Not only will this matter to you during your pregnancy, but it may also affect your child's health throughout the course of their life.
Of course, conceiving to a timetable is far more difficult than it sounds, and even the most carefully calculated pregnancies may arrive unexpectedly!
However, if you'd like more information to help you choose an approximate time of the year, read on.
When to have a baby: the weatherYou may decide that you want a baby to be born in early autumn, so they're old for their school year, but you should bear in mind that means you'll be pregnant during the summer. Carrying a baby in high temperatures can be very uncomfortable, especially if it's during the third trimester.
Many women choose a spring baby because it pretty much avoids being pregnant during those summer months and the final trimester happens in winter, which means you'll be wrapped up anyway. Any pregnancy hot flashes will be much easier to handle when it's milder outside.
When to have a baby: your healthDo you suffer from depression, or maybe Seasonal Affective Disorder (SAD)? If you do, then winter could be the most difficult time of year for you, so you may want to avoid having your baby at a time that coincides with that, as the hormonal changes associated with pregnancy can also affect your emotional health.
Spring is another good option for a child, because the main cold and flu season is over by March and April, so both you and your little one will be less likely to pick up something during their very early weeks.
When to have a baby: family situationsWhen does the rest of your family have a birthday? Perhaps you'd like everyone to all have their special day around the same time, or perhaps you want to space them out.
Some people think that it's better to have a child's birthday not coinciding with major holidays or events, such as Christmas, or maybe summer's better because you can go on holiday and celebrate.
All these concerns vary for all families so you can see how things might differ, depending on your situation.
When to have a baby: your workObviously, once you have your baby you go on maternity leave - but have you considered whether your pregnancy might be more difficult at certain times of the year, depending on your job?
If you know that your job requires you to travel more during a busy season, then you might want to avoid being in late pregnancy around then.
Similarly, if your work is influenced by the wedding industry, the summer is bound to be your busiest time and being in full bloom during July and August won't make your job any easier.
Even not having your partner around during the end of the pregnancy might be a factor, so if their career is likely to have a similar effect, think hard about when your baby is likely to be born, and whether you'll have enough support around you at that time.
When to have a baby: your childDepending on what season of the year your child is born, there are scientific patterns that show a child's health can be affected by four different factors:
A woman's hormone levels can vary greatly during pregnancy, depending on what time of year it is. For example, melatonin, the hormone that affects how well we sleep, is influenced by temperature and light levels.
The hormone levels in a woman's body as a child is developing and is born can affect a person's health for the rest of their life.
When to have a baby: the seasons
Asthma is on the rise and those born in spring are most at risk, potentially because viruses that affect breathing are more common at this time of the year. However, it's also said that the brightest babies are often born in springtime!
The high pollen counts during early summer are thought to be the reason for summer-born people being less affected. Mothers will have been pregnant during early summer and antibodies form to reduce the sensitivity.
If you want to have lots of grandchildren, you should know that your baby will be less likely to have a large family if they're born in the summer months. Scientists aren't sure why, but these women consistently have fewer children.
The good news, though, is that the sun obviously has a positive effect on summer-born people, who are happier than winter-born people.
A 2016 study from the University of Southampton showed that children born at this time do have a higher likelihood of developing eczema, but for the most part, being born in autumn is meant to be good for health because mums will have soaked up lots of vitamin D from the summer's sunlight. Vitamin D is important for brain function and is also thought to have long-term health benefits.
Reproductive hormones are higher in pregnant women in summer, so this is thought to lead to autumn babies being born with more eggs and so having a later menopause.
Daylight hours and an increase in vitamin D are linked to winter babies being taller, while the lack of sunshine is thought to be the reason for grumpiness. Research from Germany found that men born between November and January were also significantly more likely to be left-handed than those born during other parts of the year - but they couldn't decipher why...
Scientists have also discovered that winter people tend to be less likely to try extreme sports and prefer comfort and familiarity. Strange but true!