Has the message on age and fertility gone too far?
Experts fear older women are ditching contraception in the mistaken belief that they cannot get pregnant past a certain age.
BBC News website readers have been giving their views on the story.
This pregnancy been the greatest shock
I'm 38 and seven months pregnant with my third child. Despite falling easily in my early 30s with my two sons, I did expect that my fertility would decline - after all, isn't that the message we are all bombarded with? This pregnancy has been the greatest shock. We didn't want a third child and I had returned to my career at full throttle and now we have to begin the whole process of raising a small baby all over again. Though it has plenty of rewards, it's also pretty tiring not to mention expensive. The fear of the child having abnormalities is also very prominent during this pregnancy, although nothing has been identified I am still very nervous about whether he will be OK or not.
Anon, London, UK
I am 45 and six months pregnant. I thought I was safe and too old to conceive. My children are ten and seven and I had absolutely no intention of another pregnancy, but could not bring myself to go through an abortion. Although I am relatively fit, I feel a real difference with being pregnant at this age and I'm feeling quite scared about the upheaval this will bring to my life.
Dionne, London, UK
At the age of 42 I fell pregnant with identical twin girls. I already had two children aged 12 and eight and assumed, because I hadn't taken or used contraception since the age of 35, that I was past the point in life where I would fall pregnant naturally. My first thought was not to continue with the pregnancy but my husband and I were committed and we felt the babies should be given every chance. I had a healthy pregnancy and our daughters were born at 37.5 weeks. We now feel blessed to have added two beautiful girls to our family. That said, having an age span of 12 years is not ideal, it's like having two separate families and I think is hard on the older children.
Mandy McKinley, Herndon, USA
COMMENTS ON LATE PREGNANCIES
I thought my fertility had declined so much there was no need to use anything. How stupid!
I am shocked! I am one of those women who thinks because I am past 35 years of age I am not going to get pregnant. You hear and read so much about how fertility declines after thirty. I do have three children which I conceived very quickly but since I did have my last child at 33 years, I spent the next two years trying to find a contraceptive that was acceptable to me. I realised I was not getting pregnant so I thought my fertility had declined so much there was no need to use anything. I have not used anything for the last two years ! How stupid of me. Thank you for snapping me out of it.
Voula, Gloucestershire, UK
When we decided to have anther baby I was given advice that because I am 36 and had had an IUD, my chances of conceiving were low. Three weeks after having the IUD removed - two little pink lines appeared on the test! So much for reduced fertility!
Helena, Peterborough, UK
It isn't just women who think one can't get pregnant after a certain age. Doctors do, too. When I was almost 41 I already had two children under three, which I considered quite enough. After a failure with a contraceptive on holiday, I insisted on finding a local GP and asking for emergency contraception. The GP was most unwilling to give it, saying that at my age I was very unlikely to get pregnant.
Claire Richards, Cardiff, UK
"I was in my 40s when I had my fit and healthy children"
I find it unbelievable there are young women in their 30s who think they're too old to get pregnant! I was in my 40s when I had my fit and healthy children. Until a woman has been right through the change, they can still - and do - get pregnant. It's not uncommon for women going through the menopause to get pregnant either - the family "afterthought" who's often younger than his or her siblings.
Jenny, Taunton, UK
I am a sexual and reproductive health expert at a clinic in Addis Ababa. Among the different clients attending my clinic daily, most are seeking contraceptives. Almost all of them are below 34-years-old. At the other end of the spectrum lots of women older than 35 feel shy and ashamed to ask for safe abortion services.
Shimelis Awoke, MD, Addis Ababa, Ethiopia
My wife and I had six attempts at IVF before she became pregnant with our son. My wife will be 44 in April and we are considering trying for another. I don't see a problem in having a baby at this age. We did not meet until she was 38 and before that we did not feel that we were in the right relationships to have children. For people that meet later in life, having children in your 40s is quite normal and may be the only option.
Barry, Maidstone, UK