Prenatal Yoga Poses by Trimester: A Guide for Yoga Teachers

Why the trimester matters in prenatal yoga

Pregnancy is one of the fastest and most extensive periods of physiological change in adult life. In around forty weeks, a woman’s body reorganises its circulation, breathing, hormonal balance and posture. The division into trimesters is a useful clinical convention rather than a rigid boundary, but it helps a teacher anticipate what each stage asks of the practice.

Plasma volume rises from the first trimester and reaches around 40 to 50% above its starting value at term, while heart rate climbs by 10 to 20 beats per minute (Sanghavi & Rutherford, 2014; Soma-Pillay et al., 2016). As the uterus grows, the centre of gravity moves forward and the lumbar curve tends to deepen.

Relaxin is often described as the hormone that loosens the joints. Its concentration actually peaks at around 12 weeks, while joint laxity increases progressively until birth, and a link with injury has not been established (Marnach et al., 2003; Dehghan et al., 2014). The practical conclusion still holds for the whole pregnancy: stability before range. For a wider overview, see our prenatal and postnatal yoga guide.

Circulation. Dilated vessels and blood pressure that tends to fall until mid-pregnancy make dizziness more likely, especially when changing level.

Breathing. Progesterone makes breathing fuller from early on; late in pregnancy the uterus raises the diaphragm by about four centimetres.

Emotions. Joy, apprehension and a changing body image accompany each stage and shape how a student arrives in class.

Medical clearance and when not to practise

Current guidelines encourage regular physical activity in pregnancies without contraindications (ACOG, 2020; Mottola et al., 2018), and prenatal exercise is not associated with miscarriage or stillbirth (Davenport et al., 2019a). That reassurance only holds within a clear framework. Every student completes a health questionnaire before her first class, such as the Get Active Questionnaire for Pregnancy (CSEP, 2021), and it is reviewed each trimester.

The teacher does not diagnose, interpret test results or contradict the healthcare team (Yoga Alliance, 2020). Their role is to screen, adapt, recognise warning signs and refer. Some precautions apply to every pregnant student: no heated rooms, no breath retention, no pressure on the abdomen, no forcing to the end of a movement, and only brief time flat on the back from around 20 weeks.

Absolute contraindications. Situations such as rupture of membranes, preterm labour or pre-eclampsia, in which practice does not begin or is suspended.

Relative contraindications. Conditions such as recurrent miscarriage or severe pelvic pain, in which a gentle practice may help, but only with clearance.

Signs to stop. Vaginal bleeding, fluid loss, painful regular contractions, chest pain, calf pain or swelling and, in the third trimester, reduced fetal movements.

How the practice changes across the three trimesters

First trimester (weeks 1 to 12). Fatigue and nausea dominate, and vasodilation makes dizziness more likely. Sessions become shorter and calmer, with slow transitions, no fasting and no heat. Telling students that practising less and resting more is also practice is part of the teaching. Women who have never done yoga can begin after screening.

Second trimester (weeks 13 to 27). Energy usually returns and the bump becomes visible, with the uterus reaching the navel at around 20 weeks. This is generally the best period for asanas, a time to build strength and stability with props supporting alignment.

Third trimester (weeks 28 to 40). Breathlessness on exertion, oedema, reflux and altered balance make comfort the priority. The pace slows, rest lengthens and preparation for birth takes a larger place.

Across all three stages, the Prenatal and Postnatal Yoga Teacher Training works from six principles, including function over form: a posture does not need to look like a photograph, it needs to fulfil its purpose. A few of the postures studied:

Tadasana. Helps the student find her new balance as the centre of gravity shifts.

Marjaryasana and Bitilasana. Cat and cow mobilise the spine and ease the lower back; they do not turn the baby (Hunter et al., 2007).

Virabhadrasana II. Builds leg strength and stability.

Balasana. Offers rest and relief for the lower back.

Breathing and relaxation in pregnancy

Breathing in pregnancy does not become faster and shallower: it becomes fuller. The volume of each breath rises by 30 to 50% while the rate stays practically the same (LoMauro & Aliverti, 2015). Because ventilation is already increased, fast or forced techniques such as Kapalabhati and Bhastrika easily cause dizziness, and breath retentions are avoided throughout pregnancy.

It is often claimed that breathing well oxygenates the baby. In a healthy pregnant woman, maternal blood is already almost fully saturated at rest, and fetal oxygenation depends on placental circulation (Soma-Pillay et al., 2016). The value of pranayama lies in respiratory comfort, a calmer nervous system and resources for labour. Mindfulness interventions in pregnancy are associated with lower anxiety, stress and depressive symptoms (Dhillon et al., 2017). From the middle of pregnancy, relaxation happens on the side or semi-reclined.

Complete breathing. Restores fullness and comfort to the breath.

Nadi Shodhana. A slow, rhythmic breath for balance and calm.

Gentle Ujjayi. An audible breath that anchors attention, useful between contractions.

Yoga Nidra. Systematic deep relaxation (Satyananda Saraswati, 1976) that needs no effort; imaging findings are still preliminary (Kjaer et al., 2002).

What you learn in the course

This article explains what changes and why. The method for adapting each posture, leading a mixed group and building a safe class is what the course teaches. Its trainer is Nélia Rodrigues, BeYoga’s trainer for pregnancy and postnatal yoga (about BeYoga School).

The course runs to 50 hours across 8 units, from pregnancy to the postpartum period. The 39 postures are demonstrated one by one on video with the options for each trimester, alongside complete practices, an interactive manual and a workbook. Access lasts 8 months, and the course counts as 50 hours of Yoga Alliance continuing education.

The English edition, with Nélia’s own voice translated with AI and reviewed by the BeYoga team, opens in January 2027. Join the waiting list on the course page or browse all our online courses in English.

Posture sheets. Each posture with its purpose, changes by trimester, precautions, contraindications and postnatal variation.

Practical applications. The adapted Sun Salutation, mudras and practice for common discomforts, with the signs that call for referral.

Birth and postpartum. Breath, voice and positions for labour, then the return to practice, diastasis recti and the pelvic floor.

Class planning. Sequencing, the five-part class structure, mixed-trimester groups, consented adjustments and ethics.

Final project. A written class plan and the video of a 60-minute class, assessed by Nélia.