Department of Perinatology and Gynaecology, Wilhelmina Children's Hospital, University Medical Centre, Utrecht, The Netherlands.
Early Hum Dev. 2012 Mar;88(3):129-34. doi: 10.1016/j.earlhumdev.2011.07.011. Epub 2011 Aug 5.
A prospective study was performed to compare fetal behavioral development in healthy dichorionic twins and singletons, and identify twin intra-pair associations (synchrony) of fetal movements and rest-activity cycles using different criteria to define synchrony.
Twenty pregnant women carrying dichorionic twins participated. Serial simultaneous 1-hr recordings of fetal movements were made on twins between 11 and 40 weeks' gestation (wGA) using two ultrasound machines. All twins were born healthy after 36 wGA and of appropriate weight for gestation. The incidences of fetal generalized body movements (GM) and breathing movements in twins were compared with institutional reference values for singletons. A comprehensive smoothing procedure on the raw movement data was performed to evaluate previously reported variation in twin intra-pair synchrony.
Twin fetuses were less active (GM) than singletons throughout pregnancy, but their breathing activity was higher in the third trimester. The incidences of fetal GM, quiescence, and breathing were fairly correlated within twin pairs. However, the temporal association or simultaneous occurrence of these activities was poor, especially after 30 weeks' gestation, coinciding with emerging rest-activity cycles. There was no evidence of a consistently more active ('dominant') twin half. Potential confounders had no effect on behavioral development in fetal twins.
The results show differential behavioral development between normal dichorionic fetal twins and singletons. Within fetal twin-pairs, we found poor synchrony of movements and independent occurrence of rest-activity cycles. Previous research on fetal twin behavior appears to have overestimated the degree of intra-pair movement synchrony.
本前瞻性研究旨在比较健康的双绒毛膜双胞胎和单胎胎儿的行为发育，并使用不同的同步定义标准来识别胎儿运动和静动周期的双胞胎内配对关联（同步性）。
20 名怀有双绒毛膜双胞胎的孕妇参与了该研究。在妊娠 11 周至 40 周（GA）期间，使用两台超声机对双胞胎进行了连续 1 小时的胎儿运动同步记录。所有双胞胎均在妊娠 36 周 GA 后健康出生，且体重适合胎龄。将双胞胎的全身运动（GM）和呼吸运动发生率与单胎的机构参考值进行了比较。对原始运动数据进行了全面平滑处理，以评估先前报道的双胞胎内配对同步性的变化。
整个孕期，双胞胎胎儿的活动（GM）水平低于单胎，但在孕晚期，其呼吸活动较高。双胞胎胎儿的 GM、静止和呼吸活动发生率在双胞胎内配对中相当相关。然而，这些活动的时间关联或同时发生情况较差，尤其是在妊娠 30 周后，此时出现了静动周期。没有证据表明存在始终更活跃（“主导”）的双胞胎。潜在的混杂因素对胎儿双胞胎的行为发育没有影响。
结果表明，正常双绒毛膜胎儿双胞胎和单胎之间存在不同的行为发育。在胎儿双胞胎内配对中，我们发现运动同步性较差，且静动周期独立发生。之前关于胎儿双胞胎行为的研究似乎高估了配对内运动同步性的程度。
