of twins
Success rate 30-75%
Risk of uterine rupture is the same as VBAC in singleton

39. Twin A Vertex
Twin B Vertex
Twin A Vertex
Twin B Nonvertex
Twin A Nonvertex
EFW > 1500 g EFW < 1500 g
Twin B > 500 g larger than twin A
Contraindication to Vg breech delivery
Twin A; Vx Vg delivery
Twin B; Br Vg delivery C/S both twinsIntrapartum ECV
Success Unsuccess
Vx Vg delivery
of both twins
Combined
Vg-C/S delivery
C/S of both twinsVg delivery of both twins