Advanced Pregnancy and Risks

An increase has been observed in the number of expectant mothers having their first pregnancy in their advanced ages all over the world, mainly in the developed countries, in the last ten years.

Women’s taking their education to advanced stages and being employed in the same areas as men in occupational life, development of effective birth control methods, evacuation’s becoming legally allowed  and advanced infertility (barrenness) treatment methods contribute to this greatly. 

According to a statistics from the USA, whereas the ratio of delivery by women over the age of 35 among all deliveries was 5% in 1982, this ratio is predicted to be 9% in 2001. The same statistics found that whereas 9% of women aged 35 did not have any children in 1970, this ratio was 20% in 1989.

In the medical literature, fecundability and child bearing in women are the same as the term “fertility”. Again the same term (fertility) is used to refer to the “ability to impregnate” in men.

Pregnancy rates (child bearing, fertility) decrease with advanced age due to biological reasons. Whereas the chance of becoming pregnant in any month is 20% for individuals under thirty, this chance is predicted to be only 5% in individuals over 40.

Whereas the chance of becoming pregnant decreases over the age of 40 even in advanced infertility treatments like tube baby, the risk of miscarriage or a baby with anomalies increases.

These changes in fertility can be explained by the medical condition of the individual, changes in the ovulation function and changes in the structure of the ovum discharged from the ovary.

Furthermore, many women might go through infections relating to female reproductive organs, ectopic pregnancy, appendicitis, endometriosis or surgical intervenion that might affect her reproductivity until the age of forty.

While infertility tests for couples willing to have a child begin after 1 year of failed attempts at becoming pregnant, this period must be 6 months for women over 40.

Medically advanced maternal age:

The important this is that women must be aware that age has an influence on a healthy pregnancy and the potential to become pregnant. The most suitable childbearing age for women is, in fact, between the ages of 18 and 24.

The term “Advanced Maternal Age” in medicine is used to define expectant mothers that become pregnant at the age of 35 and over. Whether it is the first pregnancy  of the woman or not is not included in the definition.

It should be remembered that a sudden sharp increase does not take place in the undesired conditions with regard to the expectant mother and the fetus after the age limit of 35 is exceeded. On the contrary, a linear increase in risks is usually comes into question with increasing age.

Advanced maternal age is accompanied by:

Conditions that concern the expectant mother:

It is a medically known reality that the probability of emergence of diseases like diabetes or hypertension increases with increasing age.

In the case that an expectant mother has pregnancy at later ages, the increase in risk relating to her is more closely related with the presence or absence of chronical diseases in her when the pregnancy started than the numerical character of her age. Probability of appearance of a chromosomal abnormality (like Down Syndrome), on the other hand, shows direct correlation with age.

Therefore, it being possible in general terms to say that greater dangers await expectant mothers in advanced ages, it is not possible to say that the same increase in risks is in question for every individual.

The damage a chronical disease gives to the body is directly related to the period the disease exists in the body. Therefore, the probability of emergence of undesired conditions during pregnancy increases as the age, in which the individual with a chronical disease becomes pregnant, increases. The best example to this is Type 2 diabetes. The damage uncontrolled increase in the blood sugar gives to the veins as the duration of the disease, which appears more frequently especially after the age of 40, grows longer.

Diseases Frequently Observed in Those With Advanced Maternal Age:

Hypertension :

Chronic hypertension is observed 2 to 4 times more often in pregnancies over the age of 35 than in earlier pregnancies and the approximate rate of incidence is 10%. Gestational (pregnancy induced) hypertension observed in advanced gestational age in the final periods of pregnancy is usually evaluated as a finding of chronical hypertension. Such hypertension experienced towards the end of pregnancy  is not expected to pose a great risk for the expectant mother and the fetus as long as preeclampsia does not develop. However, whether the hypertension disappears at the end of pregnancy must be necessarily examined.

Chronic hypertension, especially one that has existed for a long time and caused vascular damage, might pose a risk both for the mother and the fetus. The actual risk is superimposed (developed due to chronic hypertension) preeclampsia which might appear in expectant mothers with chronic hypertension.

If expectant mothers becoming pregnant in advanced age do not have chronic hypertension, the probability that they will develop preeclampsia is the same as those becoming pregnant at a younger age. In other words, age does not increase the risk of pregnancy induced preeclampsia in an expectant mother with no hypertension.

Diabetes:

Frequency of Type II Diabetes increases with age. Accordingly, prevalence of Type II Diabetes and undesired conditions due to the disease increases twofold or three fold in pregnancies at an advanced age when compared to pregnancies at a young age.

Gestational diabetes (pregnancy induced diabetes) is directly proportional with age and increases in prevalence  in pregnancies at an advanced age.

Diabetes that has been existing for a long time and progresses in an uncontrolled manner might pose risks for the expectant mother and especially for the fetus.

Other diseases :

An increase in the prevalence of cardiovascular diseases, neurological diseases, kidney, liver, lung and connective tissue diseases and cancers with increasing age. Existence of these diseases might have an adverse effect on the progress of the pregnancy in pregnancies at advanced ages.

Conditions such as deep venous thrombosis, pulmonary edema that risk the life of the mother are observed more often in expectant mothers at advanced ages, especially in those that have a chronic disease.

Undesired conditions relating to pregnancy and delivery in mothers with an advanced age:

Miscarriage :

Risk of a pregnancy formed ending up in miscarriage displays a linear increase with increasing age. About  fourfold increased risk of miscarriage is in question in pregnant women over 35 when compared to the younger ones. The most important reason for that is the increase in the probability of existence of chromosomal abnormalities in the production of conception with increasing age. Chromosomal abnormalities are among the most significant reasons of miscarriages.

Ectopic Pregnancy:

The risk of appearance of ectopic pregnancy increases twofold or threefold in advanced age when compared to pregnancies at young ages. This might result from the slowdown in the tubal mobility due to age itself. Damage to the tubes caused by a large number of previous pelvic infections might also be a significant factor.

Appearance of Anomalies in the Fetus:

Advanced maternal age increases the risk of appearance of chromosomal anomalies in the fetus. Anomalies such as Down Syndrome that are directly related to age display an exponential (displaying an increase that is higher than the age increase) rather than a linear increase especially after the age of 30. Risk of appearance of structural anomalies (anomalies concerning the body shape or organs of the fetus), on the other hand, are probably the same in all age groups.

Preterm Delivery

Preterm delivery is observed more often in pregnancies during advanced ages. Age is not only a risk factor for spontaneous preterm delivery activity and preterm birth but also it is an important risk factor for induction (initiation of the delivery activity by the doctor) performed due to existence of conditions threatening the life of the mother. This is why preterm delivery is observed fourfold more often in pregnancies at advanced ages.

Intrauterine Growth Restriction (IUGR):

Risk of appearance of intrauterine growth restriction (IUGR) is twofold or threefold higher in pregnancies at advanced ages. Risk of development of IUGR is higher especially for expectant mothers with hypertension and/or diabetes.

Bleeding During Pregnancy :

Risk of appearance of bleeding due to placenta previa and ablatio placento especially in the later stages of pregnancy has increased in pregnancies at advanced ages.

These conditions are not thought to increase due to age factor only for ablatio placenta is a condition observed especially among pregnant women with hypertension and prevalence of chronic hypertension is higher in pregnancies at advanced ages. Therefore, ablatio, which is frequently observed 1/200 during pregnancy, is observed at the ratio of 3% especially among pregnant women over 40.

Placenta previa is observed more often among expectant mothers of advanced age especially those who have been through many pregnancies probably independent from the age factor as it is a condition that is directly related to pregnancy and number of deliveries.

Problems relating to the fetus and the newborn:

Conditions such as IUGR, preeclampsia and diabetes in the expectant mother might lead to appearance of conditions on a spectrum ranging from uteroplacental deficiency and resultant fetal distress to fetal asphyxia to newborn asphyxia resulting in conditions ranging from neurological disabilities to the death of the baby.

Preterm delivery and IUGR are the two most significant conditions that require intensive care treatment for the baby in the newborn and result in the death of the baby in heavy scenes.

Problems related to delivery:

All stages of the delivery action last longer especially in elderly expectant mothers experiencing their first pregnancy. Shoulder dystocia might appear in the baby of an expectant mother carrying a large baby during delivery.

All the above reasons cause an approximately twofold increase in the cesarean delivery rate in pregnancies at advanced ages as the life of the mother or the baby is at risk.

Necessity for hospitalization during pregnancy:

Necessity for hospitalization is twofold or threefold higher in the antenatal period (before delivery) compared to other pregnancies due to both examination and treatment of previously existing diseases such as hypertension or diabetes and the increase in the probability of appearance of undesired conditions during pregnancy (like bleeding or threatened preterm labor).

Maternal Mortality and Child Deaths:

Maternal death during pregnancy, delivery or puerperality are decreasing with every passing day today. Cases of death which were considered as “tragic destiny” previously are decreasing day by day thanks to the advancements in medical science and medical technology.

Although pregnancy induced cases of death decrease and nearly come to an end, they will probably not end in any stage of civilization. Probability of death of the mother during delivery or puerperality due to pregnancy or as a result of the bad course of a disease the mother carries to the pregnancy is fourfold higher in pregnancies at advanced ages when compared to pregnancies in young ages. Therefore, death due to various reasons occurs in six out of 10,000 pregnancies at advanced ages. 

The fourfold risk difference between maternal deaths in the advanced and young ages remains stable as the decrease in maternal death due to the advancements in science and technology is reflected equally on all pregnancy age groups.

Risk of death of the babies of expectant mothers at advanced ages due to any reason is only 1.5 times higher than that of the young expectant mothers. The reason why the difference is so small is the fact that the technological and scientific means of newborn intensive care units have developed rapidly in the recent years. 

However, the risk of death for the babies of mothers over 35 increases in the newborn (the first 30 days after birth) and infancy (the first year after birth) periods increases obtrusively. The numerical ratio and reasons of this is not known exactly.

Economic aspect of advanced maternal age:

Pregnant women with advanced maternal age go through more antenatal controls and more examinations when compared to pregnancies at young ages even if she carries no diseases to pregnancy.

Appearance undesired conditions during the course of the pregnancy, cesarean delivery and requirement of care under intensive care conditions for the newborn baby for a long period due to preterm delivery in worse conditions increases the cost of examinations and treatment to a significant extent.

In short, the cost of pregnancy at advances ages is higher than pregnancy at young ages.

Precautions To Be Taken :

However much pregnancies at advanced ages carry more risks precautions to be taken on this matter are available. Amniocenteses and chorion villus sampling (CVS), which are prenatal diagnosis methods, are effectively used to detect chromosomal abnormalities that might occur in the babies of mothers with advanced maternal ages.