12 weeks pregnant: the end of the first trimester

You've reached 12 weeks pregnant, the end of the first trimester. Your baby is about 5.1cm long, roughly the size of a lime, KKH says, and every organ has now formed. The risk of miscarriage drops from here: up to 80% of miscarriages happen in the first trimester.

First trimester screening is still open until 13 weeks 6 days. If you plan to tell work soon, MOM's rules are set out below.

Your baby at 12 weeks

• Organ formation is complete, though the organs are still maturing.
• The eyes, which started at the sides of the face, are moving towards the middle, and the ears are settling at the sides of the head.
• Bone is about to start hardening in the skull and the long bones.
• The intestines, which grew outside the belly, are rotating back in through the belly button. KKH says this finishes in about two weeks.
• Fingernails start to form this week, HealthXchange says.

HealthXchange puts your baby at just over 6cm and about 14g by the very end of the first trimester.

Your body at 12 weeks

Your womb is now about the size of a grapefruit, so your jeans may feel tighter, especially if you were slim before. First trimester symptoms are easing for many women.

Dizziness or fainting can carry on through the first 20 weeks. KKH explains that your blood pressure falls as your blood vessels relax, and standing for a long time or getting up quickly makes it worse. Take your time getting up.

Telling work: what MOM actually requires

When you share the news at work is your call; our guide on when to announce your pregnancy covers family, friends and work. MOM's rules are about the leave and your protection:

• Notice. For Government-Paid Maternity Leave (16 weeks, for a Singapore citizen child), you must tell your employer at least 4 weeks before the leave starts. For the 12 weeks under the Employment Act, it's at least 1 week. Without notice you get half the pay unless you have a good reason. The maternity leave calculator works out your dates.
• Protection. If you've served your employer for at least 3 months, MOM protects you against dismissal without sufficient cause and against retrenchment during pregnancy, as long as a doctor certified the pregnancy before the notice.
• Your partner. Fathers get 4 weeks of Government-Paid Paternity Leave, with 4 weeks' notice. Shared parental leave is 10 weeks for children born from 1 April 2026, split between you. See the paternity leave calculator and shared parental leave calculator.

Our guide to maternity and paternity leave in Singapore covers pay, flexible leave and who reimburses whom.

Checks still open this week

KKH recommends folic acid until 12 weeks, and its planner lists a multivitamin with iron among the pregnancy dos. Our prenatal vitamins guide compares options; check the doses with your doctor.

When to call the hospital

Bleeding, cramping pain, fluid leaking, fainting, chest pain or breathlessness all need a same-day check. If you've had more than one miscarriage, KKH suggests seeing a specialist to look for an underlying cause.

KKH's Urgent O&G Centre, at Basement 1 of the Women's Tower, takes walk-ins 24 hours a day for early pregnancy problems such as pain and bleeding. Under 16 weeks, if the bleeding is minimal or the pain is mild, its Early Pregnancy Assessment Unit can see you the same or next working day by appointment. If you're booked with another hospital, call its O&G clinic or go to its emergency department.

Frequently asked questions

Does the miscarriage risk drop after 12 weeks?

Yes. KKH says up to 80% of miscarriages happen in the first trimester, so the risk is lower from here.

Do I have to tell my employer at 12 weeks?

No. MOM's notice rule is at least 4 weeks before Government-Paid Maternity Leave starts, or 1 week for Employment Act leave.

12 weeks pregnant is how many months?

About three months, counted from the first day of your last period.

Can I stop folic acid at 12 weeks?

KKH recommends folic acid until 12 weeks. Ask your doctor whether to carry on with a pregnancy multivitamin; KKH's planner lists one with iron among its dos.

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