Key Feature 6: In at-risk pregnant patients (ex: women with human immunodeficiency virus infection, intravenous drug users, and diabetic or epileptic women), modify antenatal care appropriately.
Skill: Selectivity, Clinical Reasoning
By the end of postgraduate training, using a patient-centred approach and appropriate selectivity, a resident, considering the patient’s cultural and gender contexts, will be able to...
My last post focused on the power of social risk factors in pregnancy, and how in the otherwise well patient - which is usual for young women of reproductive age - intervening to modify these social risk factors can make a big difference in promoting positive pregnancy outcomes. There are, however, patients who do have real medical risk and for whom medical intervention is indicated in the antepartum period. Some of these patients include women with HIV, IVDU, diabetes, and epilepsy. These patients warrant referral to an obstetrical specialist with experience in treating their medical issues, but the primary care physician will likely continue to have an active role in monitoring and following up with treatment recommendations per the consulting specialist. Some things to consider when providing antenatal care to women with these risk factors include:
For prenatal patients with HIV
-Antiretroviral therapy in the antepartum and intrapartum period has significantly decreased the rate of vertical transmission between mother and infant. Combination ART is indicated in all pregnant women who are HIV (+) and if not already started, should be initiated ASAP.
-Because risk factors for acquiring HIV are similar to risk factors for acquiring other infectious diseases, patients who are HIV (+) should have the same infectious workup as the general prenatal population but with additional testing for HCV.
-Along with ensuring the patient’s routine immunizations are up to date, some extra vaccinations indicated in prenatal women who are HIV (+) include: a TdaP booster, another dose of the routine pneumococcal vaccine, vaccination for HAV and HBV, and as far as the annual influenza vaccination goes, these patients should instead receive a dose of inactivated influenza vaccine.
-Unfortunately, breastfeeding is not recommended as there is risk of HIV transmission in breastmilk.
For prenatal patients who use intravenous drugs
-Women with intravenous drug use (IVDU) have increased risk of acquiring an infectious disease and likely face more social barriers as well. These women require a thorough workup for infection that includes routine infectious screening in pregnancy along with serology for HCV and also tuberculosis, and benefit from a more comprehensive approach to vaccinations that include those offered to women who are pregnant and who are HIV (+).
-Providing comprehensive of prenatal care in as supportive of an environment as possible can really have a positive impact on pregnancy outcomes. These women may benefit from assistance in meeting basic needs, such as with help in accessing food assistance programs, shelters, transportation vouchers, or prenatal multivitamins. Addressing and ideally transitioning to complete cessation of substance use is ideal, although a harm reduction strategy may be most appropriate in order to make some positive lasting gains. For women who use illicit opioids, replacement with methadone or buprenorphine has better outcomes on the mother and infant than medical detoxification alone, which increases the risk of relapse and overdose.
-Depending on the substance(s) of abuse, and on the women’s pattern of use if still actively using, breastfeeding may or may not be indicated. The decision to breastfeed should be individualised.
For prenatal patients with diabetes mellitus
-The mainstays of therapy for gestational diabetes are managing dietary intake and engaging in moderate physical activity, +/- insulin therapy (always first-line in a pregnant woman with diabetes prior to conception). Many women without pre-existing diabetes who develop gestational diabetes mellitus can manage their blood glucose levels with lifestyle interventions, without the need to take antihyperglycemic medications.
-Dietary management consists of planning and spreading calories out throughout the day, of which 40% should be from carbohydrate, 40% from fat, and 20% from protein. The prenatal patient then needs to perform self-monitoring of their blood glucose level with a home monitor to ensure they are able to consistently keep their blood glucose in the target range.
-Insulin should be initiated (if not already taking it) if fasting blood glucose is ≥5.3 mmol/L, if their one-hour postprandial blood glucose concentration is ≥7.2 to 7.8 mmol/L, or if their two-hour glucose is >6.7 mmol/L at least one-third of the time within a one-week interval despite dietary therapy. If women refuse to take insulin, metformin is an alternative option, although the long-term effects of metformin on the developing infant are unknown (as is the case for many medications). It is preferable that women be started on insulin if they are not able to keep to target with lifestyle interventions alone.
-If insulin is required, ongoing regular blood glucose monitoring is required to be able to adjust insulin intake accordingly. Monitoring is routinely done upon awakening (to obtain the fasting blood glucose level), along with 1-2 hours after each meal (to obtain postprandial blood glucose levels). Targets to aim for are <5.3 mmol/L fasting blood glucose, one-hour postprandial blood glucose <7.2 to 7.8 mmol/L, and two hour postprandial blood glucose <6.7 mmol/L.
For prenatal patients with epilepsy
-Seizures in pregnancy are believed to pose risk to the developing infant through fetal hypoxia from decreased placental blood flow during a seizure, or if the mom experiences postictal apnea. The other risk it poses to the fetus is through direct trauma, which could lead to fetal injury, abruption, or miscarriage. However, antiepileptic medications are also not without risk, and are associated with about a doubling in the change for a congenital abnormality. Exposure to antiepileptic medication in utero is also associated with decreased cognitive and neurological functioning later in life.
-There is limited information on which antiepileptics are safest to use in pregnancy, so in general, women are advised to continue to take the antiepileptic medication that works best for them in preventing their seizures (with the possible exception of valproate, which has been shown to pose an increased risk), in the lowest dose that is effective. Ideally, this would be optimised about 6 months prior to conception, but once pregnant, women are generally advised not to reduce their dose of antiepileptic medication to attempt to reduce risk of congenital abnormalities.
Pregnancy changes the pharmacokinetics of entiepileptic medications, so once pregnant, blood levels of these medications may be monitored on a regular basis. However, changes in serum levels of the medication by itself is not necessarily an indication to adjust the dose if seizures are well-controlled.
-It is recommended that all women who are pregnant or who could become pregnant take folic acid supplementation to prevent the risk of giving birth to an infant with a neural tube defect. In the patient without increased risk of neural tube defect, as occurs with epilepsy, this is even more important, and patients with epilepsy may be recommended to take up to 5 mg daily (in the prenatal patient at average risk for a neural tube defect, the recommended dose is between approximately 0.4 and 1 mg daily).
-In the last month of pregnancy, women may be advised to also take a vitamin K supplement, depending on the antiepileptic medication they take.
-Planning to breastfeed is recommended as taking antiepileptic medications is not a contraindication to breastfeeding.
No matter the social risk factors, medical risk factors, or lack of risk factors a patient may have, every pregnant patient can benefit from accessing resources that can help them achieve their healthiest pregnancy. A website that I find valuable to share with prenatal patients is pregnancyinfo.ca, which is linked to the sexandu.ca website as part of the public health education efforts of The Society of Obstetricians & Gynaecologists of Canada.