Many will let pregnant women go up to two weeks over. After 42 weeks, however, the baby's health might be at risk. A very small number of babies die unexpectedly if they are still in the womb beyond 42 weeks of pregnancy.
Almost all babies are born within three or four weeks of the due date. If a baby hasn't been born by then, the risk of being stillborn (dead at birth) increases. Babies are very rarely born that late, though, because labor is usually induced two weeks after the due date at the latest.
Pregnancy is considered to be “full-term” at 40 weeks (or 280 days). A pregnancy that continues for longer than 42 weeks is called a post-term, prolonged or overdue pregnancy. If the mother and baby are both doing well, being up to one week “late” isn't associated with any particular risks for either of them.
Complications of being overdue
If your pregnancy goes overdue, there is a risk that the placenta won't function well enough to supply your baby with oxygen and nutrients. The risk of stillbirth or neonatal death gets higher the longer you go overdue.
Your doctor or midwife might recommend induction of labour in these situations: You're 41 weeks pregnant or more. You have health concerns, like high blood pressure or pre-eclampsia. Your baby is unwell or there are other concerning signs – for example, changes to your baby's heart rate or your baby not growing well.
Induction is offered in longer pregnancies because, after 41 weeks, there is a higher chance of a baby being admitted to a neonatal intensive care unit, and the rate of stillbirth increases from less than one in 1,000 at 40 weeks to three in 1,000 (Middleton, 2020; NICE, 2021a).
You at 42 weeks
There's a higher risk of stillbirth if you go over 42 weeks pregnant, although most babies remain healthy. At the moment, there's no way to reliably predict which babies are at increased risk of stillbirth, so induction is offered if you do not go into labour by 42 weeks.
Investigators at Lenox Hill Hospital, in partnership with Sweden's Karolinska Institute, recently found that, on average, males spent about one day longer in the womb than females.
By age 30, fertility (the ability to get pregnant) starts to decline. This decline happens faster once you reach your mid-30s. By 45, fertility has declined so much that getting pregnant naturally is unlikely.
When a pregnancy reaches 42 weeks and beyond, it's postterm. Late-term and postterm pregnancy can raise the risk of some health problems, including: Larger than average birth size (fetal macrosomia). This increases the chance that you may need forceps, a vacuum device or another instrument to assist with the birth.
Spending most of your time in bed, especially lying on your back, or sitting up at a small angle, interferes with labor progress: Gravity works against you, and the baby might be more likely to settle into a posterior position. Pain might increase, especially back pain.
Your provider may recommend inducing labor if: Your pregnancy lasts longer than 41 to 42 weeks. After 42 weeks, the placenta may not work as well as it did earlier in pregnancy. The placenta grows in your uterus (womb) and supplies your baby with food and oxygen through the umbilical cord.
A normal cycle can be between 21 to 35 days, and some people can even have cycles that range outside of that. Regularity isn't that common, so there's a fair chance that the calculation will be off, but the last menstrual period measurement is still used because it's considered fairly reliable most of the time.
The truth is your baby's sex has very little to do with the length of pregnancy.
The longest recorded human pregnancy was 375 days, or just over 12 and a half months, according to Guinness World Records. During this pregnancy, a woman named Beulah Hunter gave birth to a healthy baby girl in 1945.
Getting up and moving around may help speed dilation by increasing blood flow. Walking around the room, doing simple movements in bed or chair, or even changing positions may encourage dilation. This is because the weight of the baby applies pressure to the cervix.
Most pregnancies last 37 to 42 weeks, but some take longer. If your pregnancy lasts more than 42 weeks, it is called post-term (past due). This happens in a small number of pregnancies. While there are some risks in a post-term pregnancy, most post-term babies are born healthy.
It's your choice whether to have your labour induced or not. If your pregnancy lasts longer than 42 weeks and you decide not to have your labour induced, you should be offered increased monitoring to check your baby's wellbeing.
Researchers now believe that when a baby is ready for life outside his mother's uterus, his body releases a tiny amount of a substance that signals the mother's hormones to begin labor (Condon, Jeyasuria, Faust, & Mendelson, 2004). In most cases, your labor will begin only when both your body and your baby are ready.
Side-lying with upper knee bent
It's OK to lie down in labour. Lie down on one side, with your lower leg straight, and bend your upper knee as much as possible. Rest it on a pillow. This is another position to open your pelvis and encourage your baby to rotate and descend.
When you reach between 41 and 42 weeks, the health risks to you and your baby become even greater. Your provider will likely want to induce labor. In older women, especially older than 40, it may be recommended to induce labor as early as 39 weeks.
Research indicates that inducing labor at this time reduces several risks, including risks of having a stillbirth, having a large baby (macrosomia) and developing high blood pressure as the pregnancy advances.