The impact of new research on viability on the later abortion debate

Membership Call: Tuesday, October 6, 2015 at 2:00pm EST/11:00am PST

A study of hospital variation in preterm infant outcomes that was published in NEJM in May 2015 attracted popular media attention and has been used to shift hospital policy and to push legislation to limit abortion. This study found that babies were surviving at lower gestational ages than was previously thought. However, this study only followed babies without congenital anomalies, and the absence of anomalies greatly influences the ability of a fetus to survive outside the womb when preterm. Other than anecdotal evidence, to our knowledge only a few babies have been delivered before the middle of the 22nd week. There is doubt in the medical community that any fetus has survived at 21 weeks, as pregnancy is difficult to date accurately; ultrasounds during the second trimester can result in dating errors that are up to 14 days off.

In Roe v. Wade, the Supreme Court established that fetal interests can’t be put ahead of the woman’s interests until that fetus is viable. Viability is the point at which a fetus is capable of prolonged life outside the woman. At the time of Roe decision, that period was thought to be between 24-28 weeks, although it wasn’t explicitly defined in the law. Physicians previously conceptualized care of a pregnancy woman and fetus as caring for one patient, but there has been a shift in the medical model of pregnancy where now they are seen as a dyad, with the legal status of the fetus being bolstered as a pregnancy progresses. Before 24 wks 0 days, once the risks are shared with parents and the fetus is evaluated, typically neonatologists respect parents' preferences. At this stage in pregnancy, there is a 50 -75% chance of survival, with slightly higher survival rates for female premature babies. This is the same gestational age at which parents are allowed to choose whether or not to resuscitate; in states that restrict abortion at the same gestational age, this is in conflict. At the cusp of viability (23, 24, 25 wks) this changes and we see court cases that examine parent/provider conflicts. 

Research in 2012 demonstrated variation in the definition of viability provided to patients depending on who is counseling them. If MFMs provided counseling, patients were much more likely to be offered a termination of pregnancy than if fetal care specialists provided counseling. Despite exceptions for abortion in cases of lethal anomaly or life limiting anomaly, there is no consensus among MFMs about how this is defined. Better survival rates do not come without significant risk of disabilities. In preterm births at 22—23 weeks of pregnancy, there is a 14.8% chance of survival. Half of babies born at this stage have brain damage from poor respiration or too much ventilator oxygen.  Viability before 22nd week is not possible because there is inadequate lung development at this stage.

Hospital policies around termination of pregnancy can be more restrictive than state laws and can be misaligned with medical practice. Hospital policy is informed by politics, hospital bias, religious considerations and the power of providers, e.g. MFMs, family planning teams vs. neonatology. Many hospitals will not offer termination of pregnancy beyond 22 weeks gestational age in order to avoid any risk of terminating a pregnancy close to the line of viability. As hospitals reduce the viability limit or liability goes up for these procedures, more doctors won't do the procedures and later abortion won't be available to women even if it remains legal.