Pregnancy Week 16: Baby Size & Practice

At 16 weeks

At 16 weeks pregnant, your baby is about the size of a guava (amrood), around 11.6 cm from head to bottom (NHS) and about 144 g at the WHO median. A growth spurt is coming: your baby will roughly double in size over the next month, and every joint is now working. You may feel the first movements, especially if this is not your first pregnancy.

Your Baby at 16 Weeks

Your baby is about to have a growth spurt and will roughly double in size over the next month. The eyes are no longer at the sides of the head, the ears are in place, every joint is working, and the umbilical cord is fully formed with 2 arteries and 1 vein (Pregnancy, Birth and Baby).

Your baby is starting to pull faces, though the NHS says any smiling or frowning is random because there is no muscle control yet. The developing nervous system lets your baby move arms and legs, form fists and perhaps punch around inside you. The WHO Fetal Growth Charts put the median estimated weight at about 144 g; healthy babies vary widely, and your scan report is what matters.

Your Body This Week

At a check-up around now, your midwife or doctor may weigh you, check your blood pressure and test a urine sample for protein, which can signal a risk of pre-eclampsia, and you might hear the heartbeat for the first time (NHS). Constipation is common; fibre from wholemeal bread, fruit, vegetables, beans and lentils, with plenty of water and regular exercise, can help.

Extra blood volume and hormones can bring varicose veins and leg cramps, and relaxed ligaments can strain the joints of your lower back and pelvis. Pregnancy, Birth and Baby suggests standing straight, bending and lifting correctly, and doing simple stretches to ease backache.

When to call your midwife or doctor: If you feel unwell and it is getting you down, speak to your doctor or midwife, and seek medical advice for any bleeding (NHS). Not feeling movements yet is normal, but contact them if you have felt none by 24 weeks (Pregnancy, Birth and Baby).

Garbh Sanskar This Week

A small daily practice for this stage, from Mamta’s 1:1 sessions. It is tradition and gentle self-care, not medical advice, so keep every check-up and follow your doctor or midwife first.

Mantra: The Garbharakshambika Stotram is a devotional hymn linked to the Thirukarukavur temple near Thanjavur, asking the goddess Garbharakshambika to protect the devotee and the beings in the womb. Read or chant one verse softly each evening, with no required number of repetitions; the Garbh Sanskar mantras guide explains how it differs from the Garbha Raksha Stotram.
Music: Let a favourite bhajan or soft instrumental piece play while you write down questions for your check-up. The listening is for your own calm, and there is no right or wrong choice of music.
Gentle movement: Mamta suggests a few minutes of gentle stretching for the back and legs, such as slow shoulder rolls and seated calf stretches, breathing evenly without holding your breath. Begin only with your doctor's or midwife's clearance.
Food: Traditionally, Charaka's fourth month continues with milk and a little butter, and you can pair it with fibre-rich dal, vegetables and wholemeal roti to help with constipation. Enjoy these alongside the iron, calcium and folic acid your doctor recommends.
Garbh samvad (a line to say to your baby): You are growing so fast, little one, and I'm happily making room for you.

Check-ups Around This Week, Wherever You Live

Around 16 weeks, care in each country turns to the mid-pregnancy visit and planning the detailed scan.

Where you live	What is usually offered
India	Government guidelines advise at least four antenatal visits, with the second between 14 and 26 weeks, and calcium (1 g a day) from 14 weeks, taken at a different time from your iron and folic acid tablet. Your doctor will usually advise an anomaly scan around 18 to 20 weeks.
UK	The NHS offers an antenatal appointment at 16 weeks, and the whooping cough vaccine can be given from 16 weeks, usually around 20. The 20-week screening scan follows between 18 and 21 weeks.
USA	Visits are traditionally every 4 weeks until 28 weeks, although ACOG now supports schedules tailored to each woman, including telehealth. The anatomy ultrasound is usually done between 18 and 22 weeks.
Australia	The morphology scan is done between 18 and 22 weeks, and the whooping cough (pertussis) vaccine is recommended in every pregnancy, ideally between 20 and 32 weeks.

Schedules change and differ between hospitals, so your own care team’s plan always comes first.

Questions About Week 16

What happens at a check-up around 16 weeks?

The NHS says your midwife will usually weigh you, check your blood pressure and test your urine for protein, and you might hear your baby's heartbeat for the first time. You will also get the results of the blood tests from your booking appointment, which usually include tests for HIV, hepatitis B and syphilis.

How can I ease constipation at 16 weeks pregnant?

The NHS suggests high-fibre foods such as wholemeal bread, fruit, vegetables, beans and lentils, regular exercise and plenty of water. Iron supplements can make it worse, but talk to your doctor or midwife before stopping any medication.

Can I feel my baby move at 16 weeks?

Some women do, especially if they have been pregnant before, but many won't notice movements for a few more weeks. Pregnancy, Birth and Baby advises contacting your doctor or midwife if you haven't felt your baby move by 24 weeks.

Practise With Mamta, Wherever You Are

Mamta guides expecting mothers through private 1:1 Garbh Sanskar sessions online, scheduled in your own time zone, from the first trimester to the last week. Start with a free conversation on WhatsApp or read how sessions work.

Sources

Mamta is not a doctor. Medical points on this page come from the sources below, checked in October 2026. Sizes are approximate and babies vary; your scan report is what matters.