A Study On The Timing Of Second-Trimester Multifetal Pregnancy Reduction

OBJECTIVE:The purpose of this study was to evaluate the outcomes of multifetal pregnancy reduction(MFPR) performed at 12-14+6 weeks gestation or 15-16+6weeks gestating or 17-24+6 weeks gestation and to determine which timing better outcomes and to investigate the safety and effectiveness of multiple pregnancy fetal reduction. So we can find the best timing to improve the multiple pregnancy outcomes.METHODS:From Jan.2002 to Dec.2010,150 patients undergoing selective second-trimester fetal reduction in department of Obstetrics, Shandong Provincial Hospital were enrolled in this study, whom were classified into 87cases undergoing. MFPR at 12-14+6 weeks gestation in group I and 28 cases undergoing MFPR at 15-16+6weeks gestation in group II and 35 cases undergoing MFPR at 17-24+6 weeks gestation in group III. The pregnancy outcome and obstetric complications were compared among these three groups. The MFPR was performed by transabdominal ultrasound-guided intracardiac injection of 10% potassium chloride (KC1) solution.RESULTS:1 To compare the cause of multiple pregnancy fetal reduction, in second-trimesterIn Group I:The study population comprised 87 patients:86 patients just required to reduce the number of the fetus and 1 patient (1.45%) required to reduce the fetus with Structural or chromosomal abnormality.In Group II:The study population comprised 28 patients:23 patients just required to reduce the number of the fetus and 5 patients (17.86%) required to reduce the fetus with structural or chromosomal abnormality.In GroupⅢ:The study population comprised 35patients:16 patients just required to reduce the number of the fetus and 19 patient (54.29%) required to reduce the fetus with Structural or chromosomal abnormality. There were statistical difference among the three group in the cause of multiple pregnancy fetal reduction (P<0.05).2 To compare the pregnancy outcomes of patients after multiple pregnancy fetal reduction. in second-trimesterIn GroupⅠ:The study population comprised 87 patients.①77 patients finally obtain above one healthy newborn in this pregnancy.10 patients lost this pregnancy after multiple pregnancy fetal reduction.(not to obtain healthy newborn). The successful ratio of puncturing was 100% and the pregnancy loss rate was 11.49%and the successful pregnancy ratio was 88.51%.②.In the 77 cases, there were 67 cases who deliveried after 34 weeks and 9 cases deliveried at 28-32 weeks. Delivery rate of 28-34 weeks was 11.67%③Mean gestational age at delivery:Mean gestational age at delivery of reduced twins (36.76±1.87weeks) and reduced single birth (38.52±0.67weeks);④Mean birth weigh:Mean birth weigh of twinl (2452.4±399.9g) and twin2 (2778.6±439.3g); and single birth (3389.0±457.5g)In GroupⅡ:The study population comprised 28 patients.①24 patients finally obtain above one healthy newborn in this pregnancy.4 patients lost this pregnancy after multiple pregnancy fetal reduction.(not to obtain healthy newborn). The successful ratio of puncturing was 100% and the pregnancy loss rate was 14.29% and the successful pregnancy ratio was 85.71%.②.In the 24 cases there were 23 cases who deliveried after 34 weeks and 1 case deliveried at 28-34 weeks. Delivery rate of28-34 weeks was 4.17%③Mean gestational age at delivery:Mean gestational age at delivery of reduced twins (37.41±1.06weeks) and reduced single birth (39.08±5.20weeks);④Mean birth weigh:Mean birth weigh of twin1 (2555.3±364.6g) and twin2 (2757.1±347.8g); and single birth (3172.9±621.3g)In GroupⅢ:The study population comprised 35 patients.①25 patients finally obtain above one healthy newborn in this pregnancy.10 patients lost this pregnancy after multiple pregnancy fetal reduction.(not to obtain healthy newborn). The successful ratio of puncturing was 100% and the pregnancy loss rate was 28.57% and the successful pregnancy ratio was 71.43%.②.In the 25 cases there were 22 cases who deliveried after 34 weeks and 3 cases deliveried at 28-34weeks. Delivery rate of 28-34weeks was 12.00%③Mean gestational age at delivery: Mean gestational age at delivery of reduced twins (37.19±1.44weeks) and reduced single birth (37.66±2.77weeks);④Mean birth weigh:Mean birth weigh of twin 1 (2375.0±493.3g) and twin2 (2723.0±483.0g); and single birth (3132.7±671.1g)There is statistical difference between group I and group III in pregnancy loss rate(P=0.021). There were no statistically significant difference among group I and group II and group III regarding delivery rate of 28-34weekso,mean gestational age at delivery, mean birth weigh.3 To compare the obstetric complications of patients after multiple pregnancy fetal reduction, in second-trimesterIn Group I:The study population comprised 87 patients.77 patients finally obtain above one healthy newborn in this pregnancy.①In the 77cases, there were 62 cases who reduced twins. Among this 62 cases, there were 10 cases who occur birth weight discordance and 52 cases did not have this phenomenon The rate of birth weight discordance was 16.13%②There were 8 cases who occur pregnancy-induced hypertension and 19 cases did not occur. The rates of pregnancy-induced hypertension was 9.20%③There were 2 cases who occur gestational diabetes and 85 cases did not occur. The rates of gestational diabetes was 2.30%.In Group II:The study population comprised 28 patients.24 patients finally obtain above one healthy newborn in this pregnancy.①In the 24 cases, there were 17 cases who reduced twins. Among this 17 cases there were 1 cases who occur birth weight discordance and 16 cases did not have this phenomenon The rate of birth weight discordance was 5.88%;②There were 3 cases who occur pregnancy-induced hypertension and 25 cases did not occur. The rates of pregnancy-induced hypertension was 10.71%③There were 1 cases who occur gestational diabetes and 27 cases did not occur. The rates of gestational diabetes was 3.57%.In Group III:The study population comprised 35 patients.25 patients finally obtain above one healthy newborn in this pregnancy.①In the 25 cases there were 10 cases who reduced twins. Among this 10 cases there were 3 cases who occur birth weight discordance and 7 cases did not have this phenomenon. The rate of birth weight discordance was 30%;②There were 5 cases who occur pregnancy-induced hypertension and 30 cases did not occur. The rates of pregnancy-induced hypertension was 14.29%③There were 2 cases who occur gestational diabetes and 33 cases did not occur. The rates of gestational diabetes was 5.71%.Among the three groups was no statistically significant difference in the rate of birth weight discordance, the rates of pregnancy-induced hypertension, gestational diabetes.CONCLUSIONS:1 Second-trimester multifetal pregnancy reduction is a simple, well-targeted, secure, reliable,effective and minimally invasive method. It can reduce fetal numbers, in order to effectively improve the outcome of pregnancy, length gestational age, reduce pregnancy complications, improve the successful pregnancy rate, increase birth weight, and improve birth quality.2 After prenatal screening or prenatal diagnosis in second-trimester performing multifetal pregnancy reduction can effectively reduce fetus with appearance malformations or chromosomal abnormalities and retain normal fetus, which can reduce pregnancy complications, improve the successful pregnancy rate, increase birth weight, and improve birth quality.3 It is significantly effective to improve the pregnancy outcome and the successful pregnancy rate to perform multifetal pregnancy reduction at 12-14+6 weeks gestation. However the fetal abnormality was not detected easily during this period.4 It can not only improve the pregnancy outcome and the successful pregnancy rate to perform multifetal pregnancy reduction at 15-16+6weeks gestation, but also can provide the timing for prenatal screening or prenatal diagnosis 5 The detection rate of fetal abnormality was the highest to perform multifetal pregnancy reduction at 17-24+6 weeks gestation. However, performing multifetal pregnancy reduction during this period can have the possibility to increase the risk of the pregnancy loss rate.