Things to Consider During the First 3 Months of Pregnancy

The first 13 weeks of pregnancy are the period in which the baby’s organs form and the expectant mother’s body changes rapidly. This article summarises what to pay attention to in the first trimester and which symptoms require medical attention.

Fetal development in the first trimester

In the first weeks after fertilisation the foundations of the heart, brain, spine and other organs are laid. The heartbeat can be seen on ultrasound at week 6; by the end of week 12 the baby is about 5–6 cm long and most organs have formed. The first months are therefore the period most sensitive to external factors such as medication, alcohol, smoking and infections.

Common symptoms

• Nausea and vomiting: seen in about 70% of pregnant women; small frequent meals and dry food before getting out of bed may help. Vomiting that prevents fluid intake should be reported to the physician.
• Fatigue and sleepiness: related to rising progesterone; more rest is advised.
• Frequent urination, breast tenderness, mild pelvic ache: usually expected changes related to the growing uterus.
• Mood swings: related to hormonal change; persistent sadness or anxiety should prompt a request for support.

First visit and tests

The first assessment is ideally made at weeks 6–8. At this visit the pregnancy is confirmed to be inside the uterus with a heartbeat, and the gestational age is established. Blood group, full blood count, blood glucose, thyroid function, urine analysis and screening for infections such as hepatitis B, HIV, syphilis, rubella and toxoplasmosis are performed. Between weeks 11 and 14 the nuchal translucency scan with first-trimester screening, or optionally a cell-free fetal DNA test from maternal blood, is planned.

Nutrition and supplements

• Folic acid (400 mcg daily) should be taken throughout the first 12 weeks; the physician may increase the dose where indicated.
• 1.5–2 litres of water per day is recommended.
• Raw or undercooked meat, unpasteurised dairy products, raw eggs and high-mercury fish (swordfish, shark) should be avoided.
• Daily caffeine should be kept below 200 mg (about 1–2 cups of coffee).
• Iron and vitamin D supplements are recommended by the physician according to test results.

Things to avoid

Smoking, alcohol and recreational drugs must be stopped completely throughout pregnancy. Over-the-counter medicines, herbal products and supplements should not be used without consulting the physician. Pregnancy must be declared before any X-ray examination. Saunas, very hot baths and contact with cat litter (risk of toxoplasmosis) should be avoided.

Exercise and daily life

Where the physician agrees, light to moderate exercise such as walking, swimming and pregnancy yoga is recommended. Heavy lifting, sports with a risk of falling and exhausting activity should be avoided. It is useful to discuss working conditions with the physician.

Warning signs that need prompt care

• Vaginal bleeding
• Severe or one-sided pelvic pain, shoulder-tip pain (possible ectopic pregnancy)
• Persistent vomiting with inability to keep fluids down
• Fever of 38 °C or higher
• Burning and pain on urination