and abnormal cranial imaging following single intrauterine fetal demise.
Study identifier Study Design
Data Collection
Patient selection
Population Follow-up
Axt (1999) Cohort Retrospective NS Location: Germany Year: 1992-1998
Description: 185 twin pregnancies. 7 twin pregnancies included with sIUFD.
Death of twin confirmed by ultrasound.
Placenta examined histologically to confirm chorionicity.
Additional: Confounders of TTTS, fetal anomaly and maternal illness recorded
NS
† Baghdadi (2003) Cohort Prospective Consecutive Location: UK Year: 1996-1998
Description: 252 twin pregnancies. 17 cases of sIUFD included. Excluded 14 cases as either; fetal anomaly on US, loss to follow-up or mothers medical condition. Placenta examined histologically to confirm chorionicity.
Additional: Kaplan –Meir analysis of survival. Confounders of TTTS, fetal anomaly and maternal illness recorded
11 cases lost to follow up out of 252 (4.4%)
Bajoria (1999) Cohort Multi- centre
Retrospective NS Location: UK Year: 1980-1998
Description: 3 hospitals included. 101 cases of twin pregnancy. Outcome of 92 pregnancies included. 9 cases excluded as type of
anastomoses/neonatal data not present. Also excluded if had abortion, acardiac twin or delivered before 20 weeks. Histological confirmation of chorionicity recorded.
NS
Design Collection selection
Additional: Information on confounders TTTS and maternal illness were recorded but not congenital anomaly.
† Chelli (2009) Cohort Retrospective NS Location: France Year: 2000-2008
Description: 1107 twin pregnancies. 33 included with sIUFD. Histological confirmation of chorionicity recorded Additional: Information on confounders TTTS, maternal illness and congenital anomaly recorded.
Cranial ultrasound at day 7 post delivery in 100% survivors
† Fichera (2009) Cohort Retrospective NS Location: Italy Year: 2001-2006
Description: 22 twin pregnancies with sIUFD included. Excluded MCMA twins and sIUFD in first trimester and
termination of pregnancy. We excluded one case as there was no gestational age of sIUFD. We included 21 cases.
Chorionicity determined by US.
Additional: Details on confounding factors; TTTS, maternal illness and fetal anomaly recorded.
Follow up of surviving twin in 18/20 cases (85%). Follow up ranged from 12 months-56 months
Fusi (1990) Cohort Retrospective NS Location: UK Year: 1977-1988
Description: 485 twin pregnancies. 11 cases of sIUFD included from first hospital. An additional 5 cases from a second hospital. Excluded if death occurred during labour or within a week of delivery. Death of twin confirmed by US. Placenta examined histologically to confirm chorionicity
Additional: Maternal illness as a
NS
Design Collection selection
confounder was recorded but TTTS and congenital anomaly were not.
Gaucherand (1994)
Cohort Retrospective NS Location: France Year: 1985-1992
Description: 248 multiple pregnancies.
10 cases of sIUFD included 9 twins and 1 triplet pregnancy also included 1 cases of abortion. Excluded 3 cases where both fetuses dies simultaneously We excluded the triplet pregnancy and the abortion pregnancy to for our own criteria. 8 cases included.
Additional: Data on TTTS and maternal illness as potential confounders
included but not congenital anomaly.
NS
† Hagay (1986) Cohort NS NS Location: Israel Year: 1969-1983
Description: 1192 multiple pregnancies.
21 cases of sIUFD recorded 1 set triplets and 20 twins. Chorionicity determined histologically. We excluded the case of triplets and 9 further cases where the gestational age of sIUFD was not recorded.
Additional: Data on maternal illness was recorded but TTTS and congenital anomaly were not.
NS
Ishimatsu (1994) Cohort NS NS Location: Japan
Year: 1986-1992
Description: 100 twin pregnancies. 15 cases of sIUFD included. Death of twin confirmed by US. Histological
assessment placental chorionicity in all cases.
NS
Design Collection selection
Additional: Information on congenital anomaly recorded but not TTTS or maternal illness.
Jou (1996) Cohort Prospective Consecutive Location: Taiwan Year: 1991-1995
Description: Monochorionic pregnancies only 14 cases included. sIUFD
confirmed by US. Excluded 2 cases where 2nd twin was terminated.
Placenta chorionicity determined histologically.
Additional: Presence of TTTS was noted but congenital anomaly and maternal illness was not.
NS
Kilby (1994) Cohort Retrospective NS Location: UK Year: 1988-1993
Description: 342 twin pregnancies 20 cases of sIUFD after 20 weeks. Death of one twin was confirmed by US.
Placentas examined histologically for chorionicity.
Additional: Details on congenital anomaly, maternal illness and karyotyping. TTTS not recorded
NS
† Krayenbuhl (1998)
Cohort Retrospective NS Location: Switzerland Year: 1984-1994
Description: 541 twin pregnancies. 19 cases of sIUFD included. Chorionicity determined histologically. sIUFD in first trimester excluded.
Additional: Data on TTTS and congenital anomaly but not maternal illness.
?
Design Collection selection
Lin(1999) Cohort Retrospective NS Location: Taiwan Year: 1988-1997
Description: 302 twin pregnancies. 17 sIUFD pregnancies included. We excluded 5 cases as chorionicity was not known. Did not include how
chorionicity or gestational age of sIUFD were examined and therefore only used for calculating neurological impairment.
Additional: No data on confounders TTTS, congenital anomaly and maternal illness.
NS
Malinowski (2000) Cohort Prospective Consecutive Location: Poland Year: 1989-1999
Description: 11 cases of sIUFD recorded. Placenta examined histologically.
Additional: Pregnancies all in the second trimester. Data on TTTS, congenital anomaly recorded but not maternal illness.
NS
† Malinowski (2003)
Cohort Multi- centre
Retropective NS Location: Poland Year: NS
Description: 295 twin pregnancies. 12 cases of sIUFD
Additional: Pregnancies all in the third trimester. Data on congenital anomaly and maternal illness recorded but not TTTS
NS
Petersen (1999) Cohort Retrospective NS Location: Denmark Year: 1991-1995
Description: 310 twin pregnancies.
sIUFD occurred in 13 pregnancies. We excluded 2 as one was a triplet
Follow-up of 4 out of 8
surviving twins (50%) at an average of 19
Design Collection selection
pregnancy and one has not determined chorionicity and analysed 11.
Histopathological examination of chorionicity for all cases.
Additional: Information on TTTS,
congenital anomaly and maternal illness as potential confounders recorded.
months range 8-51 months.
Saito (1999) Cohort Retrospective NS Location: Japan Year: 1971-1997
Description: 481 cases of twins. 30 cases of sIUFD. Method of determining chorionicity and gestational age of twin demise not recorded.
Additional: Confounders such as TTTS congenital anomaly and maternal illness recorded
NS
Santema (1995) Case- control
Prospective Consecutive Location: The Netherlands Year: 1973-1993
Description: 29 consecutive cases of sIUFD. iUFD confirmed by US and all had sIUFD over 20 weeks. Placentas were examined histologically to
determine chorionicity. 58 pregnancies in control group.
Additional: Data on congenital anomaly, maternal illness recorded but not TTTS.
Follow up available for 19 out of 22 surviving twins (86%), median age of follow up 4 years and 2 months, range 2 months to 18 years.
†Szymonowicz (2009)
Cohort Retrospective NS Location: Australia Year: NS
Description: 6 cases of sIUFD all diamniotic monochorionic. How gestational age of sIUFD and chorionicity were determined is not recorded.
Follow-up for 2 out of 2 cases that survived (100%) at 3 and 5 years of age
Design Collection selection
Additional: Data on TTTS, congenital anomaly and maternal illness as potential confounders is not recorded Van Heteren
(1998)
Cohort Retrospective NS Location: The Netherlands Year: 1990-1996
Description: Only included if sIUFD of monochorionic twin pregnancy and TTTS present. 11 cases included.
Chorionicity was determined histologically.
Additional: Data on TTTS, congenital anomaly were recorded but not concurrent maternal illness.
Follow-up of the eight survivors (100%) at 1.5-3 years of age.
Wang (2000) Cohort Twin centre
Retrospective NS Location: Taiwan Year: 1993-1998
Description: 9 cases of sIUFD recorded all monochorionic with a diagnosis of TTTS. Not recorded how chorionicity of gestation of sIUFD was derived.
Additional: No record of potential confounders; maternal illness and congenital anomaly
NS
Woo (2000) Cohort NS NS Location: Hong Kong
Year: 1993-1997
Description: 182 twin pregnancies. 7 cases of sIUFD included. We excluded 3 as the choronicity was not recorded in one case and the gestation of sIUFD was not recorded in 2 cases.
Chorionicity was confirmed histologically.
Additional: Confounders; TTTS,
maternal illness and congenital anomaly were recorded
All 6 surviving twins were followed-up (100%) but timings of follow-up were not recorded.
