At 28 weeks your baby is around 37.5 cm and 1.1 kg — roughly an aubergine — with a sleep-wake rhythm of their own now, one that frequently does not match yours. This is also the week kick counts genuinely start to matter as a way of checking in between appointments.
The short answer: baby has developed a real sleep-wake cycle, eyelashes are fully grown, and antibodies are starting to cross the placenta from you, an early layer of protection for after birth. For you, movements may feel slower as space tightens, relaxin loosens the pelvic joints enough to cause a "duck walk," and this is often the week a repeat blood count and, if you're RhD-negative, anti-D prophylaxis are offered.
Your baby this week
Baby has settled into a genuine sleep-wake schedule now, distinct periods of activity and rest that often run on their own timing rather than yours — which is part of why a burst of movement can wake you at night while daytime feels quieter. Eyelashes are fully grown, and hair on the head continues to thicken for those who have it, though the amount at this stage says nothing about how much hair baby will have long-term.
The immune system has started receiving antibodies from you across the placenta, a passive transfer that continues through the rest of pregnancy and gives baby a first layer of protection against infections in the weeks right after birth, before their own immune system has had time to build its own defences.
Your body this week
Movements may feel slower now, less the sharp jabs of a few weeks ago and more of a rolling, stretching sensation as space in the uterus tightens. This is a change in character, not necessarily frequency — which is exactly why tracking the pattern rather than the sensation alone becomes useful from here. The hormone relaxin continues loosening the ligaments around the pelvic joints, which can make them feel less stable and produce a slightly waddling walk some describe as a "duck walk," especially noticeable getting in and out of a car.
A repeat full blood count and antibody screen are commonly done around now, and if your blood type is RhD-negative, routine antenatal anti-D immunoglobulin is typically offered at this point as a preventive measure, not a response to any detected issue.
Tests and appointments
Tests and scans around now: Repeat full blood count and antibody screen. If you are RhD negative, anti-D prophylaxis is usually given from 28 weeks.
Exact timing varies by country and by your own care plan — your doctor or midwife will confirm the schedule that applies to you.
This is also the week many care pathways start counting daily kick sessions as part of the routine, since baby's movement pattern is now established enough to be a genuinely useful signal to track.
✅ Worth doing this week
- Start daily kick counts — pick a time baby is usually active and note how long 10 movements take
- Ask about anti-D at your next appointment if you know or suspect you are RhD-negative
- Try a pelvic support belt if the "duck walk" feeling is uncomfortable
- Use compression stockings and elevate tired legs when you can
- Learn baby's usual pattern now, while it is easier to notice a genuine change later
When to call your doctor
Call the same day if: movement feels clearly reduced or different from baby's usual pattern, especially fewer than 10 movements in 2 hours during an active period — do not wait to see if it picks up. Also call for bleeding, a severe headache with visual disturbance, sudden swelling of the face or hands, regular tightenings before 37 weeks, or a temperature above 38°C.
FAQ — 28 weeks pregnant
Why do kick counts matter starting at 28 weeks?
By the third trimester, movement patterns become established enough to track meaningfully, and a baby's usual pattern is one of the most reliable signals available between appointments. The standard guidance is at least 10 movements within 2 hours during a time baby is normally active — fewer than that, or a pattern that feels clearly different from usual, is worth calling about rather than waiting to see if it changes.
What is anti-D and why is it given at 28 weeks?
Anti-D immunoglobulin is offered to pregnant people with RhD-negative blood to prevent their immune system from forming antibodies against the baby's blood cells if the baby is RhD-positive, which can matter in this or a future pregnancy. Routine antenatal anti-D prophylaxis is commonly given around 28 weeks, alongside a repeat blood count and antibody screen — it is a preventive dose, not a response to a detected problem.
What is the "duck walk" some people describe at 28 weeks?
It refers to a slightly waddling gait that can develop as the hormone relaxin loosens the ligaments around the pelvic joints in preparation for birth, sometimes making the joints feel less stable and walking a little more effortful. It is common and not harmful, though a pelvic support belt and being mindful of movements like getting out of a car can ease the discomfort.
How big is the baby at 28 weeks?
Around 37.5 cm and 1.1 kg — roughly an aubergine. Eyelashes are now fully grown, hair on the head keeps thickening, and the immune system has started receiving antibodies from the mother through the placenta, an early layer of protection baby will rely on after birth.
Week 28 at a glance
At 28 weeks your baby is around 37.5 cm and 1.1 kg, with a sleep-wake cycle of their own, fully grown eyelashes, and antibodies now crossing the placenta from you. For you, movements shift in character as space tightens, relaxin loosens the pelvic joints enough to change your walk, and this is often the week a repeat blood count and anti-D prophylaxis, if needed, are offered — alongside the start of daily kick counting as a genuinely useful habit.
Inside Baby Novum: the kick counter times each session and keeps a history, so a slower day compared with baby's usual pattern is something you can check against real data rather than guess at.