13 Weeks Pregnant: Symptoms And Baby Development

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How Many Months Pregnant Are You At 13 weeks?

At 13 weeks, you are three months pregnant and in the last week of the first trimester.

How Big Is Your Baby At 13 Weeks?

In the 13th week, the baby is about the size of a peach (1).. Babies usually measure around 2.91in (7.4cm) in length, and weigh around 0.81oz (23g)

Baby Development At 13 Weeks

Here is how the baby develops in this week of pregnancy:

Body organsDevelopments
Face (2)Lips and nose fully formed. Fetus makes facial expressions
Eyelids (3)Formed and closed to protect eyes, which are still developing
ArmsGrowing; are long and thin
HandsCan make a fist
Hair follicles (4)Developing
IntestineGrowing into the abdomen, as an internal organ
Tooth budsDeveloping
Genitals (5)In boys, testes are formed inside the body and genitals are developing outside. In girls, ovaries are fully formed, and the clitoris is forming outside the body
Liver (6)Secretes bile
Pancreas (7)Starts producing insulin
Kidneys (8)Starts producing urine, which is passed into the amniotic fluid

As the baby changes, you will also experience specific symptoms of pregnancy in this week.

What Symptoms Do You Experience In The 13th Week Of Pregnancy?

By this week, the morning sickness subsides(8), and you start feeling energetic. However, if you are carrying twins or multiple babies, then the morning sickness may persist. Here are some other symptoms you will experience during the 13th week of pregnancy:

  • Increased energy level, as the morning sickness comes to an end by the beginning of the second trimester.
  • Food cravings/aversions due to hormonal fluctuations. You may even crave for certain foods and dislike others.
  • Indigestion/constipation as the progesterone hormone relaxes the digestive tract, slackens the digestion process, and can also cause gas and bloating.
  • Dizziness, due to reduced blood pressure, as more blood is pumped to the fetus.
  • The hormonal changes increase the vaginal discharge or mucus that prevents bacteria from traveling to the uterus.
  • The urge to urinate more frequently increases due to hormonal changes.
  • Reduced sense of smell and aversion to certain smells due to a change in the hormonal levels.

Along with these, you will also notice physical and emotional changes.

Changes In The Body At 13 Weeks

Here are some physical and emotional changes that you might experience during this week:

Visible blue veins on breast and legs due to increased blood flow (9).

Increased sex drive. The mucus plug covering the cervix helps prevent any infection. This allows you to have a safe, intimate time during this week.

  • Pregnant belly might not be visible in first-time moms, but may be evident in second-time moms.
  • Tender and sore breasts
  • Bigger areola and nipples
  • Linea nigra
  • Mood swings
  • Anxiety

When To Call The Doctor

If you notice any of the following symptoms, then call the doctor right away (9):

  • Pelvic pain other than cramping
  • Severe vomiting
  • Feeling unconscious
  • Fever (100.4 degrees or higher)
  • Less frequent urination or dark colored urine

If everything is normal, a regular OB/GYN checkup should do.

Your OB/GYN Visit

These are the following things you can expect during your OB visit:

  • Blood pressure
  • Weight check
  • Combined screening test evaluates the risk of chromosomal abnormalities in the baby. It includes an ultrasound scan along with a blood test (10).
  • Ultrasound for nuchal translucency is done to evaluate the thickness of the fluid behind the baby’s neck. The thicker the fluid, the greater is the risk of Down syndrome in the baby.
  • Gestational age and nasal bone determination to visualize the nasal bone and determine the fetal gestational age. The nasal bone may not be properly visible in babies with Down syndrome.
  • A blood test measures the level of proteins in the blood sample.
  • PAPP-A, a placental protein produced during early pregnancy with an unsatisfactory result indicates the risk of chromosomal abnormalities.
  • An abnormality in the level of this placental protein human chorionic gonadotropin indicates the risk of chromosomal abnormality.

The risk of Trisomy 18 and Down syndrome can be assessed from the combined results of these tests. In the case of abnormal test results, the doctor recommends additional testing like ultrasounds, amniocentesis, cell-free fetal DNA, or chorionic villus sampling.

Tips For Mom-to-be

  • Drink plenty of water and stay hydrated.
  • Eat home cooked food and follow a healthy lifestyle.
  • Avoid raw, undercooked, and deep-fried foods.
  • Avoid fish such as king mackerel, shark, tilefish, or swordfish that are high in mercury.
  • Carry snacks and fruits to the office to munch on in regular breaks.
  • Do not take an excess of caffeine.
  • Do not forget to take prenatal vitamin supplements such as iron and folic acid.
  • Indulge in mild exercises like walking to feel the burst of energy level. Pregnancy yoga also helps tone your pelvic muscles.
  • Keep all stress and fears at bay.
  • Get enough rest.
  • Use moisturizers to prevent dry and itchy skin.
  • Avoid taking any over-the-counter medicines without the doctor’s permission.
  • Wear breathable and loose clothes, nursing bras to support the breasts, and comfortable footwear.
  • Spend quality time with your near and dear ones.

Talk to your partner about how he can help you.

Tips For Dad-to-be

Your partner can offer support to you by:

  • Sharing the household responsibilities.
  • Accompanying you during the workouts.
  • Going to the hospital visits with you.
  • Creating a pleasant environment at home.
  • Making you feel refreshed by planning a day out.
  • Planning maternal shopping.
  • Giving you a good neck and foot massage.
  • Spending quality time with you.

You may notice decreased morning sickness symptoms and increased energy by the end of the first trimester or when you are 13 weeks pregnant. However, food cravings, indigestion, vaginal discharge, and urinary frequency may increase. You should seek immediate medical help if you develop fever, pelvic pain, or urinary changes. The prenatal checkup includes tests to predict chromosomal abnormalities, nuchal translucency, etc. Ensure you take a balanced diet, stay hydrated, and exercise moderately. Would-be-dads may also pitch their much-needed help to comfort mamas.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
  1. 13 weeks pregnant, NHS.
  2. Fetal development, Embryology.
  3. Prenatal Summary, The Endowment for HUman Development.
  4. Hatem A Tawfik et al.; (2016); Embryologic and fetal development of the human eyelid.
  5. Pregnancy week by week, Due date calculator.
  6. Boy or girl? The difficulties of early gender prediction, UT Southwestern Medical Center.
  7. Antonella Giancotti et al.; (2019); Functions and the emerging role of the foetal liver into regennerative medicine.
  8. 13 weeks pregnant, APA.
  9. Varicose veins during pregnancy, PennMedicine.
  10. Warning signs during pregnancy, Pregnancy Birth and baby.
  11. Common tests during pregnancy, John Hopkins Medicine.

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shreeja pillai

Shreeja holds a postgraduate degree in Chemistry and diploma in Drug Regulatory Affairs from the University of Mumbai. Before joining MomJunction, she worked as a research analyst with a leading multinational pharmaceutical company. Her interest in the field of medical research has developed her passion for writing research-based articles. As a writer, she aims at providing informative articles on health... more

Dr. Richa Hatila Singh

Dr. Richa Hatila is an experienced gynecologist practising in Varanasi. She did her MS in Obstetrics and Gynaecology, DNB, and a Fellowship in Laparoscopic surgeries (FMAS). She is currently associated with Shubham Hospital and Sah Speciality Clinic in Varanasi.