Second Trimester Abortion
/Second Trimester Abortion: Legal Issues
In the US, 1.2 million abortions occured in 2008.
Of these, approximately 10% took place after 13 weeks, with more than half occurring between 13 and 15 weeks.
Only 1.3% of abortions are performed at or after 21 weeks gestation.
There are varying state-level statutes that may limit the gestational age for obtaining an abortion, or the type of abortion treatment that can be offered.
The Guttmacher Institute maintains an overview of abortion laws by state. Some highlights from them:
43 states have gestational age limits on when abortion can be performed. These range from 20 weeks to viability, with some statutes currently being challenged in court that could restrict access as early as 6-15 weeks.
21 states prohibit “partial-birth” abortions, which is a misnomer that we will explain momentarily.
2 states have standing bans on standard dilation and evacuation (Mississippi and West Virginia), with an additional 9 having some enjoinment on enforcement of a ban on D&E.
26 states require waiting periods between counseling and a procedure. 18 states require specific counseling which may include false or misleading information on:
Link between breast cancer and abortion (5 states).
The ability of a fetus to feel pain (13 states).
Long-term mental health consequences of abortion (8 states).
Methods of 2nd Trimester Abortion
Dilation and Evacuation
Use of medication or mechanical techniques to dilate the cervix, followed by the use of grasping forceps to remove the fetus.
Most commonly achieved with osmotic dilators in combination with misoprostol for cervical ripening.
The success of cervical preparation at 18 weeks gestation and above may be improved with the use of mifepristone the night prior to the procedure in combination with osmotic dilators.
However mifepristone may also increase risk of pregnancy expulsion prior to the procedure, particularly if misoprostol is subsequently used for further dilation.
A variant of this technique is known by a variety of names such as “dilation and extraction” or “intact D&E,” in which further dilation is achieved which allows for removal of an intact fetus except for possible calvarial decompression.
This has been labeled in some publications as partial-birth abortion and may be restricted to some degree in a number of jurisdictions.
In order to avoid consequences associated with these laws, some experts advise preoperative feticidal injection with KCl or digoxin.
Medical or Induction Abortion
Induction may also be used to achieve abortion, however this is less-cost effective, takes more time, and is more associated with complications.
Generally, this is achieved through similar techniques for cervical ripening to labor induction -- mechanical dilators or balloon catheters, misoprostol, and oxytocin.
The most efficacious medical management is mifepristone administered 24-48 hours prior to misoprostol initiation, based on RCT evidence.
Osmotic dilators do not necessarily add benefit to misoprostol in this setting.
Preoperative feticidal injection does not shorten the duration of induction, but may be used if preferable to the woman or provider to avoid transient fetal survival after expulsion.
ACOG lists three primary techniques for medication abortion in the second trimester; ACOG and SFP note that the mife-miso regimen is the most efficacious for 2nd trimester induction abortion:
Hysterotomy or Hysterectomy
Abdominal surgery is rarely indicated for second-trimester abortion, but is occasionally indicated in the event other procedures fail or are contraindicated.
A prior cesarean or uterine scar is not an indication for hysterotomy for abortion, or for the avoidance of misoprostol, at least up until about 28 weeks gestation.
Retrospective cohort studies have demonstrated an insignificantly increased risk of uterine rupture for women with one prior cesarean delivery around 0.28%, versus rupture risk for unscarred uteri around 0.04%.
There is insufficient data to guide management on women with 2+ CDs.
However, this remains well below the established acceptable risk threshold with trial of labor after cesarean at term without misoprostol use (rupture risk for 1 prior CD at 0.5-0.7%).
The risk of rupture is suspected to increase with misoprostol use at or after 28 weeks, based on TOLAC data.
Complications and Other Situations
Mortality is 0.6 / 100k legal, induced abortions, with that rate being tied to gestational age at the time of abortion.
At 21 weeks gestation or greater, the rate of mortality rises to 8.9 / 100k procedures.
Maternal mortality for live birth is 17.6 / 100k live births in USA (or double that for 21+wk abortion, by comparison).
Postabortion hemorrhage is defined as “blood loss > 500cc and/or bleeding requiring a clinical response such as transfusion or hospital admission.”
Rates of transfusion range from 0.1 - 0.7%, with higher rates seen for medical 2nd trimester abortion.
Management is similar to hemorrhage after term vaginal delivery, ruling out retained products and uterine atony as primary causes.
Cervical laceration, uterine rupture, and abnormal placentation are also rarer but important concerns, particularly in more advanced gestational age and in women with prior cesarean delivery.
Postabortion infection is uncommon, occurring in 0.1-4% of 2nd trimester abortions.
Antibiotic prophylaxis is indicated prior to dilation and evacuation.
SFP recommends 200mg doxycycline preoperatively.
The ACOG PB recommends use of 100mg doxycycline preoperatively and 200mg postoperatively
RCT methodologies on antibiotic use support solely preoperative antibiotic use as sufficient.
Postabortion contraception placement in the form of IUDs additionally does not increase infection risk, but expulsion rates may be higher after abortion than with interval placement.
Reversible contraception of almost any kind (no diaphragms or cervical caps) can be initiated immediately post-abortion, and ovulation can resume as soon as 21 days post-procedure.