We will review the different methods of abortion currently used in the United States. Here we will give you a detailed overview of intracardiac abortions.
History of Intracardiac Abortion
The first successful intracardiac abortion was in 1978. A woman pregnant with twins chose to abort a fetus with a lethal disease with the hope of saving its twin. Since then, abortionists have used injectable medications particularly before second or third trimester dilation & evacuation (D&E) abortions, to make sure that the fetus is dead before it is delivered.
Reasons for Intracardiac Abortion
Reasons for these late term abortions include aborting fetuses who have a disability that won’t allow them to live outside of the womb, or who may have health issues for the rest of their life after birth like Down Syndrome. Injected medication abortions are also sometimes done after in vitro fertilization.
Abortion of one or more fetuses after in vitro fertilization is called “selective reduction.” Abortion after in vitro fertilization might not seem to make sense, since the couple was obviously trying to get pregnant. However, as part of in vitro fertilization, typically multiple embryos are implanted in the woman’s uterus. That way, there’s a higher likelihood of having at least one live birth.
But, sometimes multiple embryos survive the transfer process from the lab to the womb. The risk of health problems if these embryos live until birth is high. There are higher rates of preterm (early) delivery, low birth weight, brain problems, development problems, and many other issues if multiple babies are born at once rather than if just one baby is born at a time.
“Selective reduction”, then, is the process of aborting one or more of these fetuses so that the one (or two) fetus(es) that makes it to birth has (have) a higher chance of being relatively healthy. 
Whatever the reason that the woman may be aborting, these medications are injected to ensure that the fetus is not alive when it is born. Some women who are aborting fetuses with health problems believe that abortion is the “merciful” thing to do. They want to be sure that the fetus isn’t alive when it is born because then they would feel conflicted about trying to resuscitate it or watching it die.
Connection to Partial Birth Abortion
Also, the Partial Birth Abortion Act of 2003 in the United States states that killing a living fetus when it has been partially delivered from the woman’s body is illegal.  Some abortion doctors make sure that the fetus is dead before delivery so that they don’t get in trouble for breaking this law.
What are Intracardiac Abortions?
An intracardiac abortion happens when a medication being injected through the pregnant woman’s abdomen (stomach area) into the fetal heart. The medicine stops the fetus’ heart from beating.
This is often done with a medicine called Potassium Chloride. Outside of its use in abortions, Potassium Chloride is also one of several medicines given for execution of prisoners by the death penalty.
Medications to stop the fetus’ heartbeat are also sometimes injected into the amniotic fluid around the fetus, or into a random fetal body part. The most common of these medicines is called Digoxin.
Outside of its use in abortions, Digoxin was originally developed for adults to make the heart beat stronger and with a regular rhythm, or to treat an irregular heart rhythm called atrial fibrillation. Digoxin injected into the fetus is given in a lethal dose that slows the heart beat gradually until it stops.
In research studies, injected Digoxin failed to stop the fetal heartbeat in 6.6% to 13% of abortions.  In research studies, Potassium Chloride failed less than 1% of the time. 
What Percentage of Abortions are Intracardiac Abortions?
The Centers for Disease Control and Prevention (CDC) collect abortion data each year, and the results of their data collection are available online through the year 2014. Abortion data since 2014 have not yet been published. States and several large cities like Washington D.C. and New York City have the option to report their data to the CDC each year or not. For 2014, California, Maryland, and New Hampshire abortion numbers were not reported.
In the CDC report, abortion methods are classified as surgical or medical (medication). Exact numbers on how many of these surgical abortions were intracardiac abortions are not available because most of the states that report their data to the CDC did not provide this information.
The studies used in this article included from fewer than 10 up to nearly 5,000 women. Studies of digoxin included 8 women, 126 women, and 4,906 women.    Studies of Potassium Chloride included 192 women and 239 women.  In one study from Britain in 2004, where abortions by type are tracked better than in the United States, about 1% of abortions were intracardiac or injectable. 
What Happens During an Intracardiac Abortion?
On the day of the procedure, the woman first has a blood sample drawn to check her blood type, and vital signs like heart rate and blood pressure taken. She is positioned on the clinic or hospital bed as if she were having a regular pregnancy ultrasound. A numbing shot is given through a small needle into her belly. Then a long, large needle with the medicine in it is put in her belly. An ultrasound is used to determine where the fetal heart is, and when the needle is in the fetal heart.
The medicine is then injected, and the abortion doctor watches on the ultrasound screen until the heart stops. An ultrasound is often done again 30 minutes after the fetal heartbeat has stopped, to make sure that it is still stopped.
After the fetal death, the woman may be induced or may wait up to several weeks to go into labor on her own.  Sometimes, she goes into labor and delivers the stillborn baby before she can get back to the hospital. If she does deliver at the hospital, sometimes it is on a bed as with a planned live birth, and other times it is into a toilet.
A visual overview is here.
At What Point Does the Baby Die During the Abortion?
Typically, the baby dies within several minutes after a Potassium Chloride injection because the medication stops its heartbeat immediately. The abortionist watches the ultrasound until it shows that the heart has stopped. With Digoxin, fetal death can take hours.
An ultrasound may be done periodically to check when the heart stops beating. Around 30 minutes after electrical activity stops, another ultrasound is done to confirm that the heart has not started beating again. If the heart has restarted, a repeat dose of medication may be given. 
What are the Side Effects of an Intracardiac Abortion?
Side effects after a Potassium Chloride injection abortion are different from a Digoxin injection abortion. Digoxin injections are not recommended as standard practice before a dilation and evacuation abortion because they don’t decrease how long the abortion takes. Side effects include vomiting, women going into labor on their own at home or other places before the scheduled dilation and evacuation, and infections inside the uterus. Digoxin cannot be given to any woman with a history of Wolff-Parkinson-White syndrome. 
In one Potassium Chloride study, a woman suffered cardiac arrest (her heart stopped) and was successfully brought back to life. In another research study, a woman developed a life-threatening infection after the medicine was accidentally injected into her bloodstream instead of into the fetus’ heart. 
How Often Do Complications Occur?
Complications other than vomiting occurred less than 1% of the time in women who received Digoxin injections. Vomiting occurred in around 15% of women. Complications occurred less than 1% of the time in women who received Potassium Chloride injections, but when they did occur they were very severe (see above).
Sometimes intracardiac injections are given before a woman is induced to go into labor. Research shows that induction abortions can be complicated by retained placenta up to 30% of the time. Retained placenta puts the woman at significant risk for life-threatening infection. 
  Cassing Hammond MD, and Stephen Chasen MD, Management of Unintended and Abnormal Pregnancy. Ed. Paul, Lichtenberg, Borgatta, Grimes, Stubblefield and Creinin. (Wiley-Blackwell, 2009).
 Autry AM, Hayes EC, Jacobson GF, Kirby RS. A comparison of medical induction and dilation and evacuation for second-trimester abortion. Am J Obstet Gynecol 2002; 187: 393– 397.