**5. Drawbacks of fetal surgery**

The drawbacks of fetal surgery, includes bleeding, amniotic fluid leak, chorioamnionic separation, chorioamnionitis, premature rupture of membranes, preterm labor, preterm birth, and fetal loss. Premature rupture of membranes, preterm labor is the most common complication of minimally invasive fetal surgery, with high morbidity, including oligohydramnios, chorioamnionitis, and preterm delivery. However, accurate analysis of the frequency of these complications are difficult due to variations in both the assessment of the complication as well as reporting methods. Factors increasing the risk during minimally invasive fetal procedures include the number of ports and the diameter of the used instruments. A systematic review of 1376 minimally invasive fetal procedures for lower urinary tract obstruction, and twin reversed arterial perfusion reported that increased diameter of the instrument and increased number of ports are major predictors of iatrogenic premature rupture of membranes [36–38].

Following open fetal procedure, risk of hysterotomy scar weakness may interrupt both current and future labor. Some cases of uterine scar rupture after open fetal procedure was reported, starting from the second trimester, may be caused only by the uterine distension (with no uterine contractions) which form significant risk to both mother and fetus. Moreover, maternal counseling about the risk of delivery complications must be considered. On the other hand, minimally invasive fetal procedures do not preclude vaginal delivery. However, long-term follow-up of subsequent pregnancies after these procedures is not available, beside the complications of repeat caesarian section, significant advantage of minimally invasive fetal procedures should be considered [39, 40].
