Danger signs of pregnancy in the second trimester: What to watch for and when to call your doctor

While you can expect your body to continue experiencing changes throughout your pregnancy a few symptoms work as warning signs of pregnancy problems that require immediate medical attention.

• Severe abdominal pain and cramping: Abdominal pain and cramping can be a danger sign in pregnancy, signaling placental insufficiencies, preterm labor, or uterine rupture. Often the pain is sharp, sudden in onset, and radiates to other parts of your body. Some non-obstetric causes of sudden abdominal pain can include appendicitis, ovarian cysts, and having a fatty liver.
• Heavy vaginal bleeding: Vaginal bleeding is observed in about 25% of pregnancies. Half of these cases can progress to a miscarriage. While miscarriage is less likely in the second trimester, heavy vaginal bleeding is an ominous sign in any stage of pregnancy. Other causes of bleeding can include placental abruption, placenta previa, or uterine rupture.
• Persistent headaches or vision changes: Headaches during pregnancy can be related to hormonal changes and increased blood flow. As a consequence, you can experience tension headaches or even migraines. These headaches subside on their own with some rest. However, having a headache coupled with vision changes might be a warning sign of pregnancy hypertension or more severe pre-eclampsia, which is hypertension along with signs of organ damage such as protein in urine, headaches, and swelling.
• Severe swelling of hands, feet, or face: The increase in circulating blood flow accounts for 80% of pregnancies noticing some swelling, especially in the feet. However, if you notice swelling that is persistent, excessive, and in other parts of your body such as your face, fingers, and abdomen, it could be another warning sign of pregnancy pre-eclampsia. 
• Sudden weight gain: Routinely using a pregnancy weight gain calculator allows you to estimate how much weight gain is normal for you during each week. Beyond what’s measured, a pound of weight lost or gained is often no cause for concern. However, if you have significant weight gain in a short time, edema is often a primary cause. Diabetes or other metabolic conditions, which can result in significant weight gain, should also be ruled out.
• Decrease or absence of fetal movements: You will start feeling your baby’s movements by 18 weeks. Earlier, if this isn’t your first pregnancy. Since your baby is growing, the strength of these movements often increases as the weeks progress. On any given day, if you feel that your baby’s movements have decreased compared to the norm, check in with your doctor for other warning signs of pregnancy fetal distress. 
• High fever and chills: Fever is an indicator of infection. Mild fevers often subside on their own, with a little help from pregnancy-safe medication recommended by a doctor. A sustained fever above 38°C warrants checking, especially if you have other warning signs such as chills or a rash. 
• Leakage of mucus and fluid from the vagina: Preterm premature rupture of membranes, is when your “water breaks” before 37 weeks of pregnancy.  It is estimated to occur in about 3% of pregnancies, often signaling preterm birth. It is normal to experience some discharge during your pregnancy. However, a sudden gush of clear fluid, sometimes coupled with cramping during the second trimester can be a warning sign for preterm labor.