High Risk Pregnancies
Common complications during pregnancy
Ιt is normal to notice a change in a pregnant woman’s blood pressure during pregnancy. Progesterone (pregnancy hormone) relaxes the walls of the blood vessels, resulting in lower blood pressure during the first and second trimester. Due to the lower blood pressure, dizziness may occur with a tendency to faint particularly after standing for a long time or when standing up abruptly.
Should there be high blood pressure prior to 20 weeks of pregnancy, this is linked to pre-existing hypertension or chronic hypertension. If hypertension develops after the 20th week, then this is known as gestational hypertension.
Should the blood pressure of the expectant mother rise too high, medication may be recommended. Gestational hypertension usually subsides once the baby is born. However, this may take some weeks.
During pregnancy, some women may not produce enough insulin to meet the extra needs of pregnancy. This causes a special form of diabetes called gestational diabetes. If gestational diabetes is identified during the first trimester of the pregnancy, the condition probably existed before the pregnancy.
Obesity, a family history of type 2 diabetes (parent, sibling), previous endometrial death, and/or a large newborn in a previous pregnancy (4.5 kg or more) are among the risk factors for gestational diabetes.
It is diagnosed over three consecutive blood sugar samples after the 24th week of pregnancy, after administering the expectant woman with 75-100 g of pure glucose. Abnormal values in the blood sugar readings indicate the existence of gestational diabetes.
Early diagnosis and appropriate treatment (through diet – intravenous medication) largely ensure the fetus’ health.
Pre-eclampsia is a serious disorder that occurs only during pregnancy. Typically, it occurs after 20 weeks gestation and most likely in the third trimester of pregnancy, after the 27th week.
The condition is characterized by high blood pressure and the presence of protein in the urine. Swelling (on the face and hands), sudden weight gain, headaches, and blurred vision are also important symptoms. The severity of the symptoms usually determines the severity of pre-eclampsia. The earlier the disorder manifests, the more severe the symptoms whereas when it occurs is in the third trimester, the outcome
is better, although, in some rare cases of galloping pre-eclampsia, the symptoms progress rapidly.
Early diagnosis and proper and careful monitoring will ensure the best possible outcome for both mother and child.
A thrombophilia test is recommended to women who suffered from this disorder to allow for better management of a subsequent pregnancy
Any loss of pregnancy within the first 22 weeks of gestation is considered a miscarriage. About 10% of pregnancies end in miscarriage, with more than 80% occurring before reaching 12 weeks of gestation.
Most miscarriages are caused by chromosomal abnormalities of the fertilized egg. The first sign of a miscarriage is usually vaginal bleeding, although it is not uncommon to experience bleeding in early pregnancy even if there is no miscarriage.
If the miscarriage occurs prior to the cardiac function of the fetus, an attempt is made to assist the complete process of miscarriage with medication. If the miscarriage occurs after 7-8 weeks of gestation, then minor surgery is recommended to remove any pregnancy tissue from the uterus. One miscarriage is considered accidental and does not require further investigation. Having 3 or more miscarriages in a row (known as recurrent miscarriages) does require further investigation.
An ectopic pregnancy is when a fertilized egg implants itself outside of the womb, usually in one of the fallopian tubes (the tubes connecting the ovaries to the womb).
An ectopic pregnancy can be treated quickly through laparoscopic removal of the ectopic pregnancy or through a more conservative approach (using medication) provided certain conditions apply.
If an ectopic pregnancy is not promptly treated, the woman runs the risk of internal bleeding in case of rupture of the fallopian tube as the fetus develops.
During pregnancy, the placenta moves as the uterus stretches and grows. Normally the placenta is low in the uterus in early pregnancy and typically moves to the top of the uterus as the pregnancy develops. This position allows for a clear path (through the cervix across the vagina) for natural delivery.
Placenta previa is when, during the last months of pregnancy, the placenta remains low in the uterus and covers part or all of the cervix. During natural delivery, covering the internal cervical os can cause severe bleeding during delivery, endangering both mother and child.
In case of vaginal bleeding with bright red blood, without any other discomfort, during the second half of pregnancy, it is a sign of placenta previa and you should consult your doctor.
It may be mild to heavy bleeding. Bleeding usually stops without treatment, but almost always reoccurs some days or weeks later. Usually, each subsequent episode is more severe.
The position of your placenta is checked during the 20-week ultrasound scan.
Should a placenta previa be determined, the expectant mother is then frequently monitored. The placenta usually corrects itself and by week 28 of gestation, the placenta final position is known. In case the placenta remains low-lying or previa after week 28, it is recommended that the delivery is via a caesarean section.
Placental abruption is when the placenta separates early from the uterine wall before childbirth. Most commonly it occurs in the last 12 weeks of pregnancy and symptoms may include vaginal bleeding, lower abdominal pain, and dangerously low blood pressure.
Placental abruption can be partial or complete. Small detachment is not considered threatening to the mother or fetus and is treated with rest and very gentle activity. Should the detachment be severe, however, the pregnant woman would need to be hospitalized for treatment If the detachment is complete it will lead to endometrial death.
Placental abruption occurs in 1% of pregnancies and is the most common cause of fetal death. Some predisposing factors for the occurrence of placental abruption include the mother’s advanced reproductive age (> 35 years), a history of placental abruption in a previous pregnancy, high blood pressure (hypertension), bumps in the abdomen, and smoking during pregnancy.
In case of fetal death due to placental abruption, it is recommended for the mother to do a thrombophilia test for better management of any subsequent pregnancy
Childbirth likely to occur prior to completion of 37 weeks gestation is considered a threatened premature labour. Some of the symptoms include regular and painful contractions less than 10 minutes apart lasting for more than an hour, dilation, discharge of mixed blood and mucus, and disappearance of the cervix.
The survival of premature infants/ preemies/ neonates to a large extent depends on the gestational age. It is around 15%-30% at 24 weeks gestation and increases progressively to over 95% after 32 weeks gestation.
Premature birth at less than 27 weeks gestation is linked to neurodevelopmental disorders, cerebral palsy, hemiplegia, etc. Most premature infants, delivered before the completion of 32weeks and those
weighing less than 2kg, require respiratory support and are hospitalized at a neonatal intensive care unit (NICU) until they have developed sufficiently to survive on their own. Babies born between 32 and 37 weeks will need standard care at a specialised neonatal care unit.
Factors that increase the risk of premature labour before 34 weeks of gestation include:
- The Mothers physiology and characteristics (age, height, nationality)
- The Mothers pregnancy history
- Multiple pregnancies (two or more fetuses)
- Pregnancy-related conditions such as pre-eclampsia, residual fetal development, gestational diabetes
- Uterus congenital anomalies (septate uterus)
- Cervical weakness or incompetence
- Some infections, particularly of the amniotic fluid and lower genital tract
The chances of preventing premature labour in symptomatic women (experiencing contractions) or in women with predisposing factors are relatively limited.
Some methods to prevent premature delivery include Cervical cerclage, use of progesterone, use of Cervical pessary depending on the cause of the premature delivery.
Cervical insufficiency (also known as incompetent cervix) is one of the causes of miscarriage or premature birth. It means that the woman’s cervix dilates too early during pregnancy, usually without pain or contractions.
Normally, during pregnancy, the cervix stays firm and closed until late in the third trimester. It opens, shortens, and gets thinner and softer so the baby can pass through the birth canal during labor and birth. When, in some women, the cervix opens too early during pregnancy or is shorter than normal, the cervix is considered deficient.
Usually, cervical insufficiency may go unnoticed by the pregnant woman as there are no specific symptoms. The diagnosis is usually made by the doctor during the ultrasound examination at the end of the first trimester when the length of the cervix and cervical transparency is measured and the morphology of the cervix is assessed.
As cervical insufficiency increases the risk of premature birth (especially during the second trimester resulting in either death of the fetus or increased morbidity), should the doctor identify a case of cervical insufficiency or if there a history of it, the pregnancy will be more closely monitored through frequent ultrasound scanning and treatment, depending on the condition of the cervix.
If the length of the cervix is 15-25 mm, it is treated with daily administration of progesterone, either orally or intravaginally, in the form of a tablet that is placed vaginally or in the form of a gel. According to studies, the administration of progesterone seems to have good results. Frequent ultrasound evaluation of the cervix is of course necessary.
In cases where the length of the cervix is below 15mm or if, during monitoring, the doctor identifies that the cervix continues to rapidly decrease in length, then a cervical cerclage is performed (also known as a cervical stitch). This means that a strong suture is sewn into and around the cervix and this tightens the cervix and protects it from dilation if there are no contractions. Pregnant women with cervical insufficiency should refrain from strenuous physical activity and rest as much as possible. Sexual intercourse is also prohibited. The cervical stitch is removed towards the end of the pregnancy when the greatest risk of miscarriage or premature birth has passed (either when there are contractions that will lead to childbirth, or in the 37th week).
An embryo may not grow properly if it is not getting the oxygen and nutrients it needs.
Below are the three primary causes of intrauterine growth retardation:
- Placenta-related causes: The placenta is not functioning properly so the exchanges
between the fetus and the mother are not normal.
- Causes associated with the mother’s condition: severe anemia, smoking, alcoholism, heart disease, etc.
- Fetus-related causes: infections or chromosomal abnormalities such as trisomy 21, trisomy 18, etc.
The most common cause of intrauterine fetal development is placental insufficiency (approximately 75% of cases).
Infants with under-development have very low levels of oxygen and nutrients and an increased chance of dying in utero. Frequently they are unable to sustain a vaginal birth and for this reason, a caesarean section is necessary for delivery. At birth, they are more likely to have hypoglycemia, hypothermia, jaundice, respiratory problems, and are more susceptible to infections.
In such cases, the pregnant woman undergoes an ultrasound every 2 to 3 weeks in order to monitor the size of the fetus and its growth rate and to calculate the amount of amniotic fluid. Furthermore, a cardiotocograph and a Doppler ultrasound should be frequently performed (to monitor blood flow to and from the fetus). The goal is for the fetus to remain in the mother’s womb for the longest possible without
compromising the health of either the mother or the fetus.
In cases of residual fetal development, a thrombophilia test is recommended for better management of any subsequent pregnancy.
By multiple pregnancy we refer to the simultaneous gestation of more than one fetus (two embryos-twin pregnancy, three embryos-triplet pregnancy, etc.). Twin pregnancies can be dizygotic (when two fertilized eggs are implanted in the uterus) or monozygotic (when the two embryos come from the division of one fertilized egg). Monozygotic embryos are identical to each other and are much rarer than dizygotic twins. The use of drugs to induce ovulation, the application of in vitro fertilization (IVF), and the increase in pregnancy of women over the age of 35 have increased the incidence of multiple pregnancies.
The risk of complications is higher in multiple pregnancies compared to a single pregnancy and the risk increases as the number of fetuses increase. For this reason, during a multiple pregnancy, the pregnant woman undergoes special and increased monitoring.
The most common complications of multiple pregnancies include:
- Premature Labour
- Loss of one or more embryos
- Abnormalities in the development of the fetus
- Gestational hypertension
In the case of Monozygotic twins, the pregnancy faces additional risks as any of the following complications may occur:
- Selective growth restriction (FGR): In 10% of monochorionic twins, placental mass is unevenly distributed between embryos. As a result, one of the two babies is significantly smaller, often from the beginning of pregnancy.
- Fetal – Fetal Transfusion Syndrome: In the placenta of monochorionic twins there are vessels – anastomoses on the surface of the placenta. Through these vessels there is an uneven distribution of blood between the two embryos, with one embryo receiving much more blood than the other. As a result, there is a difference in amniotic fluid with the older baby having increased amniotic fluid and the younger baby having very little fluid.
- Embryonic loss of one of the 2 embryos: Due to the vascular anastomoses between the embryos, the well-being of one embryo depends directly on the other. So should there be an unpleasant development of intrauterine loss of one baby, there is a significant risk of loss or disability (mainly neurological) also of the other baby.
- Structural abnormality: There is a significant risk of structural abnormality in monochorionic twins, with 4% of cases involving only one of the two embryos.
Gestational trophoblastic disease (GTD) is a term used for pregnancy-related tumours. These tumours are rare, and they appear when cells in the womb start to multiply uncontrollably.
The trophoblast is the initial cell formation, formed before the embryo is even formed. This cell formation swells and multiplies rapidly and occupies the uterine cavity.
There are four types of gestational trophoblastic disease (GTD):
- Hydatidiform mole (complete or partial) – benign in most cases
- Invasive mole (malignant)
- Choriocarcinoma (malignant)
- Placental-site trophoblastic tumor (malignant)
Complete or partial Hydatidiform moles account for 90% of GTD cases and are usually benign forms of the disease. Hydatidiform moles are abnormal conceptions with excessive placental development. Conception takes place, but placental tissue grows very fast, rather than supporting the growth of a fetus. Partial hydatidiform moles are the only ones where there is a fetus or fetal cells.
At the initial stages of GDT, the symptoms are the same as in early pregnancy: the patient has a delay in her period, feels nauseous, vomits, and has a positive pregnancy test. During the ultrasound examination, however, having abnormally swollen cells around the fetus (the chorionic villi) and blood tests indicating very high levels of β-chorionic gonadotropin, would indicate the presence of GTD. GTD tumors are usually diagnosed in women under the age of 20 or over the age of 40. Women who have had GTD in the past are at a slightly higher risk for the disease to be reactivated. The treatment consists of the removal of the pathological tissue from the uterus by suction curettage and the tissue is sent for histopathological examination, in order to decide on further treatment. Most cases of the trophoblastic disease can be cured, and women retain their fertility for future pregnancy. In all cases, it is recommended to take contraceptive treatment for the next 6 months.
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Pregnancy can be a stressful and emotionally challenging time for many families. We have the expertise and resources to help, whether you have an underlying medical condition, problems with poor pregnancy outcomes, or a suspected or known problem with your baby (fetus). Feel free to come and ask us.
Detection of High Risk Pregnancies
The doctor at the first appointment collects the patient’s medical history for the prevention of possible complications. Below are the most important considerations:
- Age (over 40 years old)
- Family history of congenital anomalies or previous child with genetic abnormalities
- History of recurrent miscarriages, endometrial death
- History of residual fetal development, preeclampsia
- History of cervical insufficiency, premature birth
- History of pregnancy-related complications such as gestational diabetes
- Pre-existing diseases such as heart disease, hypertension, diabetes, thyroid disease, etc.