The first trimester was survival. Nausea, exhaustion, secrecy, and the constant low hum of anxiety that something might go wrong. If you have made it to week 13, the risk drops significantly, and for many couples a weight lifts.
The second trimester, weeks 13 to 27, is often called the golden trimester. She usually feels better. The nausea fades. Energy returns. The bump starts to show. And somewhere around week 20, the pregnancy stops being abstract and becomes real: you see your baby on the anatomy scan, you feel the first kick from the outside, and the countdown starts ticking in a way that changes your brain.
This is also the window where you have time and energy to prepare. The third trimester will be uncomfortable and rushed. The second trimester is where calm, organised dads get ahead. Here is how to use it.
If you missed it, start with the first trimester partner guide. When you are done here, the third trimester guide picks up from week 28.
What is happening to her: weeks 13 to 27
Weeks 13 to 16: the fog lifts
For many women, this is the best part of pregnancy. The nausea fades or disappears. Energy returns to something approaching normal. The hormonal rollercoaster of the first trimester levels out. She may feel genuinely good for the first time in months.
The bump starts appearing, though at this stage it often looks more like a big lunch than a baby. Some women show early, some not until well into the second trimester. This is entirely down to body type, core muscle strength, and whether it is a first or subsequent pregnancy.
She may start feeling very faint flutters, sometimes described as bubbles or butterflies. These are quickening: the first baby movements. They are too light for you to feel from the outside yet, but for her this is a landmark moment.
Weeks 16 to 20: the anatomy scan approaches
The bump is more obvious. She may need maternity clothes. Her appetite returns, sometimes with force. Cravings can be specific and intense. Mood tends to be more stable than the first trimester, though hormonal shifts still cause occasional emotional days.
Physically, she may notice skin changes: a dark line down the belly (linea nigra), darker nipples, patches of pigmentation on the face. These are hormonal and usually fade after birth. Round ligament pain can start: sharp twinges on the sides of the bump when she moves suddenly. Normal but uncomfortable.
Weeks 20 to 24: the anatomy scan and first kicks
The 20-week anomaly scan is the big one. More on that below. Around this time, movements become strong enough that you can feel them from the outside. The first time you put your hand on her bump and feel a definite kick is one of those moments you will remember. It makes the whole thing real in a way that nothing else has so far.
Her body is working hard. Blood volume increases by about 40 percent during pregnancy, mostly in the second trimester. This can cause dizziness, especially when standing up quickly. She may feel warmer than usual. Nasal congestion is surprisingly common (pregnancy rhinitis) because the increased blood flow swells the nasal membranes.
Weeks 24 to 27: the home stretch of the middle
The bump is now unmistakable. She may start finding sleep uncomfortable as she cannot lie on her back (the weight of the baby can compress the vena cava, reducing blood flow). Side sleeping with a pregnancy pillow becomes the default. Back pain may begin. Braxton Hicks contractions, the practice tightenings, can start appearing from mid-second trimester onwards.
Week 24 is a significant milestone: it is the point of viability. If the baby were born now, there would be a realistic chance of survival with neonatal intensive care. Nobody wants to think about this, but it is a reassuring line to cross.
The 20-week anatomy scan: what dads need to know
This is not like the dating scan at 12 weeks. That was a quick check on size and due date. The 20-week scan is a full anatomical survey. The sonographer checks:
- Brain structure and head shape
- Spine alignment
- Heart chambers and blood flow
- Stomach, kidneys, and bladder
- Arms, legs, hands, and feet
- Placenta position
- Amniotic fluid levels
- Umbilical cord
It takes 20 to 30 minutes and is thorough. The sonographer is concentrating. Long silences during the scan do not mean something is wrong. They are working through a checklist.
Finding out the sex
If you want to find out, tell the sonographer before they start. Some hospitals have a policy of not revealing the sex, so check in advance. If they do, accuracy at 20 weeks is around 95 to 99 percent, but it depends on the baby's position. If the legs are crossed at the wrong moment, they may not be able to tell.
The "should we find out?" conversation is worth having properly rather than just going with the flow. About 60 percent of UK parents choose to find out. Neither choice is better. What matters is that you agree.
If something is flagged
In about 1 in 20 scans, the sonographer finds something that needs further investigation. This does not necessarily mean something is wrong. It often means they need a better angle, a specialist scan, or a follow-up to check something that was unclear. Soft markers (minor findings that slightly raise statistical risk but resolve on their own) are relatively common and cause a lot of unnecessary anxiety. If something is flagged, ask: "What is the next step?" Focus on the process, not the panic.
Go to this scan. This is not optional-attendance. You see your baby's face, watch the heart beating, and hear the sonographer confirm that everything is developing normally. If something is found, you need to be there to hear it together and process it together. Book the time off work. This one matters.
What she needs from you in the second trimester
The second trimester is a different kind of support than the first. She is feeling better, so the daily survival help (covering meals, handling her nausea) eases. What replaces it is more operational and emotional.
Be present, not just available
The temptation when she feels better is to slip back into your own routine. Work picks up, social life returns, the urgency of the first trimester fades. Resist this. She needs you present at scans, engaged in decisions about the baby, and interested in how the pregnancy is progressing. "How are you feeling?" asked genuinely, not reflexively, once a day is better than a grand gesture once a month.
Start the big conversations
The second trimester is the time to discuss the things you will need to have agreed before the baby arrives. Not all at once. But in manageable pieces over the weeks:
- Feeding: Is she planning to breastfeed, formula feed, or see how it goes? What is your role in supporting whichever choice? See our breastfeeding support for dads guide.
- Sleep arrangements: Bedside crib, Moses basket, or separate room? The Lullaby Trust and NHS recommend room-sharing for at least the first 6 months. See our safe sleep guide.
- Childcare: If you both work, when does she go back and what does childcare look like? Nursery waiting lists in popular areas can be 6 to 12 months long. Start looking now.
- Finances: Run the numbers on maternity and paternity pay. What does the household income look like for the first year? What changes need to happen?
- Parental leave: How much paternity leave are you taking? Can you take shared parental leave? What does your employer offer beyond the statutory minimum?
- Names: Start a shortlist. This is more fun than the financial conversations.
Take the initiative on practical prep
The second trimester is the best time to start tackling the logistical list. She has energy, you have time, and nothing is urgent yet. But if you leave it all to the third trimester, you will be competing with exhaustion, appointments, and the growing sense that the baby could arrive at any time.
- Research the big purchases: car seat, pram, cot. Read reviews, compare options, and bring her shortlisted choices rather than asking her to start from scratch.
- Book antenatal classes: NHS classes are free but fill up fast. NCT courses need booking months in advance. See what is available locally and book before 24 weeks for classes that run at 30 to 36 weeks.
- Start the nursery (or sleeping area): Clear the room, paint if needed, order the cot. You do not need to finish it now, but getting the structural work done while the house is calm is much easier than doing it with a 38-week pregnant partner and a two-week deadline.
- Sort your paperwork: Review your life insurance, update your will if you have one (or make one: you are about to have a dependent), check your employer's paternity leave policy.
The relationship in the second trimester
The second trimester is often the best time for your relationship during pregnancy. She feels better, the nausea has gone, her energy is back, and the anxiety of the first trimester has usually reduced. This is the window to invest in each other before the chaos of the third trimester and the newborn phase.
Go on dates
This sounds obvious, but it is easy to let the pregnancy consume every conversation and decision. Go for dinner. See a film. Walk somewhere that is not the route to a hospital. Talk about things that are not baby-related. You are still a couple. The baby will test that. Strengthen it now while you have the bandwidth.
Physical intimacy
Sex during the second trimester is safe for the vast majority of pregnancies. Many women find their libido returns or even increases as nausea fades and blood flow increases. Some do not, and that is also normal. Be led by her. Some positions become uncomfortable as the bump grows. Communicate, adapt, and do not take it personally if some days she would rather be cuddled than anything else.
If she has been told to avoid sex for a medical reason (low-lying placenta, bleeding, cervical issues), follow that advice without question.
Talk about your feelings
Somewhere around the middle of the pregnancy, many dads experience a quiet shift. The abstract idea of a baby starts becoming concrete. You may feel a mix of excitement, anxiety, impostor syndrome ("am I ready for this?"), and occasionally a flash of grief for the life you are leaving behind. None of this makes you a bad person. All of it is normal. Saying it out loud, to her, to a friend, to anyone, helps. Our new dad anxiety guide covers this in more depth.
Money and the second trimester
The financial reality of having a baby usually hits hardest in the second trimester, when you start pricing up car seats, prams, and nursery furniture, and simultaneously calculating what life looks like on reduced income during maternity leave.
Some perspective: you need far less than the baby industry wants you to buy. Our what you actually need for a newborn guide separates the essentials from the marketing. The biggest costs are: a safe car seat (new, not second-hand), a cot or crib with a new mattress, a pram, and nappies. Everything else is negotiable, borrowable, or can wait.
Financial prep worth doing now:
- Calculate your household income during maternity leave (statutory maternity pay is 90 percent of salary for 6 weeks, then roughly £184 per week for 33 weeks).
- Check whether your employer offers enhanced maternity or paternity pay beyond the statutory minimum.
- Build a buffer if possible: even a few hundred pounds set aside specifically for the first month makes a difference.
- Register for a Bounty pack (free samples), look at baby banks for second-hand clothes, and accept every hand-me-down offered. Babies wear clothes for about three weeks before outgrowing them.
When to call the midwife in the second trimester. Call the maternity unit if she experiences: heavy vaginal bleeding, severe abdominal pain, fluid leaking from the vagina, a significant reduction in baby movements after 24 weeks, sudden severe headache with visual disturbances, or significant swelling of face and hands. Do not wait for the next appointment.
Telling people and managing expectations
Most couples announce the pregnancy after the 12-week scan. The second trimester is when the wider world finds out and starts having opinions. A few things to brace for:
- Unsolicited advice: Everyone who has ever had a baby will tell you what to do. Develop a polite nod and a short response: "Thanks, we will look into that." Then ignore most of it.
- Belly touching: People will try to touch her bump without asking. She gets to decide whether this is fine or not. Your job is to back her up.
- Name opinions: If you share potential names, people will critique them. Consider keeping the shortlist private until the baby is born and named, at which point criticism is socially unacceptable.
- Work conversations: She will need to tell her employer by 25 weeks at the latest (to trigger maternity pay). You should tell yours when you are ready, and start the formal paternity leave conversation by the start of the third trimester.
The trimester-by-trimester dad guide
One printable PDF covering all three trimesters: what is happening, what to do, and the checklist for each stage. Free.
The bottom line for dads
The second trimester is the best trimester. She feels better. You have time. Use it. Go to the 20-week scan. Start the nursery. Book antenatal classes. Have the big conversations about money, childcare, feeding, and sleep. Go on dates. Feel the baby kick. And resist the temptation to drift back into your pre-pregnancy routine just because the urgency has faded.
This is the preparation window. The third trimester arrives fast and brings discomfort, appointments, and the creeping realisation that this baby is actually coming. Everything you sort in the second trimester is one less thing to panic about later.
FAQ
What happens at the 20-week anatomy scan?
The 20-week anomaly scan is a detailed ultrasound that checks the baby's organs, brain, spine, heart, kidneys, and limbs. It measures growth and checks the placenta position. It takes 20 to 30 minutes and is usually the most thorough scan of the pregnancy. You can find out the sex if you want, but you need to tell the sonographer before they start. If something is flagged, they will refer you for further investigation. Most scans are completely normal.
When can I feel the baby kick from outside?
She will probably feel flutters from around 16 to 20 weeks. You can usually feel kicks from the outside from about 24 to 28 weeks. Earlier is possible with a second baby. The trick is timing: the baby is most active after she eats, when she lies down, or in the evening. Place your hand flat and be patient. The first time you feel it is genuinely one of the best moments.
Should we find out the sex of the baby?
Entirely personal. About 60 percent of UK parents choose to find out. Advantages: you can plan names, clothes, and nursery with more specificity. You may bond differently when you can picture a son or daughter rather than an abstract baby. Disadvantages: the surprise at birth is a unique moment you cannot recreate. Some parents find that not knowing keeps the excitement higher. Whichever you choose, agree on it together.
When should we start setting up the nursery?
The second trimester is the ideal time to start planning. She has more energy than she will in the third trimester, and you are past the highest-risk period. You do not need to finish it now. Start with the big decisions: where the baby will sleep, what cot to buy, whether you need to clear a room. Aim to have the basics done by 34 to 36 weeks. A Moses basket or bedside crib is all you need for the first few months.
Is it normal for my partner's mood to improve in the second trimester?
Yes. The first trimester hormonal surge (which causes nausea, exhaustion, and mood swings) levels off around weeks 12 to 14. Many women feel significantly better: more energy, less nausea, improved mood. This is why it is called the golden trimester. But not everyone gets the golden experience. Some women continue to feel unwell, and that is also normal. Do not assume she should feel great just because the textbooks say so.
What antenatal classes should we book in the second trimester?
Book them now, attend them in the third trimester. NHS antenatal classes are free but fill up fast, so register early. NCT courses cost money but come with a ready-made parent group which can be invaluable, especially for dads. Look for classes that cover labour and birth, breastfeeding basics, and newborn care. Hypnobirthing courses are also worth considering. Most classes run in weeks 30 to 36.