28 weeks pregnant

How big is your baby at 28 weeks?

About the size of an aubergine — around 37.6 cm (14.8 in) long head to heel, according to the NHS, weighing roughly 1,189 g (2 lb 10 oz).

From here your baby roughly triples in weight before birth.

A note on the numbers: from week 20 the NHS measures head to heel, not head to bottom. Weights here are the median of the WHO fetal growth charts — half of babies weigh more, half less, and a scan estimate can be out by 10 to 15 per cent either way. A number below the median is not a diagnosis.

What's developing this week

The heart rate has settled. The NHS traces the arc: around 110 beats per minute when first detectable at 5 or 6 weeks, about 170 by weeks 9 and 10, around 140 now, and about 130 at birth. Small hearts cannot pump much per beat, so they beat faster. The heartbeat can now be heard through a stethoscope.

What you might feel

Heartburn, a back under strain, looser joints, and puffy ankles, feet and face, especially in hot weather. The NHS makes a specific point about that swelling: get it checked, because pre-eclampsia can leave you feeling perfectly well while your blood pressure climbs fast.

Nosebleeds are common now and can happen in your sleep. Sit or stand rather than lying down, pinch above the nostrils for 10 to 15 minutes and lean forward.

Movements from 28 weeks: the response tightens

The advice does not change, but what happens when you report a change does. The RCOG sets out three tiers by gestation, and from 28 weeks you are in the top one: contact your maternity unit immediately, and expect a full antenatal check plus at least 20 minutes of heart-rate monitoring, with a scan within 24 hours if your bump measures small or monitoring is normal but movements still feel reduced.

There is no target number of movements: the NHS is explicit that you do not need to count kicks. What matters is your baby's usual pattern, and calling immediately if it reduces, weakens or changes. Our kick counter describes a pattern; it does not score one.

Is 28 weeks pregnant 6 months or 7 months?

Week 28 is the first week of month 7, and the first week of the third trimester on the NHS calendar.

There is no official weeks-to-months map. A calendar month averages about 4.3 weeks, not 4, so 40 weeks is a little over nine months, and two apps can disagree. The most widely used mapping:

• Month 1 — weeks 1 to 4
• Month 2 — weeks 5 to 8
• Month 3 — weeks 9 to 13
• Month 4 — weeks 14 to 17
• Month 5 — weeks 18 to 22
• Month 6 — weeks 23 to 27
• Month 7 — weeks 28 to 31
• Month 8 — weeks 32 to 35
• Month 9 — weeks 36 to 40

Your maternity team will not use months. Everything is booked by week and day — "28 weeks and 3 days" — because a few days change what is offered.

What's happening at your appointments around now

The 28-week appointment is the densest of the second half of pregnancy, and everyone gets one. NICE guideline NG201 sets the content: a blood test for full blood count, blood group and antibodies, plus anti-D prophylaxis for RhD-negative women not already sensitised. The NHS adds blood pressure, urine, a bump measurement, a conversation about movements and mental health, and labour information.

Anti-D, by country

If you are RhD negative and your baby may be RhD positive, you can make antibodies against your baby's red cells — usually harmless in a first pregnancy, potentially serious in a later one. Anti-D immunoglobulin prevents them forming. Timing differs:

• UK — NICE NG201 puts routine antenatal anti-D at the 28-week appointment, in line with NICE technology appraisal TA156.
• Australia and New Zealand — RANZCOG recommends 625 IU at approximately 28 weeks and again at approximately 34 weeks.
• United States — ACOG describes Rh immunoglobulin at 28 weeks, and again within 72 hours of birth if the baby is RhD positive.

Every schedule also gives anti-D after bleeding, abdominal trauma, amniocentesis or an attempt to turn a breech baby. If you are RhD negative and bleed from now on, say so when you call.

Vaccines land this week too

In the UK the RSV vaccine is offered from 28 weeks, around this appointment; ACOG's US timing is 32 0/7 to 36 6/7 weeks, seasonally. Whooping cough differs too: the UK offers it from 16 weeks and asks for it before 32; RANZCOG recommends dTpa preferably between 20 and 32 weeks; ACOG recommends Tdap between 27 and 36 weeks. If you are reading advice written for another country, check the week numbers first.

Gestational diabetes testing closes this week in the UK and the US.

Is it safe to fly at 28 weeks pregnant?

Medically, yes, in a straightforward pregnancy — the RCOG position has not changed. Practically, this is where travel gets complicated: ACOG says the best window is 14 to 28 weeks, and after that travel may be riskier.

Keep two things apart. The medical position is the RCOG's: the safest time to fly is before 37 weeks with one baby and before 32 weeks with uncomplicated twins, because from those points labour becomes likely. The airline position is a commercial rule — most carriers refuse you after 37 weeks, some set an earlier limit, and from 28 weeks most want a letter from your midwife or doctor, which the NHS warns can cost money and take weeks. An airline rule is not medical advice.

The risk that is real: blood clots

ACOG puts it plainly: any travel of four hours or more — car, train, bus or plane — doubles DVT risk, and pregnancy adds to that. Under four hours the RCOG says you are unlikely to need special measures. Over four hours:

• Loose clothing, an aisle seat, regular walks about the cabin
• In-seat exercises roughly every 30 minutes, and water steadily
• Graduated compression stockings sized for you by a midwife or doctor — ACOG warns that stockings which are too tight or worn wrongly increase the risk instead

Practical points

• Ask for the fitness-to-fly letter at this appointment.
• Check what maternity and neonatal care exists at your destination, and carry your maternity notes.
• Tell your insurer you are pregnant. The NHS says cover should include care in labour, premature birth and the cost of changing your return date.
• Travel to Zika areas is not recommended; some travel vaccines and anti-malarials are unsuitable.

When to call your midwife or doctor

Maternity units are staffed 24 hours a day, and away from home you can walk into any of them.

Get emergency help now

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand) or go to an emergency department if you have:

• Heavy vaginal bleeding, or bleeding with severe abdominal pain
• Abdominal pain you cannot concentrate through
• Fainting or collapse, chest pain, or sudden breathlessness
• A severe headache painkillers do not touch, blurred vision or flashing lights, pain below your ribs, vomiting, or sudden swelling of your face, hands or feet — NHS and ACOG both list these as pre-eclampsia symptoms needing immediate assessment
• Pain, swelling or heat in one calf or thigh, which can be a DVT

Call your midwife or maternity unit today, whatever the hour

• Any reduction, weakening or change in your baby's usual pattern of movements. Call immediately, not in the morning, and do not use a home doppler — hearing a heartbeat does not mean your baby is well
• Regular tightenings, period-type pains, or backache that is not usual for you — the NHS list for possible premature labour, meaning labour before 37 weeks, which affects about 8 in every 100 babies
• A gush or a trickle of fluid, which could be your waters breaking
• Any vaginal bleeding, however light
• Itching without a rash, especially at night or on your palms and soles — it can be intrahepatic cholestasis of pregnancy
• A temperature, feeling generally unwell, or burning when you pee
• If you are RhD negative and have any bleeding, mention it when you call — you may need an extra anti-D dose

You do not need to be certain something is wrong. That is what the number is for.