Re: 14 week old baby, dropping weight percentiles?
Welcome to the forum!
I think the pediatrician's lack of concern trumps the concern from the HV. Everything your baby is doing sounds entirely normal- he's producing plenty of diapers and the poops are yellow. At is nursing frequency is a little low but still in the normal range. Nursing is pain-free.
What may be happening is something called catch up/catch down growth, where a baby follows one growth trajectory inside the womb but a different one outside the womb. This means that babies can be born small or average and shoot up to the top of the charts, or be born big or average and then decline to a lower curve. What is important is that the baby continue to grow and develop normally as he wiggles around on the charts. Declining on the charts is not in and of itself a concern- just an indicator to watch the baby a little more carefully.
One thing that you might want to think about changing is that long, long sleep stretch at night. Some very placid babies and/or babies who are content to get their sucking needs met with a thumb or pacifier will not eat enough to grow at their optimum rate. I would think about adding in 1-2 "dream feeds" at night- just wake the baby right before you go to bed and nurse him, and then nurse him again if you get up to pee or something. That increase in intake might be enough to give him a boost on the chart.
You also might want to consider taking away any sleep-extending techniques like swaddling, using a swing, or a pacifier (though it sounds like your son is a thumb guy and there's no way to take his thumb away!). Some babies sleep less "well" and eat more when those things are taken away.
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