Last week your baby's eyelids were sealed but already sensitive to light. This week, a new sense comes online: hearing. The tiny bones of the inner ear — the smallest bones in the human body — are now sufficiently developed for your baby to detect sound. What they hear is muffled, low-pitched, and filtered through layers of fluid and tissue, but it is real. They can hear your voice. They can hear your heartbeat — the sound that has been constant since the earliest weeks. They can hear your digestion, the traffic outside, music, the sound of your partner talking nearby.
The baby has reached 116mm — an avocado — and has crossed the 100g threshold. The body proportions are now recognisably human: the limbs are in proportion to the torso, the neck is fully extended, and the facial features are distinctly individual. The eyes, still sealed, are pointing forward. The ears are in their final position on the sides of the head. On a scan, the baby looks recognisably like a baby rather than an abstraction.
Eyebrows and eyelashes are beginning to develop this week — fine hairs growing in the follicles above and around the eyes. The unique pattern of these features — like the fingerprints — will be entirely this baby's own. Facial expressions are now more frequent and varied: the foetus frowns, squints, makes what appears to be a smile. These are not conscious expressions; they are the muscles practising the full range of movement they will need.
I didn't feel anything at sixteen weeks but I started singing to them anyway, because I'd read that they could hear. Just songs I knew. It felt slightly ridiculous at first. By the time they were born it felt completely natural. And the midwife said she could already hear them responding to my voice on the monitor. I'm so glad I started early.
Quickening — the first time you feel your baby move — is one of the most significant moments in pregnancy. For most first-time parents it happens between weeks 16 and 22. For those who have been pregnant before, it often arrives earlier, around weeks 14–16, because they know what to recognise. Week 16 is the start of the window when quickening commonly arrives for second-time parents, and sometimes, for perceptive first-timers, the very first faint hints.
What it is not, at this stage: kicks, punches, or the assertive rolling movements of the third trimester. Those come later. What you are feeling now is a tiny being, about the size of an avocado, turning and flexing in a fluid-filled sac. It is subtle. It is unmistakable once you know it.
If you haven't felt anything by week 16, this is not a cause for concern. The timing of first movements varies considerably between pregnancies and between individuals. The position of the placenta plays a role: an anterior placenta (one that sits at the front of the uterus, between the baby and the abdominal wall) acts as a cushion and significantly dampens the sensation of early movement. If you have an anterior placenta — which will have been visible at the 12-week scan — you may not feel movements clearly until weeks 18–22.
I felt the first flutter at exactly sixteen weeks, lying in bed, and I immediately thought it was indigestion. Twenty minutes later it happened again, in the same place, the same sensation. Too regular for digestion. I lay completely still and waited. And then it happened a third time. I woke my partner up. We both cried.
The physical experience of week 16 continues the positive direction of recent weeks, with a few specific developments worth naming. The bump, for most people, is now clearly visible — not necessarily to strangers or in winter clothing, but unmistakably present in a mirror or in fitted clothes. This often marks a shift in how the pregnancy is experienced from the outside: people begin to notice, to comment, to offer seats on public transport. The pregnancy enters a new phase of social visibility.
Back pain — as the uterus grows, the centre of gravity shifts forward, putting more strain on the lower back. Pregnancy-appropriate exercise (particularly swimming and pregnancy yoga), good posture, and supportive footwear all help. If back pain is significant, ask your midwife about a physiotherapy referral — available on the NHS, and highly effective.
Skin sensitivity — some people notice that the skin on the abdomen begins to feel tight or sensitive as it stretches. Keeping skin moisturised helps with comfort; whether it affects stretch marks (which are largely genetic) is less clear, but the ritual is not harmful and many people find it a meaningful physical connection to the bump.
The 16-week appointment typically falls around this week. Blood pressure and urine are checked, the anomaly scan is booked (if not already), and your midwife may offer to listen to the heartbeat with a hand-held Doppler. If they don't offer and you would like to hear it, ask. The first time you hear that rapid, definite rhythm — around 140–160 beats per minute — is its own significant moment.
Week 16 tends to be one of the emotional peaks of the second trimester — not because anything dramatic happens on a fixed schedule, but because of what it contains: possible first movements, audible heartbeat, visible bump, the beginning of the baby being able to hear you. Any one of those things would be significant; together, they can make this week feel like a threshold — the pregnancy becoming, unmistakably, a person.
If quickening hasn't arrived yet, there can be an impatience to week 16 — a watching and waiting that is very different from the anxiety of the first trimester. It is anticipation rather than dread. You know, from the scans, from the heartbeat, that the baby is there and moving. You are simply waiting for the connection to become physical. That waiting is its own form of intimacy.
Sixteen weeks was when it stopped feeling like something happening to me and started feeling like a relationship. Not just a pregnancy — a person. Someone I was already in a relationship with, who could already hear me. That shift was quiet but complete.
The anomaly scan — now approaching — may begin to take up more emotional space. Unlike the first trimester scan, which was primarily anticipated with relief, the anomaly scan carries a different weight: it is the detailed structural check, the one that can identify more significant findings, and — for many people — the one where the sex becomes visible. Both the hope and the complexity of that appointment deserve to be acknowledged in advance rather than arrived at unprepared.
Week 16 connects directly to these full topic guides.
Week 16 is often the point at which partners describe the most significant shift in their engagement with the pregnancy. The baby can now hear — including your voice. If there has been any reticence about talking to the bump, singing to it, or acknowledging it as a listening presence, this is the week that context changes. You are not performing for an imagined audience. You are actually being heard.
The first movements — if they arrive this week — change things for partners too, though partners typically cannot feel quickening from the outside yet. That will come in the weeks ahead. For now, if your partner feels a flutter, share in the significance of it even if you can't feel it yourself. Ask them to describe it. Let it matter. This is the beginning of a physical relationship between your partner and the baby that you will be included in more and more over the coming weeks.
- Start talking to the bump. It is not too early, and it is not performative. Your baby can hear muffled voices from outside the womb and will recognise yours at birth. Speaking, reading, singing — all of it is meaningful from this point.
- Attend the 16-week appointment if you can. The heartbeat check is often the single moment partners identify as their clearest point of emotional arrival in the pregnancy. Being there for it matters.
- Discuss the anomaly scan. It is four weeks away. Do you want to find out the sex? What will you do if the scan identifies something that requires follow-up? Simple conversations now prevent panicked decisions in the moment.
Start a movement diary. Not because you need to be monitoring foetal movement this week — formal kick counting is recommended from around week 24 — but because beginning to notice and record the movements now, while they are new and still infrequent, builds the awareness and baseline understanding that becomes important later. Knowing your baby's individual pattern of activity, their busy times and quiet times, makes any future concern easier to assess.
The WiseMama diary is an ideal place for this — a brief note each day of when you noticed movement, what it felt like, and what you were doing. This is not medical monitoring; it is the beginning of paying attention to a specific person with their own rhythms. The notes you write now are also, simply, a record of the beginning of knowing them.
At the 16-week appointment, alongside asking about the anomaly scan booking, raise this:
Knowing whether you have an anterior placenta — and understanding that this typically delays and dampens the sensation of early movement — prevents weeks of unnecessary anxiety when quickening doesn't arrive on the schedule other people suggest. It is a simple question with a specific, useful answer.