Zhao D, Slaghekke F, Middeldorp J M, Duan T, Oepkes D, Lopriore E
Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
Division of Fetal Medicine, Department of Obstetrics, Leiden University Medical Center, Leiden, The Netherlands.
Placenta. 2014 Dec;35(12):1070-4. doi: 10.1016/j.placenta.2014.09.019. Epub 2014 Oct 7.
Twin anemia-polycythemia sequence (TAPS) is a newly described form of chronic twin transfusion. Previous observational studies noted a discordance between birth weight and individual placental share in TAPS. The purpose of this study was to investigate if fetal growth in monochorionic (MC) twins with TAPS is determined by placental share or by the net inter-twin blood transfusion.
All consecutive MC twin placentas of live-born twin pairs with and without TAPS examined at our center between June 2002 and February 2014 were included in this study. Hemoglobin (Hb) levels and individual placental share were evaluated at birth and correlated with birth weight share. We excluded MC twin pregnancies with twin-twin transfusion syndrome.
A total of 270 MC twin pregnancies (TAPS group, n = 20; control group without TAPS, n = 250) were included in this study. Donors with TAPS had a lower birth weight than recipients in 90% (18/20) of cases, but a larger placental share in 65% (13/20) of cases. In the TAPS group, birth weight share was positively correlated with Hb share at birth (P < 0.01) but not with placental share (P = 0.54). In the control group without TAPS, birth weight share was strongly correlated with placental share (P < 0.01) but not with Hb share (P = 0.14).
A relatively larger placental share may enable the survival of the anemic twin in TAPS.
In contrast with uncomplicated MC twins, fetal growth in MC twins with TAPS is determined primarily by the net inter-twin blood transfusion instead of placental share.
双胎贫血-红细胞增多序列征（TAPS）是一种新描述的慢性双胎输血形式。既往观察性研究指出，TAPS中出生体重与个体胎盘份额之间存在不一致。本研究的目的是调查患有TAPS的单绒毛膜（MC）双胎的胎儿生长是由胎盘份额还是双胎间净输血决定。
本研究纳入了2002年6月至2014年2月期间在我们中心检查的所有连续的有或无TAPS的活产双胎对的MC双胎胎盘。在出生时评估血红蛋白（Hb）水平和个体胎盘份额，并将其与出生体重份额相关联。我们排除了患有双胎输血综合征的MC双胎妊娠。
本研究共纳入270例MC双胎妊娠（TAPS组，n = 20；无TAPS的对照组，n = 250）。90%（18/20）的TAPS供血儿出生体重低于受血儿，但65%（13/20）的供血儿胎盘份额更大。在TAPS组中，出生体重份额与出生时的Hb份额呈正相关（P < 0.01），但与胎盘份额无关（P = 0.54）。在无TAPS的对照组中，出生体重份额与胎盘份额密切相关（P < 0.01），但与Hb份额无关（P = 0.14）。
相对较大的胎盘份额可能使TAPS中贫血双胎得以存活。
与无并发症的MC双胎相比，患有TAPS的MC双胎的胎儿生长主要由双胎间净输血而非胎盘份额决定。
