By Anna Cave-Bigley

At six weeks everybody told me I was doing brilliantly. I was awake before the baby, the house was in order, I was answering emails nobody had sent me. I looked like a woman coping. I now know I already had postnatal depression and had done for weeks.

What I did not have yet was the flatness. That arrived at five months, when the wired feeling burned off and left nothing behind it. Same illness, different shape, and only then did it look like anything a doctor would recognise. Month five was the worst I felt in the entire year, and it was also the month by which everybody had decided I was through the hard bit.

What I know now is that months four to six are a documented pile-up. Sleep debt, a hormonal cliff, a thyroid gland that goes wrong in a predictable window, iron on the floor, and a support system that packed up without telling you. Here is what is happening in your body around now, what to rule out before you accept feeling like this, and how to tell an awful few weeks from something that needs treating.

The myth of the worst part

The cultural script says the first six weeks are the hardest and it gets easier from there. For a lot of women that is not how it goes.

The early weeks run on acute stress hormones. Adrenaline and cortisol are high, everything is novel, and there is usually somebody in the house. Acute deprivation is survivable in a way that chronic deprivation is not. By month five the adrenaline has gone, the novelty has gone, the help has gone, and you are still not sleeping.

You have not got worse at this. The conditions changed.

Sleep debt accumulates

By five months you have had roughly a hundred and fifty broken nights. Sleep loss does not reset with one good night, and the effects compound.

The four-month sleep regression is real and it lands squarely in this window. Around then a baby's sleep architecture matures into adult-like cycles with more frequent surfacing between them. Babies who slept in long newborn stretches start waking every couple of hours. For many women, the worst sleep of the entire postpartum year happens at four to five months, not at two weeks.

Chronic sleep restriction affects mood regulation, glucose handling, appetite and immune function. It is also one of the strongest predictors of postnatal depression in the research, which matters because it makes sleep a clinical issue and not a lifestyle complaint.

The hormonal cliff

Three things tend to shift at once around now.

Prolactin starts falling. As solids come in and feeds reduce, prolactin declines. Prolactin is not only about milk. It has a calming, anti-anxiety effect, and the drop removes a buffer you have been running on for months without knowing it. Women who night wean in this window sometimes describe a mood drop within days.

Oxytocin drops with feeds. Fewer feeds means fewer oxytocin surges across the day. For some women the reduction is felt as low mood or a flat, tearful few weeks, particularly during active weaning.

Ovarian activity restarts. Oestrogen and progesterone have been either very high or very suppressed for well over a year. When cycling resumes, often somewhere between five and eleven months in breastfeeding women, you get fluctuation again, and the first cycles are frequently irregular with a short luteal phase. Women who were sensitive to premenstrual mood changes before pregnancy often find the sensitivity returns amplified.

The one to rule out: your thyroid

If you read nothing else here, read this.

Postpartum thyroiditis affects somewhere between five and nine per cent of women, which makes it common. It typically runs in two phases. A transient overactive phase in the first one to four months, often mistaken for anxiety. Then an underactive phase, usually between four and eight months postpartum, which is precisely the window this article is about.

The hypothyroid phase looks like this: exhaustion that sleep does not touch, low mood, brain fog, feeling cold, hair loss, dry skin, constipation, weight that will not move. Read that list again and notice that every single symptom is also on the postnatal depression list.

This is the most misdiagnosed thing in postpartum medicine. Women are handed antidepressants for a thyroid problem, or told they are depressed when their TSH would have answered the question in one blood test. Risk is higher if you have type 1 diabetes, a personal or family history of thyroid disease, or positive thyroid antibodies.

Ask for thyroid function tests, TSH and free T4, and ask for thyroid antibodies if the first results are borderline. If you are told you are within range, ask for the actual numbers. Most cases resolve within twelve to eighteen months, but a meaningful proportion go on to permanent hypothyroidism, so this is worth following up rather than shrugging off.

Iron, and everything else you spent

You built a person, lost blood delivering them, and have spent months feeding them from your own stores. Ferritin often bottoms out months after birth, not at birth.

Iron deficiency without anaemia is the version that gets missed. Your haemoglobin comes back normal, you are told your bloods are fine, and your ferritin was never measured. Symptoms are fatigue, breathlessness on stairs, poor concentration, low mood and hair loss.

Ask for ferritin specifically. Vitamin D, B12 and folate are worth having on the same form. If you are still breastfeeding, your omega-3 stores have also been drawn down, since DHA is preferentially transferred to the baby.

None of this is exotic and all of it is testable. Do not accept feeling like this until somebody has looked.

It may already have been there

Two things get missed here and they are worth separating.

The first is that postnatal depression does not always look like sadness, and in the early weeks it very often does not. It shows up as anxiety, agitation, hypervigilance, an inability to sit down, checking the baby compulsively, and lying awake wired while exhausted. Outwardly that reads as a woman on top of things. It reads that way to her family, to her GP, and to her.

Then somewhere around month four or five the arousal burns off and the same illness presents as flatness. No pleasure in anything, no energy, no interest. That is usually the point at which it becomes legible as depression, which is why so many women date their PND to the fifth month when it started months earlier.

I am one of them. At six weeks I filled in the questionnaire and did not lie on a single line, because the questions were about sadness and I was not sad. I was wired. Nobody was screening for that, including me.

The second thing is that genuine late onset also happens. Diagnostic criteria have historically framed postnatal depression as beginning within four to six weeks of birth, and screening in most countries is built around that assumption. Onset at four, five and six months is well documented, and by then you are outside the system. Health visitor contact has tapered. The GP is seeing the baby.

Either way, the conclusion is the same. If it started later than the leaflet said it should, or if it was there all along wearing a different face, it still counts and you are still entitled to help.

Then everything else stops

The practical collapse is as real as the biochemical one, and it happens on almost exactly the same schedule.

Visitors stop around week six. Partners return to work. Meals stop arriving. In the UK, maternity leave is either ending or close enough to end that you are thinking about childcare and money. The person who asked how you were every day has gone back to their own life.

Meanwhile the baby is more demanding, not less. They are awake for longer, moving, needing watching. The load goes up as the support goes down, and you meet the crossover somewhere around month five.

How to tell a bad stretch from depression

Everybody has awful weeks. The distinction that matters is not intensity but shape.

A bad stretch responds to conditions. One decent night, a morning to yourself, a break, and you feel some relief, even briefly. You can still be moved by things. You get glimpses.

Depression does not lift when the conditions improve. The features to take seriously are anhedonia, meaning nothing brings pleasure including the things that reliably used to, persistent hopelessness, feeling detached from your baby, guilt that will not respond to reassurance, sleeping badly even when the baby sleeps, and intrusive thoughts. If any of that lasts more than two weeks, that is the threshold. Go to your GP.

Two things to know about intrusive thoughts, because they keep women silent for months. Unwanted, distressing thoughts about harm coming to the baby are extremely common in the postpartum period and are not a sign you are dangerous. Being frightened by the thought is the point. But say them out loud to a professional, because they are treatable and because keeping them secret is what makes them grow.

If you are having thoughts of harming yourself or your baby, or you feel confused, paranoid or unlike yourself in a way that frightens the people around you, treat that as urgent and seek help the same day.

What actually helps

I am wary of writing a list here, because a woman in the fifth month does not need another set of instructions she cannot complete.

So, in order. Get bloods done: thyroid, ferritin, B12, vitamin D. Sleep is medicine and someone else needs to take a night, which is a conversation with your partner or your mother or whoever you have, and it is not a favour. Eat properly and eat protein, because months of grazing on whatever is nearest has a cost. Get outside daily, ideally early, for the light rather than the exercise. Tell one person the truth about how bad it is.

And go to your GP if it has been more than two weeks. Not to be brave about it. The gap in postnatal care is real and you have to be the one who closes it, which is unfair and also true.

Where a ritual fits

None of this is fixed by a tea and I am not going to pretend otherwise. What a ritual does is smaller. It marks a boundary in a day that has none.

The Calm is built around lemon balm, passionflower and chamomile, among the most studied botanicals for emotional support and long used to soothe. It is what I made at nine in the evening when the house finally went quiet, less for the plants than for the ten minutes. If you are still feeding, Mama Recover is formulated for the postpartum months and suitable while breastfeeding.

Neither is a treatment for depression. If that is what this is, you need your GP, and the tea can wait until after the appointment.

What I would tell myself

That being wired is not the same as being well. That looking like you are coping is not evidence, and that I gave everybody around me a very convincing performance for four months without meaning to.

That the fifth month is a known pile-up and not a personal failing. And that saying it out loud to my GP, eventually, took about eleven minutes and changed the whole year.

When to get help now

Contact your GP, midwife or health visitor if low mood, anxiety or exhaustion has lasted more than two weeks. Seek same-day help if you have thoughts of harming yourself or your baby, if you feel confused or detached from reality, or if those around you are frightened by how you seem. In the UK you can also contact Samaritans on 116 123 at any hour, or PANDAS for perinatal mental health support.

References

1. Stagnaro-Green A. Postpartum thyroiditis. Best Pract Res Clin Endocrinol Metab, 2004.

2. Alexander EK, et al. Guidelines for the diagnosis and management of thyroid disease during pregnancy and the postpartum. Thyroid, 2017.

3. Wisner KL, et al. Onset timing, thoughts of self-harm, and diagnoses in postpartum women with screen-positive depression findings. JAMA Psychiatry, 2013.

4. Okun ML. Sleep and postpartum depression. Curr Opin Psychiatry, 2015.

5. Milman N. Postpartum anaemia: prevalence and treatment. Ann Hematol, 2011.

6. Mills J, et al. Sleep architecture changes in infancy across the first year.

7. Torner L, Neumann ID. The brain prolactin system: involvement in stress response adaptations in lactation. Stress, 2002.

8. National Institute for Health and Care Excellence. Antenatal and postnatal mental health guidance, CG192.

ABOUT ANNA

Anna is a Co-Founder of The SABI and has spent the past 13 years working in or for governments, senior businessmen and politicians around the world. Living in Bogota, Colombia, she recently renovated one of Colombia's oldest and most iconic coffee estates, developing a unique taste and travel experience. She lives with her husband and three boys Lorenzo, Alfie and Salvador who are responsible for the beautiful journey that inspired her to pursue The SABI.

HORMONAL & PROUD

The SABI was created to help women through the hardest moments of pregnancy, childbirth, postpartum and every stage that follows. We want to change the story around our hormones, from one of taboo, embarrassment and loneliness to one of awareness, and even pride.

More than a wellness brand, The SABI is a line of rituals, supportive tools and functional herbal remedies, tested by hundreds of years of traditional medicine and now backed by modern science. It was conceived by women who have lived the joys and the deeper costs of bringing a child into the world, of a heavy or difficult period, of miscarriage and trouble conceiving.

Consider this an invitation to know your body and its cycles, to learn to work with them at any stage of life, and to know that support exists. Look for the right sources, know there is help, and know that you are not on your own.

DISCLAIMER

The SABI blog and articles are not meant to instruct or advise on medical or health conditions, but to inform. The information and opinions presented here do not substitute professional medical advice or consultations with healthcare professionals for your unique situation.