Lindsey Graham, Republican of South Carolina, proposed a national ban on abortions after 15 weeks of pregnancy. There is a growing number of women who are having children in their 30's.

The proposed ban would allow exceptions to save a woman's life, but it doesn't include exceptions for fetal abnormality. As such, it would sharply restrict options for the growing number of older women with pregnancies that are long- delayed and much wanted, but also come with a greater risk of Down syndrome.

The median age of children to be born in the United States has increased in the last 25 years. Older mothers are more likely to have a baby with a chromosomal abnormality than younger mothers, and the test most commonly used to detect it can only be done after 15 weeks.

Fetal anomalies can't be diagnosed until after the baby is born. Older mothers are more likely to give birth to a baby with health conditions that can get worse as the baby gets older, so they may need to end the baby's life.

According to Anne Morse, a survey statistician at the Census Bureau, American women from all economic, racial and ethnic background are having children at an older age. Black mothers and women who were not born in the US have seen their median age of giving birth increase over the past 30 years.

The decline in births to women in their 20s has been large. She said that there has been an increase in birthrates among women aged 35 to 39.

Several Republican senators told reporters that the issue of abortion is best left to the states, despite the fact that Mr. Graham's bill is not expected to pass in Congress.

Almost all of the abortions reported to the CDC occurred before the 16th week.

Younger women and those with low incomes are more likely to have these rare procedures done. Older women who have planned their pregnancies are more likely to have an abortion after 15 weeks.

The risk of a woman having a child with a chromosomal abnormality goes up to 1 in 270 for a woman in her 30's and to 1 in 60 for a woman in her 40's.

A majority of women choose to end their lives after being diagnosed with Down syndrome, a chromosomal abnormality that causes a range of physical and developmental problems.

Amniocentesis, a procedure in whichamniotic fluid is removed from the uterus and tested for chromosomal abnormality in the fetus, can only be done after 15 weeks of pregnancy.

Older women are more likely to have conditions that can make for a risky pregnancy, like hypertension, asthma, Obesity, Diabetes and cardiovascular disease, and pose more problems as pregnancies progress, straining the heart, lungs and kidneys.

The average age of first marriage has gone up from 24 in 1990 to 28, and women with college degrees have children seven years later.

Dr. Simon said a lot of women delay having children to get through at least part of their career trajectory.

You are considered high risk in the maternal care world if you are in your mid- to late 30s. You are more likely to have genetic anomalies and more likely to have additional problems.

13 states have banned abortion completely, and Georgia has banned the procedure at six weeks. Florida is the only state that doesn't allow abortion after 15 weeks. Utah has an 18-week cutoff.

The title of Mr. Graham's bill is "Protecting Pain-Capable Unborn Children From Late-Term Abortions Act." A fetus feels pain after 15 weeks, according to the measure.

The experience of pain requires the cortex of the brain to be developed by the end of the second and third trimesters.

A spokesman for Mr. Graham told a reporter to go to the website of the Charlotte Lozier Institute, which wants to end all abortions.

ImageIn a small white-walled exam room, a technician in gray scrubs holds an ultrasound wand over the abdomen of a pregnant woman. She wears a black long-sleeve shirt and covers her face with her crossed arms. The technician reads a monitor that shows the ultrasound scan on a small screen.
While a woman in her early 20s has a 1 in 500 chance of conceiving a child with a chromosomal abnormality, the risk increases to 1 in 270 for a 30-year-old woman and to 1 in 60 for a 40-year-old.Credit...Ted Jackson/Associated Press
In a small white-walled exam room, a technician in gray scrubs holds an ultrasound wand over the abdomen of a pregnant woman. She wears a black long-sleeve shirt and covers her face with her crossed arms. The technician reads a monitor that shows the ultrasound scan on a small screen.

A paper published in a journal of medical ethics suggests that other brain structures may be sufficient for an experience that resembles pain.

The author of the paper, an associate professor at the National University of Singapore, said he didn't know why Mr. Graham's bill was a cutoff. The American College of Obstetricians and Gynecologists said the law was arbitrary and unscientific.

The fetus does not have the ability to sense pain.

The fetus in the womb was not being said to be a bad day. The fetus is not as reflective as you and I are.

If an abortion takes place after 15 weeks, the fetus should be hospitalized and a physician should be present. According to a study published this year, the earliest viable fetus can be found at 22 weeks.

While technological advances have made it possible to screen for chromosomal abnormality earlier in pregnancy than in the past, getting a definitive diagnosis depends on prenatal testing: either chorionic villus sampling or amniocentesis.

Sampling can be done earlier than amniocentesis, but it can't be done safely until after 10 weeks of pregnancy, and the result isn't usually known until 14 weeks. It isn't readily available at all medical centers according to Dr. Stephen Chasen.

Amniocentesis isn't offered before the 15th week of pregnancy because of the high risks of birth defects.

If you want to check for structural fetal anomalies, which are not the same as chromosomal abnormality, you should get a comprehensive head-to-toe dissection at 20 weeks.

There are many structural anomalies that can't be seen until late in the second and third trimesters.

He said that most structural abnormality wouldn't be diagnosed or suspected before 15 weeks. If a 15-week ban were in place, women with those pregnancies wouldn't be able to consider an abortion.