Weeks 13 and 17 of pregnancy

From weeks 13 and 14, the baby starts to move and may hiccup, but the movements are often too small to be felt. Some women start becoming aware of their baby moving as early as week 15, 16 or 17, but most find it takes a little longer than this.

Pregnant woman in her third trimester

What’s happening to the mother?

Weeks 13 and 14

At weeks 13 and 14, the uterus is the size of a grapefruit. It is common for you to gain weight during this period. Weight gain is usually one to four kilograms. Gestational nausea has usually subsided.

Weeks 15, 16 and 17

During this period, the stomach becomes larger and most people will find that the stomach becomes visible to others. During this phase, some women start to become aware of their baby moving, but most find that this takes a little longer.

Due to the amount of hormones in the body, you may experience mood swings.

It is common for your nose to become more blocked than usual, due to swollen mucous membranes. You may also find that you are sweating more than usual due to the increased amount of blood in your body. You will also get out of breath more easily than before because your heart has to supply enough oxygen for two people.

Development of the fetus

Weeks 13 and 14

The baby’s organs continue to grow. Urine production gets underway, and nails are fully grown on fingers and toes. Thin hairs grow on the body of the baby which protect its skin. The baby starts to move and may hiccup, but the movements are often too small to be felt.

All nutrients are passed to the baby via the placenta. The length of the baby from head to buttocks is between 60 and 74 millimetres.

Weeks 15, 16 and 17

During two weeks in this period, the weight of the fetus doubles from about 80 to 160 grams. The suction reflex is developed and the fetus begins to suck on its fingers.

Feel life

Tips for pregnant women on how to monitor your baby’s movements. Information in Arabic, English, Norwegian, Polish, Somali, Spanish, Tigrinya and Urdu.


Information about pregnancy, childbirth and the postnatal period in Arabic, English, Farsi, French, Norwegian, Polish, Somali, Tigrinya and Turkish aimed at immigrants and others with a short period of residence.

Content provided by The Norwegian Directorate of Health

The Norwegian Directorate of Health. Weeks 13 and 17 of pregnancy. [Internet]. Oslo: The Norwegian Directorate of Health; updated Monday, March 7, 2022 [retrieved Monday, May 27, 2024]. Available from: https://www.helsenorge.no/en/pregnancy-and-maternity-care-in-norway/pregnancy-week-by-week/pregnancy-weeks-13-and-17/

Last updated Monday, March 7, 2022