**5.4. Growth abnormalities**

In mothers older than 40, small and large for gestational age babies and intrauterine growth restriction (IUGR) are increased [79, 80]. Small-for-gestational-age babies (SGA) and IUGR are assumed to be due to placental dysfunction, whose incidence increases with age.

One study found in a very large twin cohort that advanced maternal age was indirectly associated with SGA babies. However, when SGA was present in an older mother, neonatal mortality increased compared to appropriate-for-gestational-age twins in the same age range [81], maybe suggesting an increased severity of the syndrome in this women.

Although it may look as a contradiction, foetal macrosomia also seems to increase with age. It has been suggested that this increased incidence in large-for-gestational-age babies might be due to an overall increase in the body mass index with age [82] and an increased risk of gestational diabetes. However, as we previously mentioned, the increased birth weight in twin pregnancies associated with gestational diabetes could be beneficial for the twin pair, or at least not as detrimental as it could be in singletons.

#### **5.5. Post-partum haemorrhage**

Most protocols worldwide recognise maternal age as an independent risk factor for >10,000 mL blood loss during delivery and for post-partum haemorrhage, in both vaginal and caesarean births. Mechanisms behind this increased risk are not well established. Most doctors working in a labour ward are persuaded that uterine atony is somehow more common among older mothers, although there is no evidence for that. Age is associated with certain obstetric complications, such as hypertensive disorders, placental abnormalities, or preterm birth. On the other hand, advanced maternal age increases the risk of induction of labour, large foetuses for gestational age, prolonged labour, oxytocin augmentation, or caesarean delivery. All of the above are well known risk factors of post-partum haemorrhage [83, 84]. So age may not act as a completely independent factor for post-partum haemorrhage. Results from the WOMAN trial showed an adjusted odds ratio of peripartum hysterectomy of 5.98 (95% CI: 3.34–10.70) for women between 30 and 39 years and of 11.73 (95% CI: 6.30–21.85) for women aged ≥40 [85]. This is a trend shown to be repeated worldwide [86]. Advanced maternal age does not only increase the risk of excessive bleeding but also its severity and the risk of needing aggressive treatment strategies, such as hysterectomy.

Again, twin pergnancy is also associated with a higher risk of post-partum haemorrhage. At the same time, twin pregnancy is often associated with other post-partum haemorrhage risk factors, such as preeclampsia, caesarean delivery, and the use of a caesarean delivery for a preterm delivery [87]. Delivery in this group of patients should be undertaken in tertiary hospitals by trained staff.

## **5.6. Venous thrombosis**

pregnant population [70]. Given the importance of early treatment, all twin pregnancies, as well as in the case of advanced maternal age, first trimester screening should be considered,

In mothers older than 40, small and large for gestational age babies and intrauterine growth restriction (IUGR) are increased [79, 80]. Small-for-gestational-age babies (SGA) and IUGR are

One study found in a very large twin cohort that advanced maternal age was indirectly associated with SGA babies. However, when SGA was present in an older mother, neonatal mortality increased compared to appropriate-for-gestational-age twins in the same age range [81],

Although it may look as a contradiction, foetal macrosomia also seems to increase with age. It has been suggested that this increased incidence in large-for-gestational-age babies might be due to an overall increase in the body mass index with age [82] and an increased risk of gestational diabetes. However, as we previously mentioned, the increased birth weight in twin pregnancies associated with gestational diabetes could be beneficial for the twin pair, or

Most protocols worldwide recognise maternal age as an independent risk factor for >10,000 mL blood loss during delivery and for post-partum haemorrhage, in both vaginal and caesarean births. Mechanisms behind this increased risk are not well established. Most doctors working in a labour ward are persuaded that uterine atony is somehow more common among older mothers, although there is no evidence for that. Age is associated with certain obstetric complications, such as hypertensive disorders, placental abnormalities, or preterm birth. On the other hand, advanced maternal age increases the risk of induction of labour, large foetuses for gestational age, prolonged labour, oxytocin augmentation, or caesarean delivery. All of the above are well known risk factors of post-partum haemorrhage [83, 84]. So age may not act as a completely independent factor for post-partum haemorrhage. Results from the WOMAN trial showed an adjusted odds ratio of peripartum hysterectomy of 5.98 (95% CI: 3.34–10.70) for women between 30 and 39 years and of 11.73 (95% CI: 6.30–21.85) for women aged ≥40 [85]. This is a trend shown to be repeated worldwide [86]. Advanced maternal age does not only increase the risk of excessive bleeding but also its severity and the risk of needing aggressive treatment strategies, such

Again, twin pergnancy is also associated with a higher risk of post-partum haemorrhage. At the same time, twin pregnancy is often associated with other post-partum haemorrhage risk factors, such as preeclampsia, caesarean delivery, and the use of a caesarean delivery for a preterm delivery [87]. Delivery in this group of patients should be undertaken in tertiary

assumed to be due to placental dysfunction, whose incidence increases with age.

maybe suggesting an increased severity of the syndrome in this women.

although there is no international agreement [78].

at least not as detrimental as it could be in singletons.

**5.4. Growth abnormalities**

108 Multiple Pregnancy - New Challenges

**5.5. Post-partum haemorrhage**

as hysterectomy.

hospitals by trained staff.

The incidence of deep venous thrombosis is increased three times during pregnancy. Pulmonary embolism may occur in 1 in every 1000 pregnancies and represents the leading non-obstetrical cause of maternal death [88]. Both age older than 35 years and multiple pregnancy are listed as risk factors for venous thromboembolism. If we consider that the presence of thrombophilia is more common in women undergoing IVF and that deep venous thrombosis is also more common in these women [89, 90], we could conclude that women of advanced maternal age and carrying a multiple pregnancy definitely represent a high-risk group for venous thromboembolism. Under any other risk factor, thromboprophylaxis should be considered carefully.
