Same here. I was diagnosed with serious pre-eclampsia at 35 weeks gestation age more than 2 years ago. Dear son born underweight at 1.99kg at birth. Except for height and weight, my son's developmental growth was on par with his peers of the same age (Chornological age). Before he turned 2 his height and weight usually falls at 10 percentile or 25 percentile and finally caught up with his peers at 2 years old at 50 percentile. He started to climb sofa at 9 months and walk at 12 months old. So dont't worry too much.