First Trimester – the starting line
In the first trimester, men can find it a challenge to feel safe and secure about the pregnancy.  Often they’re waiting for the first 12 to 14 weeks to pass when the risk of something going wrong, like a miscarriage, is at its highest. If you’ve had a previous miscarriage, then it can make those first weeks a time of uncertainty and worry for both you and your partner. 
Sometimes men can appear to be low-key about the pregnancy when in actual fact they are just waiting to get through that first trimester. And for this reason, there can often be misunderstandings between the expectant parents. Know that this can be an emotional time. Fluctuations in hormones and emotions may see your partner being much more emotionally expressive and seem less rational than usual.

Second Trimester – nesting
Considered to be the least turbulent trimester. For most women morning sickness has settled, whereas for others this can continue until after 20 weeks which can be disappointing for these mums as the associated physical symptoms can mean they are not able to enjoy the pregnancy as much as they expected or hoped to.
This is a time when your partner is usually more able to feel the baby moving, there is a sense of excitement about the pregnancy and her energy levels return. This is often a time when women have a psychological tendency to ‘nest’. For men this can be evidenced through trips to baby shops, preparing a nursery and assembling cots and baby accessories. 
The second trimester can also be a time for you to start reflecting on the kind of father you want to be. And it’s during this time of reflection that issues from your own childhood or family of origin can emerge.  You might be surprised to find troubling issues come to mind, perhaps that you have had with your own father. During this trimester think about the positive aspects of your childhood, as well as the negative, so that you can decide what’s going to be most important for you, as a dad, once your baby is born.
If you are experiencing additional stress, or perhaps thoughts of anxiety and depression now is a good time to take the step of getting help and being proactive about your feelings. You might need some additional help with a friend or a counsellor to help put strategies in place to assist you in recovering as quickly as possible so that you can start by being the best dad that you can be when the baby is born.

Third trimester – getting ready
The anticipated birth date is getting closer and starting to become a major focus. Try to attend birth classes and if you’re going to be present at the birth take advantage of learning as much as you can about how to be supportive for your partner when she is in labour and delivering. Women whose partners are supportive tend to have a better experience during labour meaning your presence and your support is very significant and can make a difference.
You might also want to attend some of the antenatal care appointments to help feel informed and able to contribute to planning for the baby’s arrival.  It is ideal for you both to discuss your ideas about birth and your partners preferences for pain management so that you are aligned prior to the event. 
Documenting these preferences as a birth plan, a record of what you think is going to be most helpful for you both during labour and the birth. This might also include any extra supports you or your partner may want due to antenatal anxiety or depression – such as being kept informed, access to additional support people or the use of medication. Give this to your midwife and/or obstetrician before labour starts so that the staff are informed.  Keep in mind, however, that the birth plan does not predict how labour and birth will go.  Dads need to bring an open and flexible approach to the birth so that they can adapt to what mum needs and to advocate for her as her labour may change and alter.
Anecdotally men seem to find birth a stressful but manageable event, often reflecting afterwards that it was not as bad as they had feared.  For some men it might be their first contact with a hospital or a medical procedure, and if things don’t go to plan (which can and does happen) they can sometimes feel out of control and/or afraid for their partner or baby. This can be a normal response. Where mum or dad do find the birth a traumatic experience they may have thoughts and associated responses that can persist for weeks and months. If that is your experience you should think about seeking professional help so you can work through the traumatic experience and your responses. Talking with your GP to get a referral for a counsellor is a great place to start.
For many dads, their sex life can change dramatically during the pregnancy, usually involving a reduction in their sexual activity. Most dads understand this and manage it with the patience and sensitivity that their partner needs.   Alternatively some men report an increase in their partner’s libido, which means they have the benefit of enjoying more lovemaking during their pregnancy.
At times pregnancy can bring up issues for a couple that they may not have been aware of previously and they need to work through which helps enable them to be the best team they could be once the baby is born. If you feel you are having more arguments than previously it may not necessarily be a sign that your relationship is on the rocks, but a sign that you are in the process of reorganizing your relationship in anticipation of parenthood.