These findings might seem counterintuitive as we often associate colder, darker months with worsening mental health, especially for those with seasonal affective disorder - linked to lack of light and Vitamin D exposure.
But the research found that having a child with a birthday in this half of the calendar actually goes some way to “protecting” mothers against the illness.
The study did not explore the reason for this difference but the research team from Brigham and Women’s Hospital, Boston, US, theorised that this is could be because regardless of when your baby is born, new mothers will find themselves spending more time at home.
During the summer this could leave you feeling alone and distanced from social activities that require time spent outside.
Whereas in the winter, it is more seasonally appropriate to spend lots of time at home, and have people visiting you.
Additionally, friends and family are less likely to have holidays abroad booked, meaning they rally around with greater psychological support in the colder months, according to the team.
The research, which reviewed medical records of over 20,000 women, wasn’t just looking at time of delivery, but many other factors including race, pregnancy duration, and mother’s weight, that can increase likelihood of PND.
Jie Zhou, lead study author, said: “We wanted to find out whether there are certain factors influencing the risk of developing postpartum depression that may be avoided to improve women’s health both physically and mentally.”
They also found that the longer your pregnancy lasts, the less likely you are to suffer PND.
“It is expected that the mother will do better and be less mentally stressed when delivering a mature, healthy baby,” said Zhou.
Not having anaesthesia (such as an epidural) during delivery also increases your risk, possibly because the pain associated with labour may have been traumatising.
There was no link between delivery mode and risk factor. Caucasian women also had a lower risk compared to women of other races.
And women with a higher body mass index (BMI) were more likely to suffer with postnatal depression because they required more outpatient follow-ups and had more pregnancy-related complications, affecting their maternal outlook.
Postnatal depression, which affects 10% of women in the UK within a year of giving birth, is classified by the NHS as a “common” type of depression. It can also affect fathers and partners, although this is less common.
Symptoms are a persistent feeling of sadness and low mood, lack of enjoyment and interest in the wider world, lack of energy and feeling tired all the time, difficulty bonding with your baby and withdrawing contact from other people.
Although this can just be ‘baby blues’ which is a short-term feeling of low mood that can last up to two weeks after delivery. If your symptoms have persisted for longer than this, then you might have postnatal depression.
“It’s very hard to bare your soul to people you don’t know very well,” she said.
“Take someone with you to an appointment who you can trust or, if you can’t say the words, write it down and give it to the healthcare professional.”
Useful websites and helplines:
- Mind, open Monday to Friday, 9am-6pm on 0300 123 3393
- Samaritans offers a listening service which is open 24 hours a day, on 116 123 (UK and ROI - this number is FREE to call and will not appear on your phone bill.)
- Get Connected is a free advice service for people under 25. Call 0808 808 4994 or email: firstname.lastname@example.org