I would be fine with a baby taking night feeds once in 3 hours but stretching it to 4 hours is still worrisome for me, considering this baby is born preterm. Try to feed the baby at least once in 3 hours without giving more gap than that. Also keep the frequency of morning feeds once in 2-3 hours. And watch for adequate passing of urine and weight check once in 2-4 weeks. In case of any further doubts please do consult your pediatrician. 

Morning time every 2nd hourly and night time atleast 3rd hourly

I totally understand your concern. Before suggesting treatment, I would like to ask a few questions to ensure the correct management can be provided. Contact me on Practo or WhatsApp chat. Contact number: 97012307 two nine Dr. G. Avinash MBBS, MD (Pediatrics) Fellowship in Neonatology

Preterm or term the frequency is 2nd hrly , during night time gap may be 3-4 hrs some times , instead of focusing on frequency focus on: 1 adequate urine output atleast 4-5 times daily 2 adequate wt gain check weekly 3 target 9-10 feeds/day

Feed should be give 2 hourly

Yes, 3–4 hr gap at night is fine if baby is gaining weight well and passing urine normally. In daytime, try not to exceed ~2.5–3 hrs gap. Follow baby’s demand cues, no need to wake at night if weight gain is good.