Objective: To investigate the safety and effectiveness of radiofrequency ablation (RFA) for selective fetal reduction in complex multiple pregnancies and analyze factors affecting perinatal outcomes. Methods: This was a retrospective case series of 156 patients undergoing selective fetal reduction by RFA in Provincial Hospital Affiliated to Shandong University from July 22th, 2011 to September 12th, 2018. They were divided into five groups according to surgical indications, including 46 cases in the monochorionic twins discordant for fetal anomalies group, 42 cases in the multiple pregnancies for reducing fetal numbers group, 40 cases in the twin to twin transfusion syndrome (TTTS) group, 24 cases in the selective intrauterine growth restriction (sIUGR) group and 4 cases in the twin reversed arterial perfusion sequence (TRAPS) group. According to the gestational age at surgery, patients were divided into two groups: the gestational age at surgery <20 weeks group (75 cases) and the gestational age at surgery≥20 weeks group (81 cases). According to the cycles of RFA required for surgery, patients were divided into two groups: one cycle group (124 cases) and ≥2 cycles group (32 cases). Basic information of patients, surgical process, postoperative complications and pregnancy outcomes were recorded. The growth and development of survival newborns were also followed up. Factors affecting perinatal outcomes were analyzed. Results: (1) The median gestational age at procedure of 156 patients was 20 weeks (14⁺⁵- 29⁺¹ weeks). The median cycles of RFA was 1 cycle (1-3 cycles), of which one cycle accounted for 79.5% (124/156). (2) Eleven (7.1%, 11/156) patients experienced intrauterine fetal death, 27 (17.3%, 27/156) patients miscarried, and the overall survival rate was 75.6% (118/156). Premature birth rate before 34 weeks was 19.5% (23/118). There were 129 neonates. The median gestational age at delivery was 37⁺³ weeks (28⁺²- 41⁺¹ weeks) with a mean birth weight of (2 657±700) g. (3) Analysis of pregnancy outcomes based on surgical indications found that, the gestational age at delivery [38 weeks (30⁺¹-41⁺¹ weeks), 36⁺⁴ weeks (29- 39 weeks), 36⁺⁴ weeks (28⁺²-39⁺⁵ weeks), 38 weeks (31-39⁺⁶ weeks), 38⁺³ weeks (30⁺⁴-38⁺⁴ weeks)] and neonatal birth weight [(2 820±671), (2 435±416), (2 497±843), (2 998±718), (2 517±1 087) g] were significantly different among fetal anomalies group, reducing fetal numbers group, TTTS group, sIUGR group and TRAPS group, respectively (all P<0.05). There were no significant differences in the pregnancy outcomes between gestational age at surgery <20 weeks group and gestational age at surgery ≥20 weeks group, or between one cycle group and ≥2 cycles group, respectively (all P>0.05). Conclusions RFA is a safe and effective procedure in treating complex monochorionic multiple pregnancies. Surgical indications would affect the gestational age at delivery and neonatal outcomes.

Objective To analyze the clinical characteristics of structural malformations in one of monochorionic diamnionic twins (MCDA). Methods The clinical data of 77 MCDA patients with structural malformations diagnosed by ultrasound were retrospectively reviewed from January 2012 to May 2017. The distribution of structural malformations, prenatal chromosomal karyotyping and pregnancy outcomes were analyzed. Results (1)Among the 77 MCDA patients with structural malformations, the single malformation accounted for 79％(61/77), the multiple malformations accounted for 21％(16/77). And there were a total of 94 types of malformations, the top three malformations were neurological malformations (32％, 30/94), cardiovascular malformations (29％,27/94) and twin reversed arterial perfusion sequence (TRAPS;10％,9/94). (2)Among the 77 patients with structural malformation, 64 cases (83％, 64/77) were examined for fetal chromosomes, of whom 14 cases (22％,14/64) were examined for fetal chromosomes of both twins, with 1 case (1/14) of discordant fetal chromosome. (3)Among the 77 patients, 4 cases (5％, 4/77) with severe fetal malformations terminated pregnancy. Totally 29 cases (38％, 29/77) with severe malformations were treated with selective fetal reduction, among whom 7 cases (24％, 7/29) experienced unexplained fetal death within 24 hours after the operation;2 cases (7％, 2/29) happened inevitable abortion, and 2 cases (7％, 2/29) underwent unexplained fetal death during the late pregnancy. Of the remaining 44 patients (57％,44/77) with expectant treatment, 13 cases (30％, 13/44) occurred twin transfusion syndrome (Ⅱ-Ⅳ), and were treated with fetoscopic laser occlusion. Eight patients had 2 survival twins, 4 patients delivered 1 survival twin, and 1 patient had dead twins. Conclusions The most common malformations in MCDA twins are the nervous malformations, cardiovascular malformations and TRAPS. The chromosome karyotype of MCDA twins with structural malformations are sometimes discordant, and separate samling of the twins is suggested for prenatal diagnosis. Selective fetal reduction could be given to severe structural malformation in MCDA patients safely and effectively. For non-severe structural malformation in MCDA patients with twin transfusion syndrome, fetoscopic laser occlusion is safe and effective.