The second trimester: what to expect from weeks 13 to 27

Pregnancy · Updated July 2026 · All articles

For many people, the second trimester brings a welcome shift. The relentless nausea and exhaustion that can make the first trimester so hard begin to ease, energy starts to come back, and pregnancy starts to feel a little more manageable. The bump becomes visible, you will likely feel your baby move for the first time, and the all-important anomaly scan gives you a detailed picture of how your baby is developing. This guide covers what happens week by week and what to expect from this middle stretch of pregnancy.

When the second trimester starts and ends

The second trimester begins at the start of week 13 and runs to the end of week 27. In terms of calendar weeks, that is roughly four months. It sits between the first trimester (weeks one to twelve) and the third trimester (week 28 to birth). Most people find this the most comfortable of the three, which is why it is sometimes called the honeymoon trimester, though that label is not quite right for everyone. Some people continue to experience nausea or new discomforts in the second trimester, and emotional responses to pregnancy are not determined by which trimester you are in.

Why the second trimester often brings relief

The extreme fatigue and nausea of early pregnancy are largely driven by the rapid rise in human chorionic gonadotropin (hCG) in the first trimester. By weeks 12 to 14, hCG levels plateau and then begin to fall as the placenta takes over progesterone production. For most people this hormonal shift brings genuine relief: nausea settles, appetite returns, and sleep becomes easier. Energy levels often improve noticeably around weeks 13 to 16, though this varies considerably. If you are still feeling unwell into the second trimester, speak to your midwife. Hyperemesis gravidarum (severe pregnancy vomiting) can persist beyond 12 weeks and needs medical support, not just reassurance that it will pass.

The risk of miscarriage also falls significantly once you reach the second trimester, which for many people brings emotional relief alongside the physical improvement. The anxiety of the first trimester does not vanish instantly, but passing the 12-week mark is a real milestone and one worth acknowledging.

Physical changes: your bump and weight gain

The uterus begins to rise out of the pelvis around week 12, and by the middle of the second trimester most people are clearly showing. In a first pregnancy, a visible bump often appears between weeks 16 and 20. In a second or subsequent pregnancy it tends to be earlier, sometimes as early as weeks 14 to 16, because the abdominal muscles have already been stretched. By the end of the second trimester at week 27, the fundus (the top of the uterus) reaches roughly to the navel or just above.

Weight gain accelerates during the second trimester. While weight gain in the first trimester is typically small (often less than two kilograms), the second trimester sees the baby growing rapidly and fluid volumes increasing. There is no single "right" amount of weight to gain, and guidance varies based on your pre-pregnancy weight and individual circumstances. Your midwife will monitor this as part of routine antenatal care. What matters most is that you are eating enough to support the pregnancy, not that you are hitting a specific number on the scale.

Other physical changes in the second trimester include the appearance of a linea nigra (a dark vertical line on the abdomen), skin changes such as stretch marks beginning to form as the bump grows, breast changes as they continue preparing for feeding, and in some cases Braxton Hicks contractions from as early as 16 to 20 weeks.

The anomaly scan at 18 to 20 weeks

The mid-pregnancy anomaly scan, sometimes called the 20-week scan, is offered between 18 weeks and 20 weeks and 6 days on the NHS. It is a detailed ultrasound examination that checks the baby's physical development in much more depth than the 12-week dating scan. The sonographer examines the brain and skull, face, spine, heart, stomach, kidneys, bladder, limbs and abdominal wall. The position of the placenta is also noted, as a low-lying placenta (placenta praevia) affects birth planning.

The anomaly scan cannot detect every condition, and it is important to understand what it can and cannot do before you go. It can identify structural differences in organs and limbs, but it will not pick up conditions such as Down's syndrome (which is screened for separately in the first trimester) or conditions that are not visible on ultrasound. If a concern is found at the anomaly scan, you will usually be referred to a fetal medicine specialist for further assessment. The vast majority of anomaly scans are reassuring and give a clear picture of a well-developing baby.

If you want to know the sex of your baby, the sonographer may be able to tell you at this scan, depending on the baby's position. Let the sonographer know at the start whether you would like this information or prefer not to know.

Feeling your baby move for the first time

One of the most significant moments in the second trimester is feeling your baby move for the first time, a sensation known as quickening. In a first pregnancy this typically happens between 18 and 22 weeks. In a second or subsequent pregnancy many people notice it earlier, from around 16 weeks, because they recognise what the sensation feels like. Early movements are often described as flutters, bubbles, or a gentle knocking. They can easily be mistaken for gas at first.

As the weeks progress, movements become more frequent and more distinct. By around 24 to 28 weeks most people are feeling regular, recognisable kicks and rolls. From 28 weeks, monitoring your baby's movements becomes an active part of antenatal care (see the third trimester overview for guidance). In the second trimester the main thing to note is that you should be feeling your baby move by around 24 weeks, and if you have not noticed any movements by that point, speak to your midwife rather than waiting.

Changes you might not expect

The second trimester brings several changes that are less commonly discussed but very real.

Dental changes: increased progesterone and oestrogen during pregnancy make the gums more sensitive and prone to inflammation, a condition called pregnancy gingivitis. Bleeding gums during brushing are common. This is also why NHS dental care is free throughout pregnancy and for 12 months after birth. A dental check in the second trimester is worthwhile and well within the safe window for any non-urgent treatment.

Vision changes: hormonal changes and increased fluid retention can alter the shape of the cornea slightly, causing some people to find their glasses or contact lenses less comfortable. This typically resolves after birth, but it is worth mentioning to your optometrist if it is bothering you. Sudden visual disturbances such as blurring, flashing lights or spots should always be reported to your midwife promptly as they can be signs of pre-eclampsia.

Changes in sex drive: libido is genuinely unpredictable in pregnancy. Some people experience a noticeable increase in sex drive in the second trimester as nausea fades and energy returns. Others find that physical discomfort, anxiety or simply a changed relationship with their body means interest is low. Both are completely normal. Sex is safe in most pregnancies throughout the second trimester; your midwife will advise you if there is a specific reason to avoid it.

Emotional changes and mental health

The second trimester is often described as a time of settling emotionally, as the anxiety of the first trimester gives way to something that feels more stable. But this is not true for everyone. Some people find the growing visibility of the pregnancy brings its own anxieties, particularly around body image, the reality of impending parenthood, or past pregnancy losses.

Antenatal depression and anxiety affect a significant number of people during pregnancy and are not spoken about as openly as they should be. If you are feeling consistently low, worried, or disconnected from your pregnancy, tell your midwife at your next appointment. This is a routine part of antenatal care and your midwife will not judge you. Support is available and effective.

The second trimester is also often when people begin to tell their wider circle of family, friends and colleagues about the pregnancy. This is a personal decision and there is no obligation to disclose at any particular point. If you are navigating a complicated situation, such as telling an employer about pregnancy-related illness, your rights at work begin from the moment you are pregnant.

Preparing for the third trimester

The second trimester is a good time to start preparing for what comes next, without the urgency of the third trimester bearing down on you. Consider attending antenatal classes, which often start in the late second or early third trimester. If you are planning to breastfeed, a breastfeeding information session now means you have absorbed the basics before a sleep-deprived baby arrives.

It is also a good time to start thinking about your birth preferences, even if you are not ready to write them down yet. Reading about the different stages of labour, pain relief options and what happens in both a vaginal birth and a caesarean section helps you feel more informed going into the third trimester. You do not need to make firm decisions in the second trimester, but knowing the landscape of choices helps later conversations with your midwife feel less overwhelming.

Frequently asked questions

When does the second trimester start and end?

The second trimester runs from week 13 to the end of week 27. It follows the first trimester and is replaced by the third trimester at week 28.

When will I start showing in the second trimester?

Most people notice a visible bump between weeks 16 and 20 in a first pregnancy, though it can be earlier in subsequent pregnancies. By the end of the second trimester at week 27, the bump is clearly visible to everyone.

When is the anomaly scan and what does it check?

The anomaly scan is offered between 18 and 20 weeks and 6 days. It checks the baby's brain, heart, spine, kidneys, limbs and other structures. It can also detect the position of the placenta and may show the baby's sex if you want to know.

When should I feel baby move in the second trimester?

First-time parents usually feel the first movements between 18 and 22 weeks. In a second or subsequent pregnancy you may notice them as early as 16 weeks. Early movements are often described as flutters, bubbles or a gentle tapping sensation.

Can I have sex in the second trimester?

Sex is safe for most pregnancies in the second trimester. Some people notice increased libido as nausea fades and energy returns. Always follow your midwife's guidance if you have placenta praevia, unexplained bleeding or other complications that may mean sex is not advised.

What should I eat in the second trimester?

The same balanced diet principles from the first trimester continue. Iron and calcium demands increase as the baby grows, so include plenty of iron-rich foods (lean meat, legumes, dark leafy vegetables) and calcium-rich foods (dairy, fortified alternatives, broccoli). Continue your folic acid or switch to a pregnancy multivitamin with vitamin D.

This article is for general information only. Always consult your midwife, obstetrician, or GP for advice specific to your pregnancy.