Open maternal-fetal surgery is currently used on fetuses with myelomeningocele (MMC). Fetoscopic or minimal access fetal surgery is also being used to treat fetuses with congenital diaphragmatic hernia (CDH). Following accurate diagnosis of a congenital malformation such as MMC or CDH, prospective parents face a range of uncertainties regarding the future of their unborn child, and the options provided require major ethical considerations. In the situation under study, termination of pregnancy may be for some parents an alternative option to expectant prenatal management. Fetal therapy provides a tantalising third option for some, where procedures are undertaken to reduce the likelihood of a more complicated neonatal course, potentially improving long term outcome, but at risk of amniotic fluid leakage, infection and most importantly very preterm delivery, itself associated with significant neonatal mortality and morbidity and long-term consequences. Balancing these competing risks is challenging. For an intervention to be effective it also needs to be acceptable to women and their families. Acceptability can be defined as a multi-faceted construct that reflects the extent to which people delivering or receiving a healthcare intervention consider it to be appropriate, based on anticipated or experienced cognitive and emotional responses to the intervention. With this study it is the aim to assess how women (and their partners) perceive the acceptability of a fetal surgical intervention for MMC and CDH. Participants will be asked to share their thoughts, views, feelings and experiences with regards to the decision to participate in fetal surgery. Data are collected by the use of in-depth face-to-face interviews. In-depth interviews are used to understand the participant's perspectives and perceptions of a situation they are in. It explicitly includes participants interpretation and understanding of an event The interviews will be held in two or three moments in time (for parents opting for fetal surgery, there will be one additional interview, after the intervention while admitted in hospital): after counselling for options, but before eventual intervention; for intervention group shortly after the intervention, and 12 weeks after birth of the baby, or termination of pregnancy.