Reaching 17 weeks pregnant means you are comfortably into your second trimester, a stretch of pregnancy that many parents-to-be find calmer and more energising than the early weeks. Your baby is growing quickly, your bump is becoming more noticeable, and the mid-pregnancy anomaly scan is now on the horizon. This week is a good moment to look after yourself and to plan the appointments that lie ahead.
Every pregnancy is different, so treat the milestones below as a general guide rather than a fixed timetable. If anything feels unusual for you, your midwife is always the best first point of contact.
Your baby at week 17
By week 17 your baby measures roughly 11 to 13 centimetres from head to bottom and weighs in the region of 140 to 150 grams, around the size of a pomegranate. These figures are approximate, and healthy babies vary a good deal at this stage.
A great deal is happening beneath the surface this week. The soft cartilage that formed your baby's early skeleton is gradually hardening into bone, and a layer of protective fat is beginning to develop. Your baby's ears are settling into their final position, and the tiny, unique pattern of fingerprints is starting to form on the fingertips.
Your baby is also becoming more active, practising movements such as flexing, stretching and even the occasional hiccup. Many parents do not feel these first flutters, often described as quickening, until somewhere between 16 and 24 weeks, so do not worry if you have not noticed anything definite yet, particularly if this is your first pregnancy.
Your body at week 17
As your uterus expands, you may notice a range of new sensations. Some of the more common second-trimester symptoms around this week include:
- Round ligament pain, a short, sharp or pulling feeling low in your abdomen as the ligaments supporting your growing uterus stretch.
- A growing bump and the beginnings of a more pronounced pregnancy shape.
- Backache or general aches as your posture and centre of gravity shift.
- An increased appetite now that early nausea has often eased.
- Skin changes, mild swelling, or a stuffy nose and occasional nosebleeds caused by pregnancy hormones and increased blood flow.
All of these are typically a normal part of pregnancy. That said, you should contact your midwife or maternity unit promptly if you experience severe or persistent abdominal pain, vaginal bleeding, a bad headache with visual disturbance, or any sudden swelling, as these need to be checked.
What to keep in mind this week
This is a settled, practical phase of pregnancy, which makes it an ideal time to tick a few things off your list. In line with NHS guidance, you might focus on:
- Continuing your pregnancy vitamins, particularly vitamin D, and eating a varied, balanced diet.
- Staying gently active, with walking, swimming or antenatal classes all generally suitable options.
- Looking after your comfort as your bump grows, with supportive footwear and mindful posture.
- Discussing the whooping cough vaccine with your midwife, which is routinely offered from around 16 weeks to protect your baby in the early weeks after birth.
Aches and tension in your back and hips are common as your body changes. A pregnancy massage with a practitioner experienced in caring for expectant mothers can be a soothing way to ease muscular tightness and take some time for yourself.
Scans, tests and appointments
The next major milestone in your NHS antenatal care is the 20-week screening scan, also known as the anomaly scan, which is routinely offered between 18 and 21 weeks. This detailed scan checks your baby's development and physical growth. As you are approaching that window, week 17 is a sensible time to make sure your appointment is booked.
Some parents choose to arrange a private private anomaly scan alongside or ahead of their NHS appointment, either for extra reassurance or for a longer, unhurried appointment. Booking ahead is worthwhile, as availability within the ideal gestational window can be limited.
Looking further ahead, other routine points in pregnancy include glucose tolerance testing for those who need it, usually offered around 24 to 28 weeks, and the RSV vaccination, offered from around 28 weeks. Your midwife will let you know which apply to you and when. To see how these milestones map onto your own dates, our pregnancy journey planner lays out a personalised week-by-week timeline.
Looking ahead
Week 17 is a reassuring, forward-looking stage: your baby is growing steadily, many early symptoms have settled, and the anomaly scan is within sight. If you have just arrived here, you may find it helpful to look back at week 16, and next you can read on to week 18 as you move closer to that important mid-pregnancy scan.
This article is for general information only and is not a substitute for professional medical advice. Always speak to your midwife, GP or obstetrician about your own pregnancy.
