16 weeks pregnant: the whooping cough jab and antenatal classes

At 16 weeks pregnant your baby is about 12cm long and weighs about 146g, KKH says, roughly the size of an avocado. You've reached the four-month mark. Two things open up in Singapore this week: the window for the whooping cough vaccine, and registration for KKH's antenatal classes.

Your baby at 16 weeks

• The heart is pumping about 3.8 litres of blood a day.
• Hearing is working, though not fully developed, and your baby can start reacting to sounds and music from outside.
• Your baby makes sucking, swallowing and breathing movements, and can move the eyes, HealthXchange says.
• Your baby is moving, even if you can't feel it yet. KKH says first movements usually come between 16 and 22 weeks.

The whooping cough vaccine: 16 to 32 weeks

KKH strongly advises two vaccines in pregnancy, the flu jab and the whooping cough (pertussis) vaccine. For whooping cough, KKH says the best time is between 16 and 32 weeks. It gives your baby protection against whooping cough in the first few weeks after birth, and whooping cough can kill newborn babies.

SingHealth recommends one dose in every pregnancy, however recently you had the last one. If you miss the window, it can still be considered after 32 weeks, the Health Appointment System says, though it may protect your baby less. Ask at your next antenatal visit.

Antenatal classes: book from 16 weeks

KKH recommends registering for its antenatal programme after 16 weeks, so there's time to finish before the birth. It covers labour and delivery, breastfeeding, newborn care and a talk on nurturing your child. Fees on KKH's page when we checked:

Registration closes 2 weeks before each class starts, or earlier if it fills. KKH patients can also sign up for a free breastfeeding class. Our antenatal classes guide compares other providers.

Your week 16 checklist

When to call the hospital

Bleeding, fluid leaking, painful tightening, severe headache, fainting, chest pain or breathlessness need a same-day check.

At KKH, early pregnancy problems such as bleeding and tummy pain go to the Urgent O&G Centre, a 24-hour walk-in centre at Basement 1 of the Women's Tower. For minimal bleeding or mild pain under 16 weeks, KKH's Early Pregnancy Assessment Unit offers appointments the same or next working day. Booked elsewhere? Call that hospital's O&G clinic, or go to its emergency department after hours.

Frequently asked questions

How big is my baby at 16 weeks?

About 12cm and 146g, KKH says, about the size of an avocado.

Can I get the whooping cough vaccine while pregnant?

Yes. KKH recommends it in every pregnancy, ideally between 16 and 32 weeks, to protect your newborn.

Can I feel my baby move at 16 weeks?

Possibly. KKH says first movements usually come between 16 and 22 weeks, and HealthXchange says first-time mums often notice them at 18 to 20 weeks.

16 weeks pregnant is how many months?

Four months. KKH calls week 16 the 4-month mark.

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