Every pregnancy carries its risks, but with good prenatal care and support those risks can be minimized. There are some factors, however, such as age and overall health which increase a woman’s chances of complications during pregnancy.
Structural problems in a woman's uterus or cervix heighten the risk of difficulties, including miscarriage, an abnormally positioned fetus, and difficult labor. These problems also increase the risk of a cesarean delivery.
Age is one of the most common factors that can hinder a woman's pregnancy.
Women under the age of 20 have a significantly higher risk of serious medical complications related to pregnancy than those over 20. Children born to teenage mothers are more likely to deliver prematurely, have a low birth weight, develop placenta previa, experience pregnancy-induced hypertension, and contract toxemia. Some risk factors connected to young age include:
- Underdeveloped pelvis. Young women's bodies are still growing and changing. An underdeveloped pelvis can lead to difficulties during childbirth.
- Nutritional deficiencies. Young women are more likely to have poor eating habits. Nutritional deficiency can lead to extra strain on the body that causes more complications for both the mother and child.
- High blood pressure. High blood pressure can trigger premature labor, which can lead to premature and/or underweight babies who require specialized care to survive.
Women over 35
As a woman ages, her chances of conceiving begins to decline. An older woman who becomes pregnant is also less likely to have a problem-free pregnancy. Common issues include:
- Underlying conditions. Older women are more likely to have conditions such as high blood pressure, diabetes, or cardiovascular disease that can complicate pregnancy. When these conditions are not well controlled, they can contribute to miscarriage, poor fetal growth, and birth defects.
- Chromosomal problems. A woman over 35 has a higher risk of having a child with birth defects due to chromosomal issues. When a woman is age 35, her chance of having a baby with a genetic disease is one in 178; by age 48, the chance rises to one in eight. Down syndrome is the most common birth defect related to chromosomes; it causes varying degrees of mental retardation and physical abnormalities. Prenatal screening and tests can help determine the likelihood of chromosomal complications.
- Miscarriage. A woman age 35–39 is twice as likely to have a miscarriage as a woman in her 20s. About 35 percent of pregnancies end in miscarriage for women age 40–44. The risk increases to more than 50 percent at age 45.
- Other complications. Women over 35 are more likely to have complications commonly associated with pregnancy regardless of age.
Women who are obese (defined as having a Body Mass Index of 30 or over) are at a higher risk than normal-weight women of having babies with some birth defects, including spina bifida, heart problems, hydrocephaly, and cleft palate and lip. Obese women are also more likely to be diagnosed with gestational diabetes during the pregnancy. Obese women are also more likely to have high blood pressure, which can lead to a smaller than expected baby as well as increase the risk for pre-eclampsia and toxemia.
Women who weigh under 100 pounds are more likely to deliver prematurely, and/or give birth to an underweight baby.
Both type 1 and type 2 diabetics may experience complications during pregnancy. Poor control of diabetes can increase the chances of birth defects in the baby, and can cause health concerns for the mother as well.
Some women who may not have had diabetes before the pregnancy may be diagnosed with diabetic symptoms during pregnancy. This is called gestational diabetes—any woman diagnosed with gestational diabetes should talk with her doctor about the specific recommendations to control her blood sugar. Dietary changes will be recommended as will monitoring blood sugar levels.
Some women may have to take insulin to control their blood sugar levels. Women who have gestational diabetes are at much higher risk for developing diabetes after their pregnancy is over so testing for diabetes once the pregnancy is over is recommended.
Every pregnant woman should be screened for STIs (including Chlamydia, gonorrhea, hepatitis B, HIV, and syphilis) during her first prenatal visit. A woman who has an STI is very likely to transmit the infection to her baby. Depending on the infection, a baby born to a woman with an STI is at a higher risk for:
- low birth weight
- neonatal sepsis (infection in the baby’s blood stream)
- neurologic damage
- acute hepatitis
- chronic liver disease
A woman who has had five or more previous pregnancies is more susceptible to abnormally quick labor and accompanying excessive blood loss during future labors.
Complications arise in multiple birth pregnancies because more than one baby is growing in the womb. Because of the limited amount of space and the additional strain multiple fetuses put on a woman, these babies are more likely to arrive prematurely. All pregnancy complications, such as high blood pressure and diabetes, are more common in multiple pregnancies.
If a woman has had complications in a previous pregnancy, she may be more likely to have the same complication in subsequent pregnancies.