Types of Risks
The pregnant LEO can be exposed to the following hazards associated with adverse outcomes to the pregnancy or damage to the fetus:
- Chemical hazards, include exposure to heavy metals (e.g., lead, mercury), organic solvents (e.g., benzene, formaldehyde, halogenated hydrocarbons, styrene, toluene, trichloroethylene, xylene), and pesticides.
- Physical hazards include trauma, radiation, heat, and noise.
- Biological hazards – As first responders, LEO are at a higher risk of exposure to infectious agents. Pregnancy by itself does not increase that risk. However, with some agents (e.g., novel H1N1 influenza), the risk of complication is higher during pregnancy. Pregnant officers should be aware of these risks, and follow good hygiene principles.
- The uterus extends out of the protection of the pelvis after 13 weeks and is therefore more susceptible to direct trauma (to the uterus or the fetus) after that gestational point.3
- Fetal mortality is increased during the first 23 weeks, possibly due to higher susceptibility to maternal hypotension during the first and second trimesters.4,5
- With blunt trauma, the leading causes of fetal death are maternal shock, abruption and uterine rupture.3 Direct fetal injury from blunt trauma is rare.5
- Fetal mortality rates due to maternal trauma3:
Long-term outcomes after trauma: Besides fetal loss, trauma is also associated with higher risk of preterm labor and placental bleeding.5 The risks of preterm labor and low birth weight were found to be nearly doubled in a series of patients discharged from a trauma center.8
Seatbelts: The use of seatbelts is safe and recommended during pregnancy. Proper seat belt positioning during pregnancy is the following: lap belt under the abdomen and shoulder harness between the breasts, as improper placement may result in uterine rupture.3,5 Seat belt use significantly reduced fetal mortality (five-fold reduction) in a series of cases of pregnant patients injured in motor vehicle accidents.9
Body armor: Standard body armor is not designed to protect the fetus, and typically does not cover the lower abdomen. The body armor fitted pre-pregnancy may not offer the same level of protection during pregnancy.
Lead exposure: Lead exposure during pregnancy is associated with serious materno-fetal complications, including miscarriage, premature rupture of membranes, pre-eclampsia, hypertension, and neurobehavioral effects in infants and children.10,11,12 Even at low levels, lead exposure has been associated with preterm delivery, congenital abnormalities,13 and decreased birth weight, length, and head circumference.14 Current research suggests that there is no safe lead exposure threshold for children, infants, or fetuses.12,15,16,17
Exposure to other metals: Firearm training can expose officers to other metals than lead, including barium, antimony, copper, and arsenic.18 These metals could be toxic, depending on their concentration. Lead-free ammunition, while eliminating the lead exposure, has been found to generate airborne copper levels above the Air Force occupational exposure limit.19
Exposure to organic solvents: Some organic solvents used to clean firearms, like xylene, might be harmful to the fetus.20
Exposure to noise: Noise exposure during pregnancy has been associated, in human studies, with several adverse outcomes, including miscarriage,21,22 intrauterine growth retardation,22,23,24 preterm delivery,22,25 hearing loss in babies and children,26,27 and hypertension in pregnancy.22 In a review of 10 studies on pregnancy and noise, most studies did not achieve statistical significance in showing negative effect of noise.28 The safe threshold of noise exposure during pregnancy is unknown.20,29-35
Clandestine drug laboratories and hazardous-material scenes can be dangerous. Clandestine drug laboratories can expose officers to a variety of toxic chemicals, some of which are potentially injurious to the fetus.36 Extensive exposure to exhaust fumes (such as directing traffic, tunnel and toll booth duty) might be dangerous because of exposure to carbon monoxide, benzene and other organic solvents from motor vehicles. An Italian study found that benzene exposure in traffic officers was about twice as high as in a control population of office workers.37 In the U.S., gas used for regular road traffic does not contain benzene. In developing countries that use leaded gasoline, lead exposure can be a significant problem for traffic officers.38
LEOs assigned to prisoner transport via aircraft or other high-altitude aviation may encounter radiation exposure of significance to a fetus.39-41
In animal studies, increase in maternal core temperature over 1.5°C has been shown to be teratogenic.48 While the risk of hyperthermia is not proven in human pregnancies, it is safer to prevent hyperthermia during pregnancy, especially during the first two months.49,50 Sports Medicine Australia recommends “to avoid exercise in hot conditions.”49 Exercising in a warm environment should be limited, and adequate hydration should be maintained with physical activity.
Prolonged working hours, heavy lifting, prolonged standing and heavy physical workload have been associated with preterm birth, lower birth weight and pre-eclampsia.25,46
The American College of Obstetricians and Gynecologists has published a list of medical contra-indications to exercise during pregnancy.49,51 That list could be used to recommend work accommodation to pregnant officers who are suffering from specific complications (see Appendix C).