Hello Thanks for writing to us with your health concern. Basically, just based on the BPD, its difficult to say if you will have a normal delivery. A lot of factors determine your chances of delivering vaginally. The most important one is the relative size of the baby s head in comparison to the mother s pelvis. Even if the baby s BPD measures 90 mm, if your pelvis is roomy enough, then normal delivery maybe attempted. At 37 weeks, it is slightly too early to say if you will have a normal delivery. Even till the terminal stages of labour , problems in head delivery might occur due to various reasons. It is only close to term ( 39 weeks plus ) that your doctor would perform an internal per vaginum examination that will tell you if normal delivery is likely. You can engage in pelvic exercises and stretching and yoga to facilitate labour. Try and walk daily each evening for an hour, briskly as much as you can. Also, you can upload the latest ultrasound scan reports so that I can have a better opinion of the baby size. Please write in with more details for further discussion at - http://doctor.healthcaremagic.com/doctors/dr-aarti-abraham/64623 Take care.