Week 39 is when most women go into labour within a week either side of their due date. Waters can break at any time, and almost never the way films show it. What is worth knowing precisely this week is when to pick up the phone.
Your body this week
More discharge is usual, and it should be thin, white and without much smell. A show — a slimy blob of mucus, sometimes yellow or bloodstained — is the plug that sealed the cervix coming away. It can mean labour is coming and it can still be days off.
Back pain often increases as the head presses against the spine, and there is more pressure at the bottom of the bump. Sudden bursts of energy and an urge to tidy are the nesting instinct.
On waters breaking, the NHS is specific: do not expect a tidal wave — it may be a trickle. If you think it has happened, call your midwife or maternity unit for advice, because once waters have broken there is a greater risk of infection and your care may change.
What you may notice
Practice contractions can be frequent now. The NHS's threshold for calling is clear: phone the hospital or midwife when contractions last at least 60 seconds and come every five minutes — or at any time if something worries you, such as movements stopping or any bleeding.
Also expect: sleep problems, backache, piles, indigestion and heartburn, leg cramps, swelling, dizziness, and everything else the third trimester has been offering for weeks.
Your baby this week
Around week 39, the length quoted is about 50.7cm from head to heel — the NHS compares it to a small watermelon. These are averages describing many pregnancies, not a measurement of one.
The skin has grown a tougher outer layer that protects and helps with temperature. The waxy vernix coating may still be there at birth or may be mostly gone, and both are ordinary.
What care usually happens around now
Nothing is routinely scheduled for most women this week, and appointments resume at 40 and 41 weeks in the UK for a first baby.
Two lists are worth reading before the birth rather than after. The NHS names nine signs that should be treated as an emergency at this stage: any bleeding, brown or pink discharge, severe itching particularly at night, a headache that will not go, vision problems, pain just below the ribs, extreme swelling of the feet, ankles, hands and face, persistent stomach pains, and a temperature above 37.5C with no cold or flu symptoms. The second list is what a newborn is actually like in the first minutes — often quiet before crying, blue hands and feet, irregular breathing — because knowing that in advance prevents a great deal of fright.
This week's tip
Agree with your birth partner tonight who calls the unit and who drives. It sounds absurdly small. It is the thing that reliably falls apart at 3am, and the version where both of you already know the answer is the version that works.
When to see a doctor
Call your maternity unit when contractions last 60 seconds and come every five minutes, or at any time if waters break, movements change, or you have bleeding. Pregnancy warning signs has the full list.
Seek care now: Contact your local emergency services or go to your nearest emergency department if you have heavy bleeding, severe or one-sided tummy pain, pain just below the ribs, a severe headache with vision changes, sudden swelling of the face or hands, a fever, fluid leaking from the vagina, chest pain, trouble breathing, fainting, or a seizure. Contact your maternity service the same day for any reduction in your baby's usual pattern of movement. Femio cannot assess a pregnancy.
Frequently asked questions
How do I know if my waters have broken?
You often cannot be certain, which is why the advice is to call and be assessed rather than to work it out at home. It may be a trickle rather than a gush.
When exactly should I go in?
The usual guidance is contractions lasting 60 seconds coming every five minutes, and any time you are worried. Week 40 covers the due date and beyond, and week 38 covers the induction conversation.