Often these babies are picked up by ultrasound scan and their weight estimated to be ‘under the 3rd centile’ – meaning that if 100 babies were measured at this stage in pregnancy, these babies would be one of the smallest three. These babies have close monitoring with regular ultrasound scans to look for signs of the placenta not functioning properly. Earlier birth with induction of labour or caesarean section may be recommended. This often occurs at 37 weeks but may be needed earlier.
The placenta implants in the first part of pregnancy (before 16 weeks), so medication to improve placental function needs to be taken early. In pregnancies at higher risk of fetal growth restriction taking aspirin 150mg nightly from 12 to 36 weeks reduces the chances of it occurring.
Aspirin reduces the activity of platelets. Platelets are involved in reducing blood supply to the placenta as it implants. Aspirin therefore appears to help the placenta implant better in pregnancies where there is a higher risk of placental problems. It has been shown in high quality clinical trials to reduce the risk of pre-eclampsia and fetal growth restriction.
Aspirin 150mg at night from 12 weeks is safe in pregnancy and recommended in those at higher risk of pre-eclampsia and fetal growth restriction. At this dose it has been shown to have benefits, and there is no evidence of harm to the baby or fetal abnormalities caused by aspirin at this dose.
Aspirin reduces platelet activity, therefore it makes blood a little slower to clot. As blood usually clots quicker in pregnancy this usually doesn't cause any problem. However, there is a small possible increase in bleeding after birth (post partum haemorrhage –PPH) when taking aspirin, so aspirin should be stopped at 36 weeks. If you are taking aspirin during pregnancy and you have multiple bleeds or a large bleed then discuss with your midwife or doctor whether you should continue it.