The Most Commonly Searched Questions About the Second Trimester of Pregnancy

“During the second trimester, the baby starts as the size of a lemon and grows substantially in length and in weight,” explains Dr. Reilly. “At this point, your body also starts to change with the growing baby. Your uterus and your abdomen are going to start to get a little bit bigger, and by 20 weeks, the baby’s up to your belly button. Weeks 14 to 27, or the second trimester, is when people really start to show. With that comes a lot of hormonal changes of pregnancy, and a lot of those symptoms are normal.”

“It’s a common misconception that people think they should be ‘eating for two’,” shares Dr. Reilly. “I actually tell my patients that you should just be eating twice as healthy. Typically, the recommendation is to increase your caloric intake by about 350 calories per day. This is about a glass of milk and a half of a sandwich or a bowl of oatmeal and a banana. So it’s not significantly much. Obviously, that’s twice that for twins and so on in multiple pregnancies.”

“Although we know that the risk of miscarriage decreases pretty significantly after the first trimester,” says Dr. Reilly, “there still is potential to have complications, such as bleeding or cramping, especially if those things become heavy or severe, or leakage of fluid that’s either large in volume or really persistent. These are all things that we should know about, because those can be signs of complications, such as preterm labor and other placental abnormalities.”

“Usually in the second trimester, some of the morning sickness has worn off,” explains Dr. Reilly. “We actually tend to refer to this as the honeymoon period of your pregnancy, because you don’t feel so profoundly fatigued and you’re not throwing up anymore. There are symptoms that are normal in the second trimester, and they tend to be related to hormonal changes. Things like acid reflux, constipation, skin changes, such as darkening of the face and sometimes the line in your lower abdomen, increased vaginal discharge, increased sex drive, and a few other things that can happen, but they’re mostly pretty mild. However, they can be bothersome, so let your ob-gyn know. There are lots of medications that are safe to treat all of these things.”

“Commonly in the second trimester, your ob-gyn is going to order what’s called the anatomy scan. This is an ultrasound that looks in depth at the parts of the baby to make sure that there are no anomalies,” says Dr. Reilly. “This, in combination with some of the blood work that we do in the first trimester, usually is going to tell a lot about whether the baby has Down syndrome or other anomalies. Around 24 to 28 weeks, we actually screen people with blood work for anemia, which is super common in pregnancy, as well as for gestational diabetes, or diabetes of pregnancy. You potentially could have follow-up testing depending on the results of all the screening that you have done, including the scan and your blood work.”

“The second trimester tends to be pretty benign and a little bit of a honeymoon period, but you still are at risk for some complications,” shares Dr. Reilly. “Preeclampsia, however rare it is, sometimes does present in the second trimester. So your ob-gyn will always be monitoring your blood pressure, and it is important to let them know if you have problems, such as persistent headaches despite taking Tylenol, visual changes, or belly pain in your right upper side, because that’s where your liver is. Additionally, pregnant women are somewhat immunosuppressed, so infections are more common. UTI symptoms are something you would definitely want to let your ob-gyn know about. Similarly, COVID-19 in this day and age is a significant concern. So you want to make sure that you have been vaccinated and boosted.”

“Usually, around 18 to 20 weeks is when you’re going to start noticing what women describe as a fluttering,” says Dr. Reilly. “Babies move starting at 10 weeks, but they’re just too small for you to feel it. Typically, women who’ve been pregnant before will feel it sooner, but I don’t really expect anyone to feel it until 20 weeks or so. It’s not a reliable marker of fetal well-being until later in the pregnancy. As far as your partner or anybody else being able to feel, I would say it is usually around more like 24 weeks and later, but it’s always an exciting experience for sure.”

“Around 26 to 28 weeks, the movements of the baby become a reliable marker of well-being,” explains Dr. Reilly. “Depending on how high risk your pregnancy is, you may get told to do it more or less often. It’s also really helpful for women to know that this is something that you can do, counting fetal movements whenever you’re wondering whether the baby is moving normally. Typically, you want to get 10 movements in two hours, but just talk to your ob-gyn, and they’ll be able to let you know how often you should be doing this if at all.”

“So the genetic sex of the baby oftentimes is able to be identified on the blood test in the first trimester that’s done to assess for chromosomal abnormalities,” shares Dr. Reilly. “But oftentimes we can add in, ‘Do you want to know the sex of the baby as well?’ If you haven’t gotten that information in the first trimester, usually around 18 to 22 weeks, when your ob-gyn does that anatomy ultrasound, we’re able to identify whether the baby is genetically male or female based off of ultrasound characteristics.”

“There’s some evidence that in the third trimester, going to sleep on your back is associated with some increased risk of stillbirth, but we actually have really good, newer data that tells us before 28 weeks, which is essentially the first and second trimesters, that there’s no risk of increased complications in pregnancy if you’re sleeping on your back,” says Dr. Reilly. “I typically tell my patients that in the third trimester, that’s the time at which, if they’re usually a back sleeper, that I would try to start going to sleep on your side. And it doesn’t really matter which side. Classically, we told people the left just because of blood supply. But ultimately, during the third trimester, sleeping on your side is totally fine. Prior to that, don’t worry. I also wouldn’t worry if you wake up on your back anyway. Just, again, if you’re in the third trimester, flip to one of your sides.”